GIVNotes

Robert Hare
Revision 2-98
Gulfstream IV Notes

TABLE OF CONTENTS

DISCLAIMER...................................................................................................................0-i
INTRODUCTION...........................................................................................................0-iii
1. GULFSTREAM IV OPERATING INFORMATION..........................................1-1
2. ELECTRICAL POWER SYSTEMS....................................................................2-1
3. LIGHTING...........................................................................................................3-1
4. MASTER WARNING SYSTEM.........................................................................4-1
5. FUEL SYSTEM...................................................................................................5-1
6. AUXILIARY POWER UNIT..............................................................................6-1
7. POWERPLANT...................................................................................................7-1
8. FIRE PROTECTION............................................................................................8-1
9. PNEUMATICS.....................................................................................................9-1
10. ICE AND RAIN PROTECTION.......................................................................10-1
11. AIR CONDITIONING.......................................................................................11-1
12. PRESSURIZATION...........................................................................................12-1
13. HYDRAULIC POWER SYSTEMS...................................................................13-1
14. LANDING GEAR AND BRAKES....................................................................14-1
15. FLIGHT CONTROLS........................................................................................15-1
16. AVIONICS.........................................................................................................16-1
17. MISCELLANEOUS SYSTEMS........................................................................17-1
18. PERFORMANCE...............................................................................................18-1
19. MISCELLANEOUS INFORMATION..............................................................19-1
20. AIRCRAFT SERVICE CHANGE (ASC) LIST................................................20-1
INDEX..............................................................................................................................I-1
Gulfstream IV Notes
Gulfstream IV Notes i
Revision 2-98 Introduction

DISCLAIMER
These notes represent information gathered from attending class at Flight Safety
International, from other sources and through operating experience. The contents of
these notes have neither been reviewed nor endorsed by Gulfstream Aerospace
Corporation, Flight Safety, Inc., my employer: Jet Aviation Business Jets or any other
organization or individual. They are my personal notes, compiled for my benefit, and
representing my understanding of the GIV. I believe this information to be accurate, but
offer no warrantee that this is so. These notes are updated regularly as I become aware of
new information and procedures, but may not contain the latest information. Use of this
information is at your own risk. All information should be independently confirmed
through approved sources. I assume no responsibility for any results that may occur as a
result of others using this information.

These notes may be copied and distributed freely without charge and without consulting
me, provided that they are distributed intact and this disclaimer accompanies all copies.

Bob Hare
Gulfstream IV Notes ii
Revision 2-98 Introduction
Gulfstream IV Notes iii
Revision 2-98 Introduction

INTRODUCTION

This is revision 2-98 of GIVNotes. This revision includes new material culled from the
Gulfstream Customer Appreciation Breakfast Newsletters, Honeywell FMS Technical
Newsletters and contributions from several GIV pilots. My thanks to Larry Gilbert for his
assistance and contributions in improving the content. The most significant addition to
this revision was provided by Jean-Guy Boivin. Guy sent me a comprehensive set of
Honeywell FMS operating notes that I reproduced in Chapter 16. My thanks to Guy for
his contribution.

These notes are on Microsoft Word for Windows 95 (fully compatible with MS Word for
Windows version 6.0). These notes are available to all and can distributed on floppy
disks or via electronic means such as email attachments via the Internet free of charge
and kept on your computer or printed out in your office saving significant reproduction
and postage charges. File copies on floppy diskettes and unbound hard copies are
available for the cost of copying and postage.

As in the past, the basic chapter organization follows that of Flight Safety International’s
GIV Pilot Training Manual. Chapter 1, Gulfstream IV Operating Information, has been
changed to add operating limitations culled from the AFM and other sources. Chapter
19, Miscellaneous Information, was added as a catch-all area for items that do not
logically fit elsewhere. Chapter 20, Aircraft Service Change (ASC) List, is a summary of
Aircraft Service Changes that may be of interest to pilots. It is not a comprehensive
listing of available ASCs.

The objective of these notes is not to duplicate the FSI GIV Pilot Training Manual, the
GIV AFM or any other existing publication. What started out as a very modest effort to
consolidate notes from Flight Safety classes has evolved into a fairly elaborate effort to
collect GIV facts, limitations, operating tips, problems and suggestions of interest to
pilots into one source. Sources used include the Gulfstream Customer Appreciation
Breakfast Minutes, the quarterly Gulfstream Service News, and Honeywell publications
such as the FMS Technical Newsletter, published semi-annually. In many cases I have
directly quoted portions of these and other documents that might be of interest. The
quoted material is often edited and bolding and/or italics is added for emphasis. I have
tried to state the source directly below the quote for credit where credit is due and to
allow the reader to check source material independently.

In addition to collecting a wide variety of information into a single publication, I have

tried to organize and index the material so that it is quickly accessible.
Gulfstream IV Notes iv
Revision 2-98 Introduction

The best way to get in touch is by means of email. It is fast, I check it daily and you
won’t have to play phone tag. You can also try to reach me by phone or by mail at the
addresses that follow. Let me hear from you.

Bob Hare

Home Phone: 717-476-0484 C/O Jet Aviation

Internet Email: bobhare@enter.net Teterboro Airport
118 Billy Diehl Road
Teterboro, NJ 07608
Gulfstream IV Notes 1
Revision 2-98 Operating Information

1. OPERATING INFORMATION
DIMENSIONS

Wingspan 78'
Turn Radius (Wheels): 55'

WEIGHT AND BALANCE

WEIGHT LIMITATIONS -- BASELINE GIV:

POUNDS KILOGRAMS

Max Ramp: 73,600 33,385

Max T/O 73,200 33,204

Zero Fuel 46,500 21,092 (49,000 W/ ASC 61)

Max Landing 58,500 26,536
(AFM 1-1 -- 4 FEB 94)

Max fuel -- max fuel restriction of 29,500 lbs deleted in AFM 4 Feb 94

WEIGHT LIMITATIONS -- SP'S AND ASC 190:

POUNDS KILOGRAMS

• Max Ramp: 75,000 34,020

• Max T/O: 74,600 33,838

• Zero Fuel: 49,000 22,226

• Max Landing: 66,000 29,937

• Max Fuel: Same as above

(AFM 1-1 -- 4 FEB 94)
Gulfstream IV Notes 2
Revision 2-98 Operating Information

POWERPLANT

TGT

• Max Ground Start TGT: 700o C Momentary (2 sec.)

• Max Airstart 780o C Momentary 715o C -- Amber Arc
(5 Min Limit)
• Max Takeoff 800o C 5 Min 800o C -- Red Arc
• Max Go-Around 800o C 5 Min (Do not exceed)

• Max Continuous 715o C Unrestricted*

• Max Reverse Thrust 695o C 1 Minute/30 Minutes

• Max Overtemp 820o C 20 Seconds

(AFM 1-6 -- 4 FEB 94)

LP RPM

• Max Takeoff 95.5% LP 5 Min 95.5% LP -- Red Arc

• Max Go-Around 95.5% LP 5 Min
• Max Continuous 95.5% LP Unrestricted*
• Max Overspeed 98.3% LP 20 Seconds
(AFM 1-6 -- 4 FEB 94)

HP RPM

• Max Takeoff 99.7% HP 5 Min 99.7% HP -- Red

Digits
• Max GO-AROUND 99.7% HP 5 Min

• Max Continuous 97.5% HP Unrestricted* 97.5% HP -- Amber

Digits
• Min Idle Approach 67.0% HP Unrestricted

• Min Ground Idle 46.6% HP Unrestricted 46.6-% HP -- Red

Digits
• Max Reverse 88.0% HP 1 Min w/o ASC 166
Unrestricted W/ ASC 166

• Max Overspeed 102.6% HP 20 Seconds 110.0% HP -- Top

Red Arc
(AFM 1-6 -- 4 FEB 94)

* Excessive engine wear will occur if these settings are used continuously.
Gulfstream IV Notes 3
Revision 2-98 Operating Information

AIRSTART IGNITION

Airplanes SN 1000 thru 1249 without ASC 304:

• Duty Cycle: 30 sec on and 30 sec off

-OR-
On for 5 minutes and off for 30 minutes

Airplanes SN 1250 and subs and airplanes SN 1000 thru 1249 with ASC 304:

• There is no duty cycle time limitation for continuous airstart ignition with ASC
304 installed.

(AFM 1-7 -- 5 JAN 96)

• Normally off for takeoff and landing.

• Use when there is standing water, slush or snow

(AFM 2-18 30 SEP 94)

FUEL SYSTEM

TEMPERATURES:

Engine Fuel Max 120o C 15 Minutes 120o+ C -- Red Digits

90o C Unrestricted 90o+ C -- Amber
Digits
Engine Fuel Min for start -40o C Unrestricted -40o- C -- Red Digits
For opening power levers -30o C Unrestricted
(AFM 1-6 -- 4 FEB 94)

Fuel Tank ------ 54o+ C -- Red Digits

------ Between -- White
------ -40o- C -- Red Digits
(AFM 1-9 -- 4 FEB 94)

• Max Fuel Load: No limitation other than the maximum allowable ramp/TO
weights.

• Max Fuel Imbalance: Above 55,000 GW -- 400 lbs (most restrictive simplification)
55,000 and below -- 2000 LBS
(AFM 1-10 -- 4 FEB 94)

• One boost pump per side may be off per side if the Fuel Tank temp >0o C
Or if using anti-ice additive.
Gulfstream IV Notes 4
Revision 2-98 Operating Information

(AFM 1-20 -- 4 FEB 94)

• For balancing fuel in flight with tank temps below 0o C and no prist, maintain all four
boost pumps on and open the Intertank Valve to gravity feed with ½ ball slip towards
light tank.

Note: Intertank valve is not normally to be used in flight accept in this case or with a
dual boost pump failure.

• For fueling to maximum level, position A/C wings level, nose down
(AFM 5-33 4 FEB 94)

• Left/right fuel low-level warning messages come on at approximately 650 lbs.

May erroneously indicate at a higher level if boost pumps are off.

(AFM 5-33 4 FEB 94)

OIL SYSTEM

OIL TEMPERATURES

• Max: 120o C 15 Min

105o C Unrestricted

• Min Start: -40 o C

• Min Temp for throttle movement: -30 o C
(AFM 1-6 -- 4 FEB 94)

APU

START PARAMETERS/LIMITATIONS:

• Oil Pressure Light should come on within 10 sec of Master Switch being turned on.
• Oil pressure light must be out by 95% RPM.
• RPM should be 100% ± 3%. (AFM 2-7 4 FEB 94)
• Wait one minute for EGT to stabilize before selecting APU air on.
• On shutdown, wait until below 95% before selecting APU air off.
• RPM and EGT indicators remain powered for 30 sec after Master Switch selected off.
• Avoid cycling Master Switch above 10% RPM or overtemp may result.
• Wait until below 10% RPM before selecting Master Switch off.
(AFM 2-8 15 JUL 94)
Gulfstream IV Notes 5
Revision 2-98 Operating Information

EGT

Start EGT UP TO 60% RPM: 988 o C 732 - 1000o C -- Red Arc

o
60 - 100% RPM: 821 - 732 C (linear decrease as RPM increases)

Running EGT 680 - 732 o C -- Amber Arc

(AFM 1-11 -- 4 FEB 94)

RPM

Max Overspeed 110% RPM 110 - 120 -- Red Arc

104 - 110 -- Amber Arc
0 - 104 -- White Arc
(AFM 1-11 -- 4 FEB 94)

AIRSPEED LIMITATIONS

VMO/MMO 340 KTS/.88M --See AFM for specifics--

(AFM 1-15 -- 4 FEB 94)

VA 170 KTS

Max Turbulence Penetration 270/.75

Flaps Extended (VFE/MFE) Speed

Takeoff 10 - 250 KTS

T/O/Appr 20 - 220 KTS
Landing 39 - 170 KTS (180 KTS W/ ASC 190 & SP)

Landing Gear Speeds

VLO 225 KTS (Blow Down -- 175 KTS max)

(Once Down -- 250 KT Max)
VLE 250 KTS
(AFM 1-13 -- 4 FEB 94)

VMCA 104 KTS

VMCG 111 KTS

Max Windshield Wiper Speed 200 KTS (AFM 1-14 -- 4 FEB 94)
Gulfstream IV Notes 6
Revision 2-98 Operating Information

LANDING GEAR

Max altitude for Landing Gear Extension/Operation 20,000' MSL

FLAPS

Max altitude for Extension/Operation AT 39 20,000' MSL

TAKEOFF AND LANDING

Max pressure altitude for T/O and Landing 15,000'

Temperature Limitations for Takeoff/Landing

Sea Level -40 TO 50o C

(AFM 1-17 -- 4 FEB 94)

Max Runway Slope +2% (Uphill)/ -2% (Downhill)

(AFM 1-19 -- 4 FEB 94)

Max Demonstrated Crosswind: 24 KTS

Max Approved Tailwind 10 KTS (AFM 1-17 -- 4 FEB 94)

Max Tire Speed: 182 KTS (195 KTS W/ ASC 190)

(AFM 1-14 -- 4 FEB 94)

COMPONENT FAILURE LIMITATIONS

(Not to be used for flight release)

Mach Trim Compensation Inoperative MMO 0.75

Yaw Damper Inoperative Prior to T/O Max Fuel 9,000

In Flight above F;180 Min Speed 220 KTS
In Flight below FL180 Min Speed -- See Reference
(AFM 1-20 -- 4 FEB 94)

Mach Trim And Yaw Damper Inoperative MMO 0.75 and Max Alt 41,000' MSL

Above FL180 Min Speed 220 KTS

Below FL180 Min Speed -- See reference
Gulfstream IV Notes 7
Revision 2-98 Operating Information

(AFM 1-20 -- 4 FEB 94)

If Ground Spoilers Not Operative for Takeoff, must have:

• Anti-Skid
• 20 Flaps
(AFM 1-23 -- 4 FEB 94)

Anti-Skid Failure -- Brake-By-Wire and HMAB Aircraft:

If Anti-Skid failed for T/O must have: • Ground Spoilers

• 20 Flaps
• Cowl & Wing Anti-Ice off
(AFM 1-23 -- 5 JAN 96)

Brake Messages -- Brake-By-Wire Airplanes:

Takeoff Not Permitted if "BRAKE FAIL" or "BRAKE PEDAL" messages cannot

be cleared (described in AFM Section 5)
(AFM 1-23 -- 5 JAN 96)

ANTI-ICING
TAXI AND T/O

When Temps below 8o C with: Visible Moisture

-Or- Precipitation
-Or- Wet Runway

Engine run-up at 85% HP for one minute at 60 minute intervals and before T/O

- AND -
Min Cowl Anti-ice pressure: 4 PSI (AFM 1- 21 -- 4 FEB 94)

IN FLIGHT

Cowl Anti-Icing required when static OAT is less than -20o C at mach 0.75 and when less
than -24 o C at mach 0.80 with visible moisture (Temperature range varies relative to
mach number. See AFM reference).

Cowl anti-icing not required below -40o C.

(AFM 1-22 -- 4 FEB 94)

Autothrottle is not permitted for T/O or go around with Wing A/I -- ON.
Gulfstream IV Notes 8
Revision 2-98 Operating Information

SPEED BRAKES

Do not extend with: Flaps greater than 22o

-OR-
Gear Down

Do not pull Flight Power Shutoff with Speed Brakes extended

(AFM 1-23 -- 4 FEB 94)

BRAKE SYSTEM

Takeoff Not Permitted if "BRAKE FAIL" or "BRAKE PEDAL" cannot be cleared.

(AFM 1-23 -- 4 FEB 94)

ANTI-SKID

If Anti-Skid Failed for T/O must have: • Ground Spoilers

• 20 Flaps
• Anti-Ice off
(AFM 1-23 -- 4 FEB 94)

THRUST REVERSERS

Cancellation should be initiated by 70 KTS to be at idle thrust by taxi speed.

One minute deployment limitation every 30 minutes w/o ASC 166.

May be used for taxi at low thrust settings w/ ASC 166

(AFM 1-23 -- 4 FEB 94)

ENGINE SYNCHRONIZER

Must be off for takeoff and landing.

(AFM 1-23 -- 4 FEB 94)

LANDING LIGHTS

Max ground operation5 minutes

(AFM 1-25 -- 4 FEB 94)
Gulfstream IV Notes 9
Revision 2-98 Operating Information

FLIGHT MANAGEMENT SYSTEM

Navigation above 85 N or S with NZ-9101 or later versions of FMS software is

permitted.

FMS navigation based solely on GPS sensor data is not permitted unless using navigation
software version NZ4.1 or later.

(AFM 1-24 – 6 Sep 96)

PERFORMANCE COMPUTER

May not be used for flap 10 takeoffs at airports above 9000'.

AUTOTHROTTLE

• Not Permitted for T/O or go-around with Wing Anti-Ice ON

• Not Permitted BELOW 50' AGL on approach (AFM 1-25 -- 4 FEB 94)
• Autothrottles go to “HOLD” at 60 KTS (Clamping) (AFM 2-14 -- 20 FEB 90)

AUTOPILOT

Not Permitted below: • 200' AGL On Takeoff

• 50' AGL On Approach (AFM 1-25 -- 4 FEB 94)

STANDBY ELECTRICAL POWER SYSTEM (SEP)

Commonly referred to as the “ABEX”.

Limitations with use: • Min HP RPM 67% HP

• Speed brakes must be deployed slowly (5 sec)
(AFM 1-25 -- 4 FEB 94)

Permitted with SEP on: • Normal landing gear deployment not permitted*
• Landing not approved*
*
The last two limitations have been lifted. If the power drops off line during
either event, recycle the Standby Electrical Power System Master Switch.
Landing is now permitted provided that auto ground spoilers & reverse thrust are
not used.
(AFM Rev. 10)
Gulfstream IV Notes 10
Revision 2-98 Operating Information

Will not function if the left engine is shut down (requires Combined Hydraulic Power).

OIL GRADES

Mixing of oils not recommended but permitted if operationally necessary.

(AFM 1-28 -- 4 FEB 94)

ELECTRICAL SYSTEM
If no charge is indicated immediately after start, a battery charger failure may be
indicated.
(AFM 2-6 20/02/90)

NUTCRACKER SYSTEM

Do not depress Nutcracker Test Switch while on ground -- simulates an inflight situation
unlocking Landing Gear Handle solenoid.

ENGINE START

APU/External Air pressure normally 25-50 PSI.

Should not fall below 20 PSI during start. (AFM 2-14 4 FEB 94)

For crossbleed start, advance operating engine to maintain 25-30 PSI.

(AFM 2-16 15 JUL 94)
(AFM C-12 4 FEB 94)
(AFM E-7 6 DEC 96)

Max APU alternator load is 35% for start (30% for high elevation airports or high
ambient temperature conditions.

Start cycles: 3 -- 30 sec/cycle w/3 min pause, then 15 min wait. (AFM 2-14 4 FEB 94)

Max demonstrated tailwind starts -- 25 KT.

Ignition should occur within 10 sec of opening HP cock. (AFM 2-15 4 FEB 94)

Max start TGT 700o C

If temps exceed 650o C a fault must be suspected.

Gulfstream IV Notes 11
Revision 2-98 Operating Information

Min Idle 46.6% HP (AFM 2-15 4 FEB 94)

See Cold Start Procedure for temps below -10o C (Section 5)

(AFM 2-16 15 JUL 94)

Airstart -- 25,000' or below speed 200-324 KCAS

Start Valve should close (extinguish SVO light) by 44.5% HP RPM.

PRESSURIZATION
Manual Pressure Control – When on ground, make sure that the outflow valve is fully
open.

APU Bleed Air – During ground operations, when the APU air is selected ON, the
engine bleed switches should be selected OFF.
(AFM 2-21 18 OCT 96)

Selecting engine bleed air switches OFF will help extend the life of the bleed air valves
by de-energizing the solenoids.
(AFM 2-22 30 SEP 94)

FLIGHT CONTROLS
GUST LOCK

Ensure that Combined and Flight hydraulic pressure is depleted before engaging the gust
lock.
AFM 2-23 15 JUL 94)

System pressure is sufficient to break the locking system.

Remove the gust lock prior to either engine start.

If the gust lock is engaged with hydraulic pressure in the Combined or Flight systems,
the gust lock may not disengage. If this should occur, pull the Flight Power Shutoff
handle up to isolate the flight controls from system pressure, remove the gust lock
and restow the Flight Power Shutoff handle full down.

Caution: Failure to fully reseat the Flight Power Shutoff Handle full down can result
in a “Single Rudder Limit” light to illuminate on the EICAS fault warning display.
Gulfstream IV Notes 12
Revision 2-98 Operating Information
Gulfstream IV Notes 1
Revision 2-98 Electrical

2. ELECTRICAL SYSTEMS
POWER SOURCES

VSCF SYSTEM
Two AC Generators -- 115 VAC/variable freq/30 KVA/3 phase

Two AC Converters are used to create a constant 115 VAC/400 HZ frequency/23

KVA/3 phase power and 28 VDC at 250 amps.

The combined alternator/converter system is known as the Variable Speed Constant

Frequency (VSCF) System.

AC ALTERNATORS
AC is used because it requires smaller gauge wires, smaller motors and has less heat loss
than in DC motors

The term generator is the same as alternator -- they are interchangeable terms.

With a failed alternator bearing, flight may continue for 15 hours loaded (converter on)/
50 hours unloaded (converter off)

These times represent average times to failure. GAC recommends that the generator
be changed ASAP.

Generators have failed in as little as seven hours after the indication began after
normal engine shutdowns between legs.

Monitor affected engine EVM indications for excessive vibration.

Power Failure Considerations

If the Left or Right DC & AC Power Fail Lights come ON, the failure may be a generator
or converter failure.

There is no way to tell which has failed in flight.

To check on the ground, a special patch cord is needed to connect the APU generator
output to failed side converter.
Gulfstream IV Notes 2
Revision 2-98 Electrical

If the converter output resumes, then the generator is bad.

A patch cord may be purchased from GAC or built from plans available.

Designation: Converter Patch Cable/Alternator Test Cable: P/N 1159SEAV30002-1

ALTERNATOR/CONVERTER TROUBLESHOOTING

It is possible for a bad alternator to fail a converter. If the converters are swapped and a
bad alternator exists, it is possible to ruin the other converter as well.

To avoid this possibility, take the converter from the failed side and connect it to the
APU alternator or to the good engine alternator. If the problem follows the converter, the
converter is bad. If the swapped converter now works, the alternator on the failed side is
bad and should be replaced. No further damage should occur.

APU ALTERNATOR
Identical to the engine alternators: 115 VAC/variable freq/30 KVA/3 phase.

The electrical frequency is maintained at 400 HZ by governing the APU to a constant

speed rather than by using a converter.

CONVERTERS

CONVERTER SWITCHES

May be turned on/off in any order -- just don't switch both on/off simultaneously (gang
bar style) -- may damage AC BPCU.

CONVERTER REDESIGN STATUS

Most of you know that AlliedSignal and Gulfstream are in the midst of a major converter redesign
due to poor fleet reliability. Both companies feel so strongly about this redesign being successful
that they have assigned Program Managers who review the program plan together biweekly. The
two main modules, power supply and wiring harness, are being redesigned.

• The Transformer-Rectifier Module (TRM) is the most complex component. It was determined
early that the original redesign required modification, impacting the first targeted completion date.
This remains the long pole in the tent; however, it is currently in final design. The first production
prototype is expected to be ready in October 1997.
Gulfstream IV Notes 3
Revision 2-98 Electrical

• The Converter Control Module (CCM) and Power Supply are in prototype testing, which is going
well.

• Incorporation of the latest technology into the above components has reduced the number of
parts, including printed circuit boards, and made them more open and easier to manufacture. The
module stress testing plan was finalized last week.
(GAC Breakfast Minutes – 08/12/97)

CONVERTER FANS

There are five fans per Converter spinning at 22,500 RPM

The fans are considered very reliable

Converter Fan Message -- Amber “LR CONV FAN FAIL”

If it comes on, it indicates a failed fan. The failure sensing is based on a reduced current
draw by the fans.

The aircraft may be operated for 25 hours with a failed fan.

It must be visually confirmed that only one fan is failed before each takeoff.

The blades on an operating fan will appear invisible due to the high RPM.

Nothing must be stuck into the fan enclosures – any object will destroy the blades.

Only the four external fans may be visually inspected for function. The fifth fan is
internal.

If the four external fans are running, it may be assumed that only the internal fan is failed.

If one of the external fans is failed it is possible that the internal fan is also failed
precluding further operations.

The mechanical fan fail indicators, which are mounted one on each converter, show:

 Black and gray sections when all fans are operating.

 Black and white sections when one or more fans have failed.

A second fan failure may give no indication or may cause fan message to extinguish

A shutdown of the converter should be considered when on the ground.

The ambient temps and ram air effect should keep converter temps within limits
while in flight.
Gulfstream IV Notes 4
Revision 2-98 Electrical

The fan fail indication is illuminated when a high current is sensed resulting from a
seized fan.

It is possible for the wire to burn through, expecially if a second fan seizes, opening
the circuit and stopping current flow.

This will extinguish the fan fail light, even though the fan remains failled.

ASC 285 – Failed Fan Latching. This ASC will latch the EICAS failed fan indication
ON preventing a second fan failure or wire burn through from removing the fan fail
indication.

POWER FAILURE MODES

AC/DC Power Failure

A total converter power failure may be the result of a failed converter, a failed alternator
or a feed failure.

Failure Of The AC Output from the converter results in the converter being shut down
automatically.

The converter cooling fans are powered by converter AC output. Failure of the AC
output will fail the cooling fans and result in a converter overheat.

DC Power Failure -- A DC only failure is possible. An AC only failure is not thought to

be possible.

The failure may be the DC portion of the converter

Could also be bad wiring connections between the alternator and the converter --
check this before replacing converter

Turning OFF a Converter During Taxi

Bring aircraft to a stop before turning OFF a converter

May cause:  Brakes to go to bang bang

 Nosewheel steering to fail

Neither of the above should happen but have occurred

-509 Converter -- An upgrade version

Solid sides in place of current perforated sides

Gulfstream IV Notes 5
Revision 2-98 Electrical

EMI producing test points removed (GIV's are very EMI noisy)

Converter Drop-Off At High Elevation/ Cold Weather Airports

High elevation airport/very cold weather operations result in lower than normal engine
idle speeds.

It is possible for one or both converters to drop offline in these conditions, resulting in
much bus cycling and disturbance to cabin occupants.

As a precaution to avoid converter drop-off, leave the APU running with the APU
alternator selected on for all ground operations under these conditions.

TRANSFORMER-RECTIFIER UNIT (TRU)

The normal source of DC electrical power for all busses is the DC output of the
Converters when operating. The TRU provides DC electrical power when the APU or
External AC are the only source of power or when the DC output from a converter fails.

A non-regulated 300 amp 28 VDC power source (non-regulated means that voltage drops
as demand increases).

25-28 VDC is OK.

TRU Power Source

Primary: Left Main AC Bus

Alternate: Right Main AC Bus (will autoswitch)

TRU Red Bar Indication (DC Voltmeter)

The red bar lights on the EPMP voltmeter at 25.9 volts or below.

25.9 volts would mean an approximate 80% TRU load (240 amps).

25.6 volts would be expected at 85-100% TRU load (255-300 amps).

The red bar is not significant with voltage 25.0 VDC

ASC 112 replaces the original TRU with another 300 amp TRU with better heat
dissipation ($10,000)

Installed at factory in 1156 & subs

Gulfstream IV Notes 6
Revision 2-98 Electrical

Normal TRU Load -- on APU power only, DC users require 85% of TRU capacity

An 85% load will cause voltage to drop to about 25.6 VDC with red bar

Voltage should remain at 25.6 VDC thru rated max load of 100%

This voltage is not harmful to TRU or user components

Users designed to work at 24 VDC

TRU Hot Light: Check that the air intake is clear. Located in the bottom center of the
right avionics bay below the PDB CB panel

Have been 4 cases of TRU hot lights since start of G-III AC aircraft

3 were caused by lint in the cooling intake

Before cleaning intake, pull “R AC TRU” CB on PDB panel to stop fan -- turns at a
very high RPM -- can damage

Battery Backup Power If the TRU is powering the DC systems and the load causes the
output voltage to fall one-half volt below the battery voltage, the battery tie busses will be
connected to the Essential DC Bus.

E-INVERTER
115 VAC/400 HZ single phase 0.8 KVA output (800 VA or 800 watts).

To check e-inverter output, select Essential on the voltmeter panel and observe
voltage/frequency.

The switch light shows switch position only.

E-inverter output powers the Essential AC Bus Phase A only.

Phases B & C normally power outfitter added items, no flight critical items

 Smoke Detectors
 GPWS
Gulfstream IV Notes 7
Revision 2-98 Electrical

STANDBY ELECTRICAL POWER SYSTEM (ABEX)

Hydraulically driven generator.

Uses Combined Hydraulic System only.

Second largest user of hydraulic fluid after the landing gear.

The Standby Electrical Power System uses 16-18 gpm of the Combined Hydraulic
System’s 22 gpm max output.

The landing gear starves the ABEX on lowering and ABEX starves the brakes on
landing roll (The aux hydraulic system will kick in if combined hydraulic pressure
drops.)

Powers Essential AC & DC Bus

Turns ON when shutoff valve opens (power removed) letting Combined Hydraulic
pressure into the hydraulic motor

Shutoff valve powered closed by Essential DC Bus

Loss of Essential DC power allows the shutoff valve to open, automatically

activating the standby generator.

Standby Electrical Generator Output

 5 KVA AC -- Converted to 150 amps DC by TRU and sent to Essential DC Bus.

 50 amps DC -- Converted to 800 VA (0.8 KVA) AC by the E-Inverter and sent to
Essential AC Bus.

By selecting the E-Inverter on before selecting the TRU switch, less bus power
switching is experienced.

The order of selection is not really critical.

FLIGHT IDLE

Minimum idle with Standby Electrical Power System ON is 67% HP -- Flight Idle will be
maintained automatically if the Main DC Busses are dead.

You must maintain 67% HP RPM manually if the ABEX is operating with power to the
Main Busses.

LANDING WITH ABEX ON

Gulfstream IV Notes 8
Revision 2-98 Electrical

Landing Gear Extension

The Standby Electrical Power System no longer must be shut off for normal hydraulic
gear extension and landing.

If the Standby Generator drops off line during gear extension, cycle the Standby
Electrical Master switch OFF then ON.

If the Standby generator output starts fluxuating, cycle the Standby Electrical Master
switch OFF then ON.

If desired, the SEP may be turned OFF for gear extension by selecting the "STBY
ELEC" switch to OFF.

Leave TRU & E-invert switches – ON.

Reselect "STBY ELEC” switch to ON after gear extension.

Flight Spoilers (Speed Brakes)

Ground spoilers should be selected off of landing using the SEP.

Flight spoilers should be manually deployed at a slow rate (5 seconds for full extension).

Effect of the Standby Electrical Power System on the DU's

When the Standby Electrical Power System is selected ON in older GIV's:

With main busses powered, DU #3 will automatically go to top compact

DU's #2 & #4 will automatically will Red-X

Effect of the Standby Electrical Power System on Avionics

After turning on the Standby Electrical Power System:

 FMS #1 must be re-initialized

 The Transponder must be reselected (goes to standby)

Inflight Test of Standby Electrical Power System

Must turn OFF both of the converters and APU generator to test.

(OR -- pull both L & R DC SENSE CB's, pilot's CB panel, H14 & I14)

Then power up the Standby Electrical Power System normally.

Gulfstream IV Notes 9
Revision 2-98 Electrical

The #1 FMS must be Re-initialized after the power switch.

Dual Converter Failure Landings

Ground spoilers will not work -- Left Main DC control

Speed brakes are available manually

Reversers are available

The crew should consider taxiing clear of the runway and shutting down.

Engine idle remains at Flight Idle (67% HP RPM)

Brakes run off of the Auxiliary Hydraulic Pump (due to low Combined System
pressure with the Standby Electrical Power System on).

The Aux Pump runs off of the Battery Tie Bus (batteries only with chargers off-
line) with the Standby Electrical Power System powering the Essential DC
Bus.

Selection of the Standby Electrical Power System ON with Converters Running

It is possible to maintain converter power output to the Main AC & DC Busses and use
the Standby Electrical Power System to power the Essential AC & DC Busses by using
the following technique:

 Leave converters selected ON

 Pull the Left and Right DC sense circuit breakers (pilot CB panel H14 and I14)
These breakers are on the circuits that tell the Standby Electrical Power System
that the Main DC Busses are dead. It is their only function.
 Hard select Essential DC Bus to Battery

 Select Standby Electrical Power System ON w/ converters ON

Will lose DU #2 (and DU #4 with auto top compact feature)

 Must maintain min idle at 67% HP RPM manually (DC Busses still powered,
inhibiting auto flight idle at altitude.

MAIN AIRCRAFT BATTERIES

Two 40 amp-hour nickel-cadmium (nicad) batteries wired in parallel are isolated from the
ships interior in sealed and vented stainless steel “bomb” boxes.
Gulfstream IV Notes 10
Revision 2-98 Electrical

Ventilation fans in the battery compartment turn on at 90o F and off at 70o F when the
Battery Switch(es) are ON.

There are two exterior battery switches -- one forward of the entry door and one on the
left aft fusilage.

Either external power switch turns on both Batteries and the lower anti-collision light.

In the baseline GIVs, an external power switch must be selected on in order to close the
main entry door.

In the GIV SP, SN 1156 + subs., the door closing switch may be used without an external
power switch selected on.

Using the door closing switch (but not the external power switch), only the #2 battery
will be used in powering the auxillery hydraulic system to close the door.

Using both the external power switch and the door switch will result in both batteries
being used.

After multiple door closures using only the external door closing switch, it will be
normal to see a lower voltage on the #2 battery.

Sense and control wires fasten at the cannon plug located below the normal power cou-
pler (Elcon Connectors).

Sense temperature and Battery state

Must use this type of battery (G-III AC or GIV -- not G-II/G-III DC)

Battery Power Only -- 20 minutes of battery power plus two APU start attempts (AFM)

This endurance assumes compliance with the AFM Dual Converter Fail Procedure
load shedding (Checklist page E-42):

 Crossflow -- OPEN
 Three boost pumps -- OFF

Should try APU starts within the first 15 minutes (GAC)

DEEP DISCHARGE

On the ground, if both Battery Switches are left ON -- battery depletion will occur in 4-6
hours with a minimum load on the system.
Gulfstream IV Notes 11
Revision 2-98 Electrical

Expect to see 9-11 volts on the batteries

Battery voltage will sag to 3 volts at which point the Battery Switch Relays will drop
out disconnecting the batteries from the Battery Tie Bus.

Expect a 6-8 volt recovery from the batteries, after resting for four hours, raising the
voltage to 9-11 volts.

The Battery Switch Relays need 17 volts to pull back in (reconnect the battery to
the Battery Tie Bus).

Battery Relays Sticking -- There are 44 known cases of External Battery Switches being
turned OFF with anti-collision light off but Battery relay stuck closed draining batteries

Sometimes switch stays ON due to switch bounce.

A de-bounce circuit was designed to eliminate the problem (approximately SN 1155

and subs)

BATTERY CHARGERS
The GIV utilizes a constant current/variable voltage charging system.

Each battery charger supplies 38 amps of electricity to its respective battery at voltages
varying from 20 to 33 volts DC depending on the battery’s current state of charge. When
the batteries are fully charged, you can expect to see 0 amps 3 amps (due to meter
error).

Charger voltage varies from 20 - 33 volts (10% overcharge) increasing with battery
charge level.

At full charge (after 3 to 75 minutes) voltage drops to 27.75 V steady.

A normally discharged battery will take approximately 3-10 minutes to charge.

If charge occurs significantly faster than 3 minutes minimum, suspect corrosion on

the monitor plug at the battery case.

A fully discharged battery may take up to 75 minutes to become fully charged.

The battery chargers are designed to shut down charging after a ninety-nine minute
charge.
Gulfstream IV Notes 12
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A charge of over ninety-nine minutes is assumed to be a battery malfunction.

Battery Temperature Sensing

Chargers sense their respective battery temperature.

Stop charge at 140oC and resume at 130oC (thermal runaway occurs at 160oC).

Chargers will not charge their batteries if battery voltage is 4 volts or less

With ASC 054 charging can forced with batteries at or below 4 volts (see below).

Max Charger output is 50 amps each

Charger TR Mode

Chargers also have TR Mode (Transformer Rectifier) where they can provide up to 50
amps each of 27.7 volt DC power to the Essential DC Bus

If the battery chargers are charging their batteries and the aux hydraulic pump is acti-
vated (60 amps off of the Battery Bus), batteries will discontinue normal charging
until the Charger discontinues TR Mode.

When Chargers are in TR Mode, batteries will receive a charge at a partial

rate.

If the auxiliary hydraulic pump is on (66 amps powered by 33 amps from each
charger), 17 amps will continue to go to each battery, if charging is required,
until the battery tie bus load is removed.

Charger’s 50 amps - 33 amps =17 amps available to charge its battery.

Battery Charger Unflagged Failure

It is possible for a battery charger to fail without a FAIL light illuminating. If this is
suspected, perform the following check:

1. Turn the Aux Pump on for 20 seconds.

2. Turn off the Aux Pump.
3. Check for a positive battery charge on both ammeters.

Battery Charger Switching (ASC 054)

Original baseline configuration: Turning ON one battery switch turns ON both Battery -
Chargers.
Gulfstream IV Notes 13
Revision 2-98 Electrical

If one Charger is bad, the bad charger's CB must be pulled or both batteries must be
turned OFF.

ASC 054 puts each Charger on its own Battery switch

It also allows a battery to be charged from below 4 volts by switching the battery
override switch (at the external AC plug enclosure).

This can be used to get home and then the effected battery must be deep-cycled.

160 man hours to install

To check if you have ASC 054:

With both main AC busses powered, turn OFF one battery switch. If the off side
battery voltmeter drops from 27.7 to 24.0 volts and other side does not, then ASC
has been incorporated.

EMERGENCY BATTERIES (E-BATTERIES)

All E-Batteries and IRS batteries are interchangeable.

E-Batt endurance target is 30 minutes

Standard E-Batteries -- Nickel-Cadmium E-Batteries are produced by Utah Research

and Development Corporation (URDC)

Original standard batteries installed in GIV

Lead-Acid E-Batteries -- Produced by Secure-A-Plane, are considered more reliable.

May be used in place of the URDC batteries with no modification.

E-Batt Discharge Rates -- E-Batteries have an internal sensing circuitry that is always active and
drawing current. In addition, nicad batteries naturally self-discharge.

URDC E-Batteries will discharge to one-half capacity in 15 days at 25 degrees Celsius

(GAC Breakfast Minutes -- 03/26/91)

Some operators are reporting 50% discharge in one week in high temps

E-Batteries are unusable at 50% charge.

To avoid flat URDC e-batts charge weekly for 30 minutes.

Gulfstream IV Notes 14
Revision 2-98 Electrical

This seems to be the main source of unreliability in these units.

The Secure-A-Plane lead acid E-Batt does not discharge when inactive.

It can set uncharged for extended periods with a full charge.

E-Batt Charging

AC power on the main AC busses is required for charging.

E-Batteries charge from Essential DC

E-Batteries stop charging at 122oF.

The forward avionics compartment can reach this temp in summer

May need to close entry door and turn on a pack.

URDC NiCads

The batteries have built in chargers and initially charge at a high rate and then drop to a
lower rate.

To increase charge rate, pull the E-Batt CB every 15 minutes to force to high charge
rate.

Secure-A-Plane Lead Acid E-Batts

The lead acid emergency batteries have on internal charger and charge automatically off
of essential DC line power.

Emergency Battery Configurations

The green A/C comes with 4 E-Batteries standard.

#1 & #2 E-Batteries and one E-Batt for each of two standard IRS’s.

E-Batt options:

#3 E-Batt for: DDRMI #1

Nav #1
ADF #1

One E-Batt for the #3 IRS/AHRS

Gulfstream IV Notes 15
Revision 2-98 Electrical

"Thru" vs. "Or" System

If an E-Batt is dead, its users may or may not work

If the forward (#1) e-batt is pulled from its rack, then all of that e-batteries consumers are
disabled, including pedal brakes (the electric brake ECU on baseline GIVs) under all
conditions.

The system design that causes this to happen is called a "THRU" system.

ASC 231A or SN 1214 & subs. makes changes the system to an "OR" system allowing
brakes and other users to work using primary power inspite of a dead or removed forward
e-battery.

E-Batt Consumers (when on E-Batt power only)

Flap Indicator -- lighted and functions

Brake Accumulator Gauge -- lighted and indicates zero PSI despite having pressure
charge

Pressurization Panel – Will be lighted but not operational (Essential DC power is

required to control the bleed air valves).

If E-Batteries come ON in normal powered flight: INVESTIGATE!

E-Batteries coming on in the absence of obvious electrical system malfunctions most

often occurs as the result of a Essential DC bus power source shift.

Early GIVs were heavy EMI emitters which caused the e-batts to come on regularly.
Now EMI interference is low. An e-batt activation usually means a more serious
electrical switching problem now.

Check EPMP for all green power sources

If the lights are not all green, find what source is powering the Essential DC bus and
why.

If the Essential DC Bus source is the battery bus:

Check Battery ammeter for discharge immediately.

If a battery discharge is found, it must be dealt with expeditiously with load

shedding measures.
Gulfstream IV Notes 16
Revision 2-98 Electrical

IRS BATTERIES

IRS BATTERY CHARGING

IRS batteries charge from the Right Main DC Bus

Emergency power need not be armed and IRS's need not be selected to NAV to charge
(Howard Good 5/93).

URDC NiCad IRS Batteries charge at the low charge rate only despite being identical to
the E-Batteries.

A bad IRS Battery may possibly be revived by placing in an E-Batt rack with its high
charge rate (NiCad batteries only).

IRS Battery Fail If an IRS Battery fails during IRS power-up, try turning IRS OFF and
then back ON.

Failure may have resulted from a transient test glitch.

EXTERNAL AC
To receive External AC Power:

 At least one battery switch must be ON

If the battery voltage is 4 to 12 volts, one battery switch must be ON and the
Battery Override Switch selected ON at the external AC plug panel.

If the battery voltage is below 4 volts, ASC 054 must be installed for the above
procedure to work.

The battery switch(es) may be turned OFF after power is established if desired.

 Aux Power Switch ON

To charge batteries from External AC Power:

 At least one Battery Switch must be ON (two with ASC 054.)

 Batteries must have at least 4 volts or use the override switch at the External AC
plug with ASC 054.
Gulfstream IV Notes 17
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Note: When not charging batteries, it is a good idea to leave the Battery switches OFF

This technique avoids discharging the batteries if External Power is turned OFF from
outside or if power fails while the A/C is unattended.

It is possible to start the APU from External AC with good batteries – not recommended.

However, if batteries are depleted and charging off External AC Power and a start is
attempted using External DC Power, one or both Chargers may blow.

Disconnect External AC during APU start -- ALWAYS!

EXTERNAL DC
To connect External DC Power to the aircraft, the Aux Power Switch must be ON.

The Battery switches may be ON or OFF (batteries need not even be in the aircraft).

Note: It is a good idea to leave the Battery switches OFF during External DC Power
operations.

Avoids discharging the batteries if the External Power is turned OFF from outside or
fails.

Avoids discharging the batteries during aux pump operations common in maintenance
(see the following section).

With External AC Power or APU generator providing AC Power, External DC Power

will only power aircraft DC systems if TRU is inoperative or the TRU CB is pulled.

The TRU has priority over External DC Power

When the sole source of power, External DC normally powers:

 L/R Main DC Busses

 Essential DC Bus
 Essential AC Bus (via the E-Inverter)

but not normally:

 Battery Tie Bus

Gulfstream IV Notes 18
Revision 2-98 Electrical

For External DC Power to power Battery Tie Bus, both Battery Switches must be –
OFF (disconnecting the batteries from the battery tie bus).

External DC cannot be connected to the Battery Tie Bus while the batteries are
connected to avoid an unconditioned charge of the batteries by External DC Power

The K-16 relay connects DC External power to the Battery Tie Bus only if the
Battery Switches are off.

For example: To run the Aux Hydraulic Pump off External DC power—

Battery Switches -- OFF

Can start APU

Cannot charge batteries (Battery Chargers require AC power off the Main AC Busses).

With External DC power connected and Battery Switches are ON, only the batteries and
Chargers (if Main AC power is available) power the Battery Tie Bus regardless of any
other power available to the aircraft.

Battery Tie Bus directly powers:

1. Aux Hydr Pump (66 amps):  Flaps

 Brake Accumulator
 Gear doors
 Entry door (closing)

2. APU starter (400 amps)

So – External DC power connected and on and battery switches ON, only the batteries
(and battery chargers in TR mode) power Aux Pump and APU starter.

To power the Aux Pump and APU starter through External DC, the battery switches must
be selected off.

ELECTRICAL SYSTEM BUSSES

AC BUSSES
ESSENTIAL AC BUS

Essential AC Phase B & C Users

 Smoke/Flame Detectors
 Ice Detector
Gulfstream IV Notes 19
Revision 2-98 Electrical

 GPWS
 TCAS
 GPS

All of the above are lost when on Batteries or Standby Electrical Power System only

DC BUSSES
ESSENTIAL DC BUS

The Essential DC Bus consumes 150 amps nominally.

This can run as high as 160-170 amps on some aircraft.

The maximum allowable draw on the Essential DC Bus is 171 amps.

A maximum DC output of 150 amps can be provided by the Standby Electrical Power
System (ABEX) through the TRU.

For aircraft that have Essential DC Bus loads in excess of 150 amps, the
difference is made up by battery discharge. Battery load meters should be
monitored and load shedding of the Essential DC Bus should be considered when
the Essential DC Bus is powered by ABEX and a battery discharge is
experienced.

ESSENTIAL DC BUS POWERED BY BATTERY POWER

LOSS OF THE ESSENTIAL DC BUS

Batteries will be drained if the Essential DC Bus is selected (auto or hard) to the Battery
position (Battery Tie Bus) and no load shedding measures are taken..

Situation: A GIV was crossing the North Atlantic eastbound when the number 1 and 3
display units started flickering and then failed. The crew checked the EPMP to trouble
shoot and found the EPMP completely black with no switchlights or digital readouts.
The pilots did not know what the problem was and were not aware that the converters
were still providing power to the Main AC & DC Buses.

Action: The crew tried hard selecting the Essential DC Bus to Left or Right Main DC
Busses. This did not work. They then deselected the functioning converters in order to
select the Standby Electrical Power System (ABEX) ON. It functioned normally giving
them the Essential AC and DC Busses only. Both Left and Right Main AC and DC
Busses were lost when the converters were turned OFF.
Gulfstream IV Notes 20
Revision 2-98 Electrical

Analysis: During flight, the Essential DC auto switched to the Battery Tie Bus power
source. This was reflected on the Essential DC portion of the EPMP with the Battery
Switch ON lights illuminated. The crew did not notice this switchover. The E-Batteries
came on during the Bus power changeover. The crew did notice this and reselected the
E-Batt “ARM” Mode. There was no abnormal indication on the main instrument panel.

As a result of the auto selection of the Ess DC Bus to battery, Main DC power became
unavailable to the Essential DC Bus. The Essential DC Bus was carrying a load of 180
amps. Each Battery Charger was able to take 50 amps leaving a 40 amp drain on each 40
amp-hour battery. Both batteries fully discharged before the crew was aware of the
problem. Once the batteries were discharged, the Battery Chargers were overloaded and
voltage dropped below required minimums .

This led to the Essential DC Bus failure. With the loss of the batteries and Essential DC
Bus, the EPMP lost power to its switchlights and digital readouts (four redundant so-
urces, two battery & two Essential DC). This made interpretation of the electrical
system status very difficult.

In this case the problem was a result of a failure in the electrical Bus Fault Computer and
the auto and manual switching capability was no longer functional for the Essential DC
Bus. The Essential DC Bus was locked into the Battery Tie Bus as its only source of
power.

Solution: With the essential DC bus selected to the battery tie bus, but not locked
their by a fault condition.

Had the problem not been caused by a failed fault computer locking the DC bus to the
battery tie bus, the crew could have hard selected the Essential DC Bus to the Left or
Right Main DC power source even though the EPMP panel appeared dead.

All switch functions would still have been normal.

Solution: With a fault condition locking the essential DC bus to the battery tie bus.

With the essential DC bus locked to the battery tie bus through a computer fault, there is
no opportunity to select a main DC power source. The crew had two choices.

1. Load shed the essential DC bus so that the drain on the batteries is eliminated and
continue running the essential DC bus on battery charger TRU power. Main AC
and DC busses would continue to receive power from their respective converters.

2. Select the Standby Electrical Power System ON to power the essential DC bus
with the converters continuing to power the main busses.

1. Avoiding use of the Standby Electrical Power System with Functioning Main
Busses
Gulfstream IV Notes 21
Revision 2-98 Electrical

If the Essential DC Bus is isolated from its normal power sources (Left or Right Main DC
Busses) and is discharging the batteries:

Attempt to load shed away the battery discharge and power the Essential DC Bus
through the Battery Chargers (TR Mode).

This will avoid the many limitations that come with use of the Standby Electrical
Power System.

2. Selection of the Standby Electrical Power System ON with Converters Running

The crew could have maintained converters ON to power the Main AC & DC Busses and
used the Standby Electrical Power System to power the Essential AC & DC Busses by
using the following technique:

 Leave converters selected ON

 Pull the Left and Right DC sense circuit breakers (pilot CB panel H14 and I14)
These breakers are on the circuits that tell the Standby Electrical Power System
that the Main DC Busses are dead. It is their only function.
 Hard select Essential DC Bus to Battery
 Select Standby Electrical Power System ON w/ converters ON
Will lose DU #2 (and DU #4 with auto top compact feature)
 Must maintain min idle at 67% HP RPM manually (DC Busses still powered,
inhibiting auto flight idle at altitude. Pilot Induced Essential DC Bus Failure --
Non-APU Engine Shutdown

During engine shutdown without the APU running, the Essential DC Bus is normally
hard selected to the "BATT" position to avoid standby electrical pump startup on engine
wind-down (due to interruption of Essential DC power).

(See Engine Shutdown without the APU Running, page 14).

If the Essential DC Bus is not returned to the auto position prior to the next flight, and
this condition is not noticed and reset by the next crew, the batteries will remain locked to
the Essential DC Bus as its only source of power and will drain down eventually leaving
the Essential DC Bus dead, the EPMP black and DU's 1 & 3 blank.

Battery Chargers will continue to output 50A each, but will be of insufficient amperage
to meet demand, resulting in bus voltage being below user minimums, causing them to
drop off line.

This condition may be reversed even after the EPMP panel goes black by selecting the
essential DC bus to auto. With a dark panel, interpretation of the situation is difficult.
Gulfstream IV Notes 22
Revision 2-98 Electrical

"SENSOR DC BUS ON BATT" – will annunciate in blue on the EICAS on SN 1253 &
subs. to alert the crew to this condition (ASC 327 is available for installing this option).

The modification provides this CAS annunciation anytime that the Essential DC Bus
is powered by the Battery Tie Bus (battery power only).

LOSS OF ESSENTIAL DC BUS -- EFFECT ON PRESSURIZATION

Both Bleed Air Valves are powered open and held open by Essential DC Bus power.

Loss of Essential DC power to the valves will cause both to close shutting off all
bleed air flow for pressurization.

So -- if you have pressurization, you have the Essential DC Bus regardless of the
EPMP status.

(See Pneumatics -- Chapter 9)

BATTERY TIE BUS

Normally unpowered

When powered -- battery switch lights illuminate amber ON.

If power is required of the battery tie bus, battery tie contactors close automatically,
connecting both batteries to the battery tie bus and illuminating the on lights in the
battery switches.

Battery Tie Contactors close when any of the following items are selected on:

 Aux Hydraulic Pump (66 amps)

 APU start (400 amps)
 Essential DC Bus Battery hard select (150 amps)
 Standby Electrical Power System (ABEX).

If the "BATT" switch is manually hard selected on the Essential DC Bus portion of the
EPMP, the Battery Tie Contactors close allowing the batteries and Chargers (in TR
Mode) to power the Essential DC Bus.

The Essential DC Bus is disconnected from the Left Main DC Bus.

Any demand by the Essential DC Bus in excess of the combined charger provided
100 amps is supplied by the batteries.

Battery Tie Contactors close during APU start.

Gulfstream IV Notes 23
Revision 2-98 Electrical

400 amps required for the start: 100 amps from Battery Chargers (50 each)

300 from batteries (150 each)

- or -
200 amps from each battery if the Chargers are not powered.

Becaused of the heavy contribution made by the batteries, good batteries are required
for an APU start.

BUS CONTROL AND POWER DISTRIBUTION

ELECTRICAL POWER MANAGEMENT PANEL (EPMP)

EPMP POWER SOURCES

All switchlights on the EPMP give positive indication of power to the associated bus
except for the E-Inverter switchlight.

It shows switch position only.

Power to the Essential AC Bus must be confirmed using the Essential AC Voltmeter.

"EPMP POWER FAIL" indicates that one of four redundant power sources is lost.

Two power sources are from the Essential DC Bus.

Two power sources are from the batteries.

All four sources feed the Remote Power Supply which powers the EPMP digit lights.

Switching OFF a Battery switch will illuminate the "EPMP POWER FAIL" message.

TOTAL POWER FAILURE TO EPMP

Causes a dark panel.

Loss of all four power sources fail lights in switches and digital readouts.

Switches continue to select power sources manually and automatically.

Gulfstream IV Notes 24
Revision 2-98 Electrical

EPMP
Blank Panel
Can be caused by overhead light panel dimmer switch dead spot.

Try turning knob to get out of dead spot.

The same problem could cause the panel to show all "8's".

Still occurring on late serial number units (10/95).

EPMP SWITCHING AND METERING

E-Inverter Switchlight -- This is the only EPMP power source switchlight that is a
position light only.

When the E-Inverter is selected, you must check the AC volts and cycles to confirm
that the E-Inverter is actually online.

Battery Ammeters -- Reflect current into or out of Batteries.

Battery Voltmeters -- actually indicate the Battery Charger output voltage, when the
chargers are powered, battery voltage otherwise. The chargers are powered when the
Main AC Busses are powered and the Battery Switches are selected ON.

DC Volts -- With APU for power source, indicates TRU output

With converters ON, indicates Converter DC output.

EPMP Voltmeter Sources

Source Selected AC Volts [115] Freq [400] DC Volts [28.0]

Essential Essential AC Bus Ess DC Bus
Right Right Converter AC Right Converter DC
Left Left Converter AC Left Converter DC
Aux APU Gen TRU

POWER MANAGEMENT

Typical Electrical Loads

Converter AC Loads -- 15-25% not balanced.

Converter DC Loads -- 50-55% as high as 80% have been seen (125-140 amps).
Gulfstream IV Notes 25
Revision 2-98 Electrical

LOAD SHEDDING

DC Converter Failure: If a DC Converter fails (250 amp capacity) and the TRU comes
online (300 amps capacity) -- no load shedding is required -- all users are covered.

If the TRU does not come on after the DC Converter failure, the remaining converter
picks up the entire DC load for the aircraft.

Will show approximately 110% (280 amps) on the EPMP DC Power Control Panel.

To drop down the DC load

Can:  Turn OFF any two boost pumps (40 amps DC each).

Reduces load to 200 amps of available 250 amp.

It may not be possible to turn them on again if Prist is not being used and the
fuel temperature is below 0 C.

Better:  Hard select the Essential DC Bus to Battery (isolates Essential Bus from
Converter power).

Essential DC Bus normally has a 150 amp load.

Battery Chargers will come online in the TRU mode (50 amps DC each)
leaving a 50 amp load on the Batteries.

 Turn OFF both Main Boost Pumps (40 amps each off the Essential DC Bus).

The remaining load on the single Converter DC output is 130 amps (280a - 150a =
130a).

The remaining load on the Essential DC Bus is 70 amps

(150a - 80a (2 pumps) = 70 amps) easily handled by the Chargers.

(See Essential DC Bus page 2-19.)

Boost Pumps -- 40 amps DC each (16% of converter output/13% of TRU).

Mains powered by Essential DC.

Alternates powered by Right Main DC.

MAIN DC BUS POWER SOURCE CYCLING

Gulfstream IV Notes 26
Revision 2-98 Electrical

If a Main DC Bus starts cycling rapidly from its own converter to the opposite converter,
then to TRU and back to its own converter:

It is due to a failing regulator on the DC portion of the converter allowing DC voltage

to sag under load forcing the DC Bus Power Control Unit to seek another source of
power for the Main DC Bus.

Once the DC Converter is unloaded, the voltage rises to normal and the DC BPCU
senses this, returning the Main DC Bus to the bad DC Converter to restart the cycle.

Procedure:

 Hard select the Bus to the TRU

 Write up problem

All digits in the EPMP are field replaceable. GAC will send digit modules.

POWER DISTRIBUTION BOX (PDB)

Power in from External AC/DC, APU and Converters.

Power out to four Main Buses & two Essential Busses.

Located behind the CB Panel in the right radio rack along with:

 The six electrical busses

 TRU
 The Remote Power Supply Unit
 The AC & DC Bus Power Control Units (BPCU's)

Contains all of the feeder cable circuit breakers -- not labeled.

All CB’s that are not TRU or boost pump CB's are feeders.

BUS POWER CONTROL UNITS (BPCU)

Provides the logic behind the EPMP auto bus power source switching.

There is one AC BPCU and one DC BPCU units.

The BPCU’s control the EPMP digital readouts.

Completely automatic.
Gulfstream IV Notes 27
Revision 2-98 Electrical

Checks 31 functions of power quality constantly.

Includes:  Over/under voltage

 Over/under currant
 Phase shift

Will inhibit connection to or disconnect from any bad power source.

The BPCU’s are located in the forward right radio rack -- bottom shelf.

BUS FAULTS

ESSENTIAL DC BUS FAULT

With an Essential DC bus fault -- Do not experiment, follow checklist procedures

exactly!

An Essential DC bus fault can be quickly identified by a DC Bus Fault Light illuminated
and ALL DUs & SGs powered and working (all tubes working).

Wait 10 seconds between breaker resets.

The voltmeters can be checked for an immediate indication of excess load.

Once the fault is isolated to one of the main DC feeder CBs on the PDB circuit
breaker panel, the circuit breakers for all of the power users for that feeder can be
pulled and then reset one at a time until the source of the fault is found. Once the
faulty circuit is identified, all other circuit breakers on that feeder can be reset,
minimizing lost components.

Consult the Gulfstream/Flight Safety Emergency/Abnormal Pilot (red)Checklist, page

N-51 for listings of CBs associated with each feeder circuit.

ESSENTIAL AC BUS FAULT

With an Essential AC Bus fault (AC Bus Fault light resets and returns), the Essential AC
Bus is powered by the E-Inverter:

If the voltage is abnormal -- then the fault lies on Phase A.

If the voltage is normal -- then the fault lies on Phase B or C.
Gulfstream IV Notes 28
Revision 2-98 Electrical

CIRCUIT BREAKER PANELS

Red faced CB's are Essential Bus CB's.

Black faced CB's indicate Main Bus CB's.

Circuit breakers on the Power Distribution Bus (PDB) labeled as ACCESS, PILOT or
COPILOT are bus feeder circuits.

CIRCUIT BREAKER LOCATOR CODES

:
Circuit Breaker Panels

Pilot's Panel (P) – The panel behind the left pilot’s seat.

Pilot's Overhead Panel (PO) – The panel above the left pilot's seat.

Co-Pilot's Panel (CP) – The panel behind the right pilot's seat.

Co-Pilots Overhead Panel (CPO) – The panel above the right pilot's seat.

Individual CB Locations

Columns lettered at bottom left to right (A - N).

Rows numbered from inside edge top to bottom (1 - 14).

MISCELLANEOUS
Do not make power source changes during taxi.

Can cause failure of brakes/nosewheel steering.

Come to a stop first, make change and resume taxi.

Gulfstream IV Notes 1
Revision 2-98 Lighting

3. LIGHTING

TAXI LIGHTS

Landing lights are limited to 5 minutes use on ground

ASC 131 turns off the taxi lights on gear retraction.

Gulfstream IV Notes 2
Revision 2-98 Lighting
Gulfstream IV Notes 1
Revision 2-98 Master Warning System

4. MASTER WARNING SYSTEM

WARNING INHIBIT

When selected, works: Below 400' AGL with gear handle up or down
Above 400' AGL with gear handle down.

Inhibits all blue and amber tones and Master Caution Lights, except:

Amber "CPL DATA INVALID"

SPZ-8000 Aircraft with SWLPs: Inhibits the Master Warning Lights and aural warning
tones if the SWLP is in auto:

 APU FIRE
 CABIN DFRN - 9.8
 CABIN PRESSURE LOW
 DAU 1-2 MISCMP-MSG
 MAIN DOOR (NOT BAGGAGE)

SPZ-8400 and ASC 345 Enhanced Avionics aircraft: Master Warning Lights and aural
warning tones cannot be inhibited for any red warning messages.

When inhibited, all warning lights/messages will activate except for Master
Warning/Caution Lights and appropriate tones.

Out of 400' Warning Lights will illuminate & tone will sound.

Not recommended for use in approach and taxi.

GAC pilot advisory board recommends SWLP in auto for takeoff.

AIRCRAFT TAKEOFF CONFIGURATION WARNING

Components checked for proper configuration:

 Speed brakes stowed

 Flaps 10o or 20o
 T/R locked

Warning armed at:  80% HP RPM for EICAS warning

 Throttle lever position for Standby Warning Light Panel warning
(baseline GIV only).
Gulfstream IV Notes 2
Revision 2-98 Master Warning System

To avoid configuration warning when using emergency flap lever.

Flaps must be positioned exactly at 10o or 20o.

Best way to set:

Before engine start, position flaps at approximately 15o with emergency flap
handle using Auxiliary Hydraulic System (for slower response and thus more
accurate positioning).

Crack throttle until the configuration warning sounds then work flaps down
toward 20o until warning ceases.

ENGINE FIRE WARNING SYSTEM

Warning System Test -- a 100% continuity test of the system with the SWLP in Manual

SPZ-8000 EICAS

Normal test: 10 lights. Test with broken sense loop: 7 lights.

1. Fire Test Loop A 1. Fire Test Loop (only one will light)
2. Fire Test Loop B 2. Master Warning Lights (L)
3. Master Warning Lights (L) 3. Master Warning Lights (R)
4. Master Warning Lights (R) 4. EICAS -- "ENGINE HOT"
5. EICAS -- "ENGINE HOT" 5. EICAS -- "ENG FIRE LOOP ALRT"
6. EICAS -- "ENG FIRE LOOP ALRT" 6. SWLP -- "ENGINE HOT"
7. SWLP -- "ENGINE HOT"* 7. SWLP -- "FIRE DET LOOP"
8. SWLP -- "FIRE DET LOOP"*
9. Fire Handle red light
10. HP Shutoff Handle red light

* -- With DU's ON and SWLP in manual.

SPZ-8400 EICAS (No SWLP)

Normal test: 8 lights. Test with broken sense loop: 5 lights.

1. Fire Test Loop A 1. Fire Test Loop (only one will light)
2. Fire Test Loop B 2. Master Warning Lights (L)
3. Master Warning Lights (L) 3. Master Warning Lights (R)
4. Master Warning Lights (R) 4. EICAS -- "ENGINE HOT"
5. EICAS -- "ENGINE HOT" 5. EICAS -- "ENG FIRE LOOP ALRT"
6. EICAS -- "ENG FIRE LOOP ALRT"
7. Fire Handle red light
8. HP Shutoff Handle red light
Gulfstream IV Notes 2
Revision 2-98 Master Warning System

Lights that will not light with broken sense loop:

 Fire Handle light

 HP Cock light
 Affected Loop A or B segment in switch light

FAULT TEST

The manual test checks lights -- no circuit testing.

The automatic testing runs constantly cyclically testing system capacitance and resistance while
the system is powered.

VALID FIRE WARNING

In the event of a valid fire warning, you will see the following: 8 lights.

 "ENG FIRE LOOP ALRT" on EICAS

 "ENG DET LOOP" on SWLP (SPZ-8000 system only with SWLP selected manual)**
 "LOOP A/LOOP B" on effected side (2)
 Fire Handle light on effected side
 HP Cock light on effected side
 Master Warning lights (2)

** -- Not available on SPZ-8400 equipped GIV's

Note: If the Fire Handle light is lit, assume that you have a fire!

After bottle #1 is discharged:

If fire warning lights are out, push fire test button.

Look for Loop A & B lights ON.

If they are out, assume that loops are burned through and fire bottle #2.

FIRE HANDLE

The white button under the fire handle will release the handle manually.

The handle will unlock automatically in a fire warning.

Pull forcefully to full up position before discharging bottle.

Gulfstream IV Notes 3
Revision 2-98 Master Warning System

Partial extension could result in extinguisher charge being lost when fired.

"ENGINE HOT LIGHT"

If valid warning, there will always be secondary indications

 High oil and/or fuel temp (fuel cools oil)

 High TGT
 High vibrations on EVM

There have been no valid engine hot lights in the GIV to date (FSI 10/93).

There was one false fire warning associated with Skydrol contamination in the aft equipment bay
(FSI 11/94)
Gulfstream IV Notes 1
Revision 2-98 Fuel System

5. FUEL SYSTEM

FUEL QUANTITY

MAXIMUM PERMITTED QUANTITY

The maximum limitation of 29,500 lbs has been lifted.

It is not a structural limitation.

Max ramp and maximum TOGW restrictions must still be observed.

MAXIMUM FUELING TECHNIQUE

To get the maximum fuel onboard:

 Park wings level, nose elevated.

 Pressure refuel at 55 PSI.
 Use cold fuel.

FUEL PROBES

There are 21 fuel probes per wing tank

The probes use a resistance-capacitance system to measure fuel density directly in weight
units.

There have been some fuel probe problems giving some false fuel quantity indications.

Rapid Shifts in Fuel Quantity

Results from either:  Water in fuel (different densities sensed).

 A loose connection to a probe.

AUTO FUELING SHUTOFF VALVES

There are two shutoff systems per tank:

 Float Shutoff (Normal full fuel shutoff mechanism)

Gulfstream IV Notes 2
Revision 2-98 Fuel System

 Overpressure Shutoff (backup to the Float Shutoff).

The Remote Shutoff Switches work through the Float Shutoff Valves to stop flow of
fuel to each of their tanks.

Activating a Remote Shutoff Switch in the cockpit closes a drain valve in the Float
Chamber simulating a full tank and causing the float to shut off flow.

This is the reason that these shutoff switches are slow acting.

This is a valid test of the Float Shutoff System.

The Pressure Shutoff System must be tested at the fueling receptacle.

PRESSURE DEFUELING

Must use caution:

Right fuel tank drains first causing aircraft to settle to the left preventing the
Interconnect Valve from equalizing tanks.

Open the interconnect valve – drain slowly and observe the fuel balance to avoid an
excessive split.

BALANCING FUEL TANKS AIRBORNE

Use the Cross Flow Valve if:  Using Prist.

-or-
 Tank Temperature greater than 0O C.

If the above conditions are not met -- use the Intertank Valve.

Fly with one-half ball towards the direction of desired flow (step on the fuller tank).

LOW LEVEL LIGHTS

Low Level Lights are designed to illuminate at 650# on each side.

Erroneous Low Level Light indications may occur at significantly higher fuel levels with
boost pumps OFF.

Proper indications will resume when a boost pump is turned on.

Gulfstream IV Notes 3
Revision 2-98 Fuel System

DIFFERENCES BETWEEN THE EICAS AND THE STANDBY FUEL

QUANTITY INDICATORS

Quantity differences are often noted between the main fuel indicator on the EICAS and
the standby fuel quantity indicators.

The differences are generally in the 200-600 pound range.

There is no consensus as to which gauge is more accurate.

If fuel critical, it would be conservative to believe the lower reading

indicator.

If weight is critical, the higher of the two indicators should be believed.

Both indicators receive the same quantity information from fuel probes via the
signal conditioner.

The main fuel indicator signal additionally passes through the DAU’s for digital
processing.

This additional processing step may cause the difference between

indications.

BOOST PUMPS

Considered very reliable – 25,000 hours mean time to failure (MTTF).

Very few failures.

POWER CONSIDERATIONS

Main & alternate boost pumps are AC motors.

AC induction motors do not spark.

Contain internal inverters to convert DC power sources to AC.

Main boost pumps are powered by the Essential DC Bus.

Alternate boost pumps are powered by the Right Main DC Bus.

Fuel Boost Pump Switch OFF lights indicate switch position only, not boost pump status.
Gulfstream IV Notes 4
Revision 2-98 Fuel System

AUTO CHANGE

If the Main Boost Pump Switch is ON and the Alternate Pump Switch is OFF, and a main
pump fails:

 The Main Boost Pump Switch Off light will not come on.
 The Alternate Boost Pump Switch Off light will extinguish.
 The Alternate Boost Pump Switch On light will light.

Auto Change Test (Before APU start).

 All Boost Pump Switches -- OFF

 Select Left alternate Pump Switch -- ON
 The OFF light goes out because of switch position
 The pump will not run because no Main Bus power
 Look for Left Main Boost Pump Switchlight to come on
Despite switch not being selected due to auto switching
 Look for Left Fuel Pressure Low Light to extinguish.

BOOST PUMP FREEZING PROBLEMS

Water can freeze in fuel sumps locking up boost pumps when they are turned OFF and
tank fuel temp is below 0oc.

AC pump motors have low starting torque.

If a pump stalls on ice slush, it may cause the pump CB to pop and the “MAIN
PUMP FAIL” or “ALT PUMP FAIL” message to illuminate.

Can happen on ground during a quick turn after a long leg.

Can reduce possibility or possibly alleviate by using Wing A/I on descent (The
effectiveness of this technique is in doubt).

MISCELLANEOUS
FUEL PRESSURE LOW LIGHT (RED WARNING) WILL COME ON IF:

 Pressure downstream of the filter is less than 15 PSI

 Both boost pumps are OFF on one side w/ crossflow closed
 With cross flow open and all pumps OFF.

IF FUEL FILTER LIGHT (RED WARNING) ILLUMINATES:

 If there is a deviation in engine indications – shutdown.

 If cold out on ground and happens shortly after start.
Gulfstream IV Notes 5
Revision 2-98 Fuel System

Then it may be ice crystals in fuel filter.

Allow engine oil to warm up and heat fuel.
 If fuel filter light goes out at lower fuel flow -- Believe the indication.

FUEL LOW LEVEL LIGHT WITH PLENTY OF FUEL

Suspect clogged fuel ejector pump is clogged. Fuel is not being pumped into the hopper
tank quickly enough to maintain normal full hopper tank level.

This is also possible when fuel quantity is checked after the aircraft has set for a while
with boost pumps off. Fuel can drain back into main tanks enough to activate the low
level floats in the hopper tanks. The indication will disappear when a boost pump is
turned on.

QUICK TURNS

During quick turns after extended high altitude operations operators have experienced
fuel caps frozen on and frozen boost pumps.

This problem may be avoided by using wing heat during the descent (hot air vents into
the wheel well area, although the effectiveness of this technique is doubted by some
experts).

If the freezing occurs on the ground, try turning both packs OFF and using wing Anti-Ice
off the APU air.

NOTE: Failure to turn OFF both of the packs first will result in the the APU over-
temping before it can self limit
.
Gulfstream IV Notes 6
Revision 2-98 Fuel System
Gulfstream IV Notes 1
Revision 2-98 Auxiliary Power Unit

6. AUXILIARY POWER UNIT

The GIV uses the same APU as on the G-III.

APU bleed air is available on the ground only – it is disabled in the air.

When the APU Master Switch is turned ON, the APU low oil pressure light will come
on when the air intake door is open.

Battery Switches can be turned off without flaming out the APU (this is different from
the G-III).

APU Exceedances

The SPZ-8000 exceedance system is tripped by an APU fire indication.

The SPZ-8400 exceedance system is tripped by an APU fire, high EGT or high RPM.

EGT

The normal EGT is 660C. The normal range runs from 650-670C.

The amber EGT light is located above the EGT digital gauge.

The EGT light illuminates at 704C.

The APU flames out automatically when the EGT reaches 730C.

RPM

The normal RPM range is 97-103% (1003).

The APU RPM light illuminates at 104%.

Overspeed Test – This test is conducted on APUs that have the High Altitude
modification.

An overspeed condition is not likely on an APU under normal ground/low altitude

operations.

It is more likely under high altitude operations (above FL 350) when lightly loaded.

The overspeed test is run on high altitude APUs before starting for this reason.
Gulfstream IV Notes 2
Revision 2-98 Auxiliary Power Unit

LOAD CONTROL VALVE (LCV)

The APU Load Control Valve limits APU EGT by restricting bleed air output. As EGT
increases towards maximum allowable, the load control valve starts to reduce the bleed
air pressure.

Under high elevation, hot temperature conditions, APU bleed air output can be as
low as 17 PSI.

The engines require 25 PSI minimum for start.

APU FIRE

The APU will shut down automatically if an APU fire is sensed.

The intake door will close automatically.

APU ALTERNATOR

The blue “APU ALT OFF” light indicates that the alternator is operating but is not
selected ON.

The amber “AUX AC PWR FAIL” annunciation indicates that the APU alternator has
failed or the APU is being shutdown.

The amber “APU ALT HOT” annunciator message probably indicates a bad alternator
bearing.

Shut off the APU. There is no vibration monitor to watch the APU alternator.

The amber “APU ALT BRG FAIL” normally indicates that the APU alternator main
bearing has failed.

The same limitation applies to the APU alternator that applies to the main
alternators:

15 hours of operation loaded (alternator selected on).

50 hours of operation unloaded (APU running, alternator not selected on).

The annunciation will remain illuminated.

A false “APU ALT BRG FAIL” light has be observed. If it comes on during the
APU start and then extinguishes itself, the cause is moisture in the bearing sensor.
Gulfstream IV Notes 3
Revision 2-98 Auxiliary Power Unit

Remote Indication Box -- Before the indicators on the APU Remote Indication Box in
the aft compartment can be reset, a battery switch and the APU master switch must be
selected on.

DISPATCH WITH A FAILED CONVERTER

Allows dispatch with a failed converter -- This is the only advantage to ASC 96 – High
Altitude APU.

MEL Limitations:  FL 410 ceiling (with High Altitude APU/ELWS)

 FL 220 ceiling (without High Altitude APU)
 Within one hour of airport (Cancelled)
 Day/VMC
 APU Alternator is used for T/O, enroute and landing
 TRU is operative
 Associated converter electrical cables are secured.

APU STARTING
LOW BATTERY VOLTAGE START

APU start -- 22 VDC is minimum required on the batteries (AFM).

It has been started with as little as 19 VDC (never at 18 VDC).

Procedure:

 Boost pump -- OFF (40 amps)

 E-inverter - OFF (40 amps)(hard select Essential AC to Left or Right Main
bus).
 Boost Pump & E-Inverter back ON after APU start.

The APU was designed to start using one good battery.

If one is excessively low -- turn OFF Battery Switch for that Battery.

APU will start using External DC Power with flat batteries (See the following section).

APU START WITH EXTERNAL POWER

EXTERNAL DC POWER APU START

The APU may be started with External DC Power (Batt Switches off).

If starting the APU off of External DC power, turn External AC off for the start.
Gulfstream IV Notes 4
Revision 2-98 Auxiliary Power Unit

Cannot charge batteries (must be 4 volts or better).

Batteries below 4 volts could experience thermal runaway or reversed cells (reduced
power storage capability).

To get around this, try disconnecting batteries and let sit to recover. They may build
to over 4 volts allowing charging.

Must be deep cycled after return to base.

APU/External Power Switch -- can have ON before/during APU start.

APU generator brought online automatically at 95% + 4 sec.

Will automatically takeover from External AC/DC Power source (it has priority).

Both batteries must be in aircraft and physically connected to start APU from External
DC Power (this is required to satisfy an interconnect -- batteries may be flat).

Battery switches must be OFF to utilize External DC Power.

External DC is locked out of the Battery Tie Bus when batteries are connected
(Battery Switches pushed IN) to prevent unconditioned charge of batteries by -
External DC Power.

When Battery Switches are pushed in -- only batteries power the Battery Tie Bus and
thus the auxillery hydraulic pump and APU starter motor even with External DC
Power connected and turned ON.

 Battery Switches -- OFF (takes Chargers & batteries off Essential DC Bus)
 TRU CB – PULL (Keeps from powering up TRU which has priority over
External DC during APU start. TRU will remove power
from the start circuit before APU generator power is
online, causing an APU shutdown)
 External DC Power -- Connect
 External AC Power -- Disconnect
 Auxiliary Power -- ON
 Do not pull Charger CB's (a G-III procedure).

See the full procedure in:

 AFM -- Abnormal Section 3-3

 Gulfstream/FlightSafety Pilot Abnormal/Emergency Procedures Checklist (Red

Book) Supplimental Procedures/Data Section, page S-9
Gulfstream IV Notes 5
Revision 2-98 Auxiliary Power Unit

Can apply both External AC Power and DC power simultaneously.

With External AC Power on aircraft, TRU will power all DC Bus's (has priority over
External DC Power).

To use External DC Power, pull TRU CB (PDB panel).

EXTERNAL AC POWER APU

The APU will NOT start using External AC Power with undercharged or flat batteries.

The only power available for start would be the two Chargers in TR Mode.

Chargers provide a combined 100 amps total of the 400 amps required.

Battery chargers will be ruined if a start is attempted under these conditions.

APU START WITH EXTERNAL AC & DC POWER

Starting the APU with External AC & DC power connected will blow Battery Chargers.

Disconnect External AC Power, start with External DC Power ONLY to be safe.

Cause of Charger Problems:

External AC power connects to and powers the battery chargers.

The APU starter switch connects the battery tie bus to the APU starter.

An additional circuit connects the external DC power to the battery tie bus for start assist.

Unconditioned external DC power flows through the battery tie bus to the battery
chargers and blows them.

Pulling the Battery Charger C/Bs will remove the problem, but there is no checklist
procedure for this.

See the “APU Start Using DC External Power” checklist in the red GAC/FSI Checklist,
page S-9.

APU AIRBORNE STARTS

Gulfstream IV Notes 6
Revision 2-98 Auxiliary Power Unit

APU start altitude: 15,000'

Speed: 250 KTS (no speed limit after start).

Note: During start tests between 15,000' and 20,000' the APU occasionally started on
first try, often started on second try and almost always started on third try.

APU ELECTRICAL OUTPUT

APU generator output:  100% (30 KVA) to 22,000'

 50% (15 KVA) at 30,000'

With a linear decrease between 22,000 -- 30,000'

Above 22,000’ the APU requires manual load shedding to maintain output below the
maximum allowable.

APU HIGH ALTITUDE MOD

ASC 96 (and SN 1156 & subs).

Incorporates a fixed scoop on APU air intake (no performance penalty incurred).

APU generator output: 30 KVA to FL 300 (100%)

15 KVA to FL 410 (50%)

With a linear decrease above FL 300.

Minimum electrical loading above FL 350: 10% (APU overspeed consideration).

Same start envelope as the original system: 15,000' max and 250 KIAS max.

The high altitude APU may run fast above FL 350 if electrical loading is light (below
10% load).

HIGH ALTITUDE INSPECTION REQUIREMENT

All APU flight time above FL 300 must be logged.

After one hour of operations above FL 300 or five operations above FL 300, a
combustion chamber inspection is required to inspect for coking.

ELECTRONIC LOAD WARNING SYSTEM (ELWS)

Gulfstream IV Notes 7
Revision 2-98 Auxiliary Power Unit

Provides auto load shedding.

An analog load meter with warning lights.

 W/S heat (one forward windshield and the opposite side window) is dropped
between FL 320 and FL 340.

 Galley power is lost if one converter fails.

Both will be reinstated automatically on descent through FL340.

ELWS Configuration Light -- Lights if one main converter is failed and the operating
converter is not hard selected.

Hard select the Main AC & DC Busses on the operating converter side to that
converter.

Hard select the Main AC & DC Busses on the non-operating converter side to the
APU/TRU position.

If the busses are not hard selected as described above, a failure of the remaining
main converter would shift the entire electrical load to the APU alternator flaming
out the APU.

ELWS Test System

The test switch is a push - ON, push - OFF latching switch.

If left latched on, false fail messages such as "Brake Fail" may result.

APU FIRE EXTINGUISHER

If inadvertently fired with APU OFF: no clean-up inspection required.

If inadvertently fired with APU ON: Inspection required because of thermal shock.

APU DOOR

There have been two failures related to the APU air inlet door.

1. The door actuator.

2. The door open switch.
Gulfstream IV Notes 8
Revision 2-98 Auxiliary Power Unit

Both failures will keep the APU from starting.

Improper Shutdown Procedures Cause APU Alternator Malfunction

A GII operator recently experienced difficulty getting his aircraft’s Auxiliary Power Unit (APU)
alternator to come on line. Troubleshooting revealed that there was a substantial amount of water
in the APU compartment, and the alternator was covered with moisture after a night of heavy
rains. Technicians removed the water, dried the alternator using an air drier, and left the APU
compartment panels open overnight. The following morning the APU started normally, and the
APU alternator came on line without further difficulty.

While debriefing the crew, maintenance technicians discovered that the crew had selected the
main battery switches “off” immediately after turning the APU master switch “off.” With this
procedure, the APU inlet door does not have sufficient time to fully close. Although some
operators use this shutdown procedure in an attempt to provide better APU cooling, Gulfstream
does not recommend it.

By ensuring all exterior access panels and doors are fully closed before securing the aircraft,
crews may avoid the opportunity for foreign object debris (FOD) ingestion leading to possible
flight delays.
(GAC Breakfast Minutes – 5/5/98)

More on APU Door Closing

The May 5, 1998 Breakfast Minutes contained an article about a GII crew selecting the main
battery switches off immediately after turning the APU master switch off. Some operators use this
procedure, attempting to provide better APU cooling. This procedure is not recommended by
Gulfstream because it does not allow the APU inlet door time to fully close.
An operator read the article and submitted the following question. “I know that turning the
APU master switch off after the batteries were turned off would leave the APU air door open.
However, since the APU master was in the off position, wouldn't closing the cabin door, when
securing the aircraft, close the APU door while the battery power was on? Would there be a
difference in this operation for GII, GIII, GIV, or GV crews?”

Technical Operations supplies the following answer. “On the GII, GIII, and GIV, the APU door
will finish closing when the Essential DC Bus is powered when closing the main cabin door. On
the GV aircraft, the APU door is controlled by the APU ECU. The ECU performs a controlled
shutdown of the APU to allow the unit to cool down. During this two-minute period, the APU door
closes in increments and is completely closed by the time the APU RPM is 5%. Should the
cooldown phase be bypassed by deselecting the APU Master, there is a possibility that the APU
may be damaged from heat build-up, even though the APU door will not close. For this reason, it
is best to follow the shutdown procedures in the manual and allow the ECU to perform its task.”
(GAC Breakfast Minutes – 5/19/98)
Gulfstream IV Notes 1
Revision 2-98 Powerplant

7. POWERPLANT
GENERAL
HP turbine -- 12,484 RPM at 100%
LP turbine -- 8,393 RPM at 100%

EPR ratio -- derived from ratio of duct pressure (rakes) to static pressure (DADC).

GIV max thrust guaranteed up to 30o C (G-III up to 22o C).

Advantage of EPR over LP RPM -- better actual indication of thrust.

The relationship of EPR to thrust with change in altitude.

At a fixed altitude: Increased EPR = Increased Thrust.

With an increase in altitude -- EPR increases and thrust decreases.

Static air pressure decreases faster than ram air (duct) pressure.

Each engine consumes 400 lbs of air per second.

300 lbs/sec thru bypass duct and 100 lbs/sec thru core (about twice the flow of a
Spey).

Air leaves the compressor at 238 PSI – the point of highest pressure.

1.70 EPR = 13,850 pounds of thrust at sea level (238 PSI @ P3 station at sea level)

FLIGHT IDLE SYSTEM

(Formerly called the Dual Datum System).

Engine high idle (or flight idle) is set at 67% HP RPM when flaps are greater than 22o
and altitude below 15,000'.

Idle drops to 47% HP RPM with the Nutcracker in the ground mode or with wheel
spin-up.
Gulfstream IV Notes 2
Revision 2-98 Powerplant

Because flight idle is not maintained with flaps less than 22 degrees, to make a flaps
20 or less approach, the pilot must manually maintain a minimum 67% HP flight idle
during an approach to have rapid acceleration capability.

For landing with Igniters ON, Cowl Anti-Ice is no longer required.

(AFM Revision A or B, 15 Jan 91)

An engine’s minimum idle will automatically revert to 67% HP (high idle) if its own side
Main DC Bus fails.

This condition will remain regardless of flap setting, altitude, Nutcracker status
condition or wheel spin-up.

FLIGHT IDLE LIGHT

The Flight Idle Light on the center post will be ON when an engine is restricted to flight
idle when it is not supposed to be.

Own side Main DC Bus failure above 15,000' or on the ground (WOW).
No power to the Flight Idle Solenoid -- fail-safes to Flight Idle.

The Flight Idle Light will also be ON when conditions call for the flight idle restriction
but the engines are not so restricted.

Landing with a Nutcracker failure to the airborne mode.

On touchdown, wheel spin-up will override the flight idle mode causing the
engines to go to ground idle. The Flight Idle System thinks it is still airborne
below 15,000', with flaps greater than 22o and the flight idle lights will come on.

GROUND IDLE

47 - 48% HP RPM

46.6% HP RPM min idle.

High Elevation Considerations: Engine idle may be lower at high elevation fields.

If engine idle RPM drops below 46.6 % HP, one or both converters may drop off
line during ground operations.

Keep the APU running with Aux Switch ON to avoid electrical power loss, if a
converter drops off-line.
Gulfstream IV Notes 3
Revision 2-98 Powerplant

ENGINE PNEUMATICS

7th stage -- Provides the primary source of bleed air.

12th stage – Back up source of bleed air for pressurization and the primary source of
bleed air for the cowl and wing anti-ice.

ISOLATION VALVE

Manual Opening -- Can be opened physically with a screwdriver or allen wrench.

 Must be closed for takeoff

 Must be open for starting left engine using the APU
 Must be open for starting right engine using External Air.

On ground with APU and engine bleed air switches ON:

 If engine power levers are advanced, APU Bleed Air SOV is closed (function of
power lever angle)
 Opens again when throttles closed.

No "SVO" Annunciation:

 Check air pressure (ie: APU air ON or External air on).

 If ok then assume Starter Valve stuck closed.

Possible to open manually -- access door on right side of each engine (¼" socket
wrench drive).

Not a geared valve -- 180 turn to open/close.

Exercise valve manually to loosen up -- then try a normal start.

If the valve must be held open, it must be closed at 40% LP RPM.

To signal 40%, use a visual signal such as raising speed brakes.

HIGH PRESSURE SECTION

N2 All Speed Governor -- 47% - 99.7%

Gulfstream IV Notes 4
Revision 2-98 Powerplant

Hydro-mechanical -- not electrical.

Maintains selected HP RPM.

LOW PRESSURE SECTION

LP turbine limited to 95.5%

N1 Speed Governor -- enforces 95.5%

Tay LP Turbine Rub -- results in LP turbine rundown in less than 70 seconds.

There also may be some noise or squeaking from engine during run down.

SB 721195 resolves problem as part of mid-life engine package.

Contact Rolls-Royce rep for procedures to eliminate rub.

(GAC Breakfast Minutes -- approximately 04/09/91)

TURBINE GAS TEMPERATURE (TGT)

Determined by nine probes, all averaged.

Located between the HP & LP turbines.

Outputs to cockpit and Top Temp Control.

TOP TEMPERATURE CONTROL (TTC)

Top Temp Control limits TGT to 800o C to avoid overtemp.

Controlled by engine temp control push switches on overhead.

If can't make static power, try with TTC OFF.

If TGT varies above and below 800o cyclically may be TTC.

T/O TGT 800o C. max -- Limited by Temp Control.

Ground start TGT 700o C. maximum.

Temp Control will not work properly on engine start.
Gulfstream IV Notes 5
Revision 2-98 Powerplant

Does not protect engine during starts.

Tay 611-8 Top Temperature Control System Deletion

Removal of the top temperature control (TTC) amplifier and actuator was incorporated in GIV
production at aircraft 1320 and sub. Rolls-Royce Service Bulletin 73-1420 disables the TTC
actuator by replacing the adjuster at the TTC stops with a gagging bolt. GIV ASC 394 and Rolls-
Royce Service Bulletin 73-1421 delete the TTC amplifier.
(GAC Breakfast Minutes -- 02/3/98)

Top Temperature Control System Removal

ASC 394 – removes the left and right engine top temp control systems. This ASC must be
accomplished in conjunction with Rolls-Royce Service Bulletin Tay 73-1420 and Tay 73-1421.
Tay 611-8 engine operation without the top temp control system has been extensively analyzed
and functionally tested by Rolls-Royce. The testing has also been supported by service
experience on Fokker F-100 aircraft.

Removal of the top temp control system removes approximately 10 pounds of weight, reduces
pilot workload, and eliminates periodic operational checks of the system.

The ASC kit is approximately $792. Labor hours have not been determined yet.
(GAC Breakfast Minutes – 4/7/98)

THRUST LIMITER

Also called P3 Limiter.

Should hold to Rated EPR +.01.

Senses p3 pressure -- limits to 238 PSI.

Needed for power limiting in cold conditions.

Power output of engine limited by airframe, not engine.

ENGINE LIMITER SUMMARY

N2 -- All Speed Governor HP Spool 99.7% HP RPM

Top Temp Control TGT 800o

P3 limiter -- Thrust Limiter 14,000 lbs thrust

LP Shaft Limiter -- N1 Limiter 95.5% LP RPM

Gulfstream IV Notes 6
Revision 2-98 Powerplant

ENGINE EPR EXCEEDANCE

Questions have recently been raised by some operators concerning Exhaust Pressure Ratio
(EPR) exceedances. The question is whether or not there are any engine maintenance actions
required in the event of an EPR exceedance which are not coupled with an N1 (Low Pressure
Compressor), N2 (High Pressure Compressor) or Turbine Gas Temperature (TGT) exceedance.

No engine inspection or maintenance action is required per the Tay and Spey Maintenance
Manuals in the event of an EPR exceedance as long as N1, N2, or TGT did not exceed a limit.
The EPR ratings for the Tay and Spey engines were designed to allow for adequate engine
margins under all flight conditions with a fully deteriorated engine.

Subsequent performance of the GII/III/IV aircraft is based on these ratings. The throttle quadrant
was designed to be able to provide the EPR rating at all flight conditions and full throttle will
slightly overboost the engine above the EPR ratings. The GII/III/IV engine mounts were designed
for a 9G emergency landing condition (nine times the weight of the engine and nacelle together),
which far exceeds any forward or reverse thrust limits with overboost, so no inspections are
required. No airframe inspections are required in the event of an engine EPR exceedance per
Stress Engineering.

Gulfstream recommends that operators do not operate the engines above the EPR ratings. Per
the Tay and Spey Operating Instructions, "Significant improvements in engine life and reductions
in engine maintenance costs can be achieved by use of thrust levels less than the maximum
ratings and by using the recommended operating procedures."
(GAC Breakfast Minutes – 8/18/98)

IGNITERS

$3500

Two per engine.

LIMITATIONS

For airplanes SN 1000 through 1249 without ASC 304:

30 seconds -- ON / 30 seconds -- OFF (indefinitely)

5 minutes -- ON / 30 minutes OFF

For airplanes SN 1250 and subs and SN 1000 through 1249 with ASC 304:

There is no duty cycle time limitation for continuous (airstart) ignition. (AFM 5 Jan
96).

PLUG FAILURE
Gulfstream IV Notes 7
Revision 2-98 Powerplant

In the standard configuration, both igniters are on the same switch and both are used for
starts.

No indication when one fails -- "IGN" light shows switch position only.

Failed igniters may still put out cracking sound (shorting from side of igniter to can).

When two fail on one engine -- no start.

Inboard igniter on each engine is on fuselage side -- hard to replace.

The other igniter is outboard from fuselage -- easy to replace.

IGNITER MODIFICATION

ASC 151 to put outboard igniters on start switches so that normal ground starts will only
use them.

Both inboard and outboard igniters will be activated by Airstart Ignition switches.

If engine won't start due to a failed outboard igniter:

 Wait 3 minutes
 Dry crank
 Select Airstart Ignition Switch ON
 Do a normal start

Engine Torching -- Older engines may torch (flame out tailpipe) when started on one
igniter due to coking of burners and slower flame propagation.

Not known to harm aircraft.

Can avoid by using Airstart Ignition (two igniters) with ASC 151 modified
aircraft.

MEL will allow dispatch with one igniter inoperative (of four).

ASC 151 has not been too popular with operators due to torching.

Has been removed by some operators.

Still a production item on new SPs.

ENGINE MISCELLANEOUS
Gulfstream IV Notes 8
Revision 2-98 Powerplant

Inlet Guide Vanes -- variable pitch.

Set at 40o pitch up to 80% HP RPM.

Bleed Ring at 7th stage -- closes at 80% HP RPM.

OVERFUELING SYSTEM

Not related to the Flight Idle System (Dual Datum Idle).

To solve a compressor stalling problem at altitude adds fuel over that required for
normal engine acceleration in flight.

Compressor stalls tend to do severe damage to the Tay Engine.

At steady state power setting -- schedule normal.

When on ground or w/ Airstart Ignition ON -- overfueling disabled.

W/ Ignition ON -- you lose engine stall protection.

Not a problem for takeoff.

Could be a problem on landing go around.

To solve use Cowl Anti-Ice w/ Ignition

Reactivates overfueling system.

The use of Cowl Anti-ice with Ignition ON is no longer required or

recommended by GAC.

ENGINE FUEL FLOW EXTREMES

Fuel flow at idle = 600 lbs/hr

At full throttle = 6000 lbs/hr

ACCESSORY GEAR BOX (BANANA BOX)

Right hand gear box.

Driven by HP Spool.
Gulfstream IV Notes 9
Revision 2-98 Powerplant

ENGINE HOT

Internal cooling air is excessively hot.

Bleed air is routed internally through the engine area to cool it. This air is exhausted
through a mast located below each engine nacelle, two/thirds of the way back.

This cooling air temperature is sensed and will set off the “Engine Hot” annunciator if
it exceeds acceptable limits.

Indicates an internal problem -- most likely a bearing problem.

Secondary indications:  Oil temperature high

 Fuel temp high (cools oil)
 TGT high
 EVM high

There has never been a valid "ENGINE HOT" message on a GIV.

ENGINE OIL

Check oil quantity at same time relative to flight every time.

Always on post flight or always on preflight to get consistent readings.

Max allowable consumption -- 0.9 pints/hour.

OIL CONSUMPTION

Left Engine Oil Consumption within Limits

A GIV crew, new to the aircraft, reported that during preflight the left-hand (LH) engine oil was 4
pints low. They could see oil lying in the lower engine cowl by looking into the oil service access
door.

During troubleshooting, the technician wiped down the inside lower cowling, asked the pilot to
start the engine, and performed a leak check of the engine and accessories. Upon visual
inspection of the LH engine, no leaks were noted; the engine was found to be very clean. At idle a
small amount of oil was noted exiting the LP Cooling Air Outlet. As the engine power lever was
advanced and RPM increased, the exiting oil ceased.

During pilot debrief, it was determined the previous flight time was 8.0 hours. The oil level was 2
pints below full before departure. The aircraft had no past history of high oil usage. Oil level after
the flight was 4.1 pints below full.

The pilot was informed that the condition is normal at lower engine RPM and the acceptable leak
rate is 3 cc’s per minute. Oil consumption of 2.1 pints during an 8-hour flight was well within the
Gulfstream IV Notes 10
Revision 2-98 Powerplant

limit of .75 pints per hour and is also acceptable. The pilot found this explanation satisfactory and
returned the aircraft to service.
(GAC Breakfast Minutes – 6/9/98)

ENGINE SYNC

Right engine is master.

Must be OFF for takeoff and landing.

Turn OFF for major power changes.

Select HP or LP as required -- each aircraft responds differently.

EVM

Test level = 2.0

Write up when vibes reach:  1.25 LP

 0.6 HP

You can normally feel vibrations in airframe with EVM’s of 0.3 or greater.

EVM Test -- to be valid engines must be OFF.

Should check both primary & secondary vibration sensing systems.

Checks primary & secondary charge amplifiers.

Does not check accelerometer or tachometer inputs

GAC Interoffice Memo, B. Carter, Product Engineering, 09/12/90.

Primary Vibration Sensor -- between #3 & #4 engine bearings.

In the turbine area -- more susceptible to failure.

Secondary Vibration Sensor -- Between #1 & #2 engine bearings.

Picks up accessory gearbox problems including hydraulic pump as well as bearing

failures.

NEW DUAL ENGINE FLAMEOUT PROCEDURE

Gulfstream IV Notes 11
Revision 2-98 Powerplant

GAC OIS-4 Supplement to the AFM Released.

Deals with bird ingestion, volcanic ash, turbulence & rain encounters.

Enhanced restart procedures and dual engine out landing procedures.

Procedure: 300 KTS down to 25,000' and then 210 KTS below.

Gets A/C down to 25,000' fast.

Pax oxygen masks good below 25,000'.

ENGINE START

Max APU AC Load for Start -- 35% percent load is max for start.

Use 30% at a high altitude airports to reduce APU loading

(AFM change 04/94)

A load over 30% prior to start is normally caused by closing the main door.

Causes aux pump to come on taking Battery Chargers to the TRU mode.

When the Chargers come out of TRU mode, they switch to high charge while
sampling the condition of the batteries (lasts a few seconds).

To reduce the APU AC load for engine start:

1. Fuel Crossfeed -- open

2. One Main Boost Pump -- OFF

Don't use galley power (can screw up F/A's operations).

EXTERNAL AIR START PROCEDURE

Procedure can be found in the AFM Supplements.

25 PSI bleed air pressure is required to open the start valve.

15 PSI is required to keep it open and maintain start.

25 PSI will ensure a cool start.

Gulfstream IV Notes 12
Revision 2-98 Powerplant

External air is regulated down to 42 PSI at the ground air connection and cannot exceed
that value.

35 lbs./minute of airflow is required for the first 20 seconds of start.

BATTERY (OR EXTERNAL DC)/EXTERNAL AIR START PROCEDURE

In order to have engine parameters and CAS messages available, the DUs must be
selected on and the symbol generators must be switched to NORM/ALT/ALT. With the
SPZ-8400, the EICAS must additionally be selected to Top Compact.

This procedure is covered in the GAC/FSI Red Pilot Checklist, page E-40

BATTERY ONLY STARTS

The engines will accelerate to flight idle RPM (67% HP RPM) until the main busses are
powered with a converter selected on.

ENGINE START PROBLEMS

Air Conditioning SOV Failure Unmasked Following Transition to High OAT

Environment

A GIV flight crew asked us, "What would be the normal time limit for the Tay engine to start, or
reach a positive Low Pressure (LP) rotation?" The question originated following crew
observations of an increase in time to start the right engine. The crew members were informed
that there is not a published time frame for start or positive LP rotation, but time to start had to
remain inside the starter duty cycle. Maintenance technicians performed ground runs with no
discrepancies noted.

The aircraft later departed on an extensive trip to areas where the ambient temperatures were
higher then recently visited locations. The Bleed Air Manifold (BAM) pressure was noted to drop
to 12-14 psi during engine start. A leak check was performed of the equipment room BAM with no
discrepancies noted. On an Auxiliary Power Unit (APU) run data sheet, the crew had noted a
higher than normal APU Exhaust Gas Temperature (EGT) with a blocked manifold. EGT were
anywhere from 120-150°C higher then normal, indicating a leak in the bleed air manifold. The
crew elected to continue their trip and monitor the system. During an engine start prior to
departure from Phoenix, Arizona, where Outside Air Temperature (OAT) was recorded at 45°C,
the BAM pressure dropped to approximately zero psi. The starts were aborted and a ground air
start cart utilized to meet the scheduled itinerary.

Upon arrival at their next destination further troubleshooting revealed the right air conditioning
shut off and flow control valve was not closing sufficiently. A replacement valve was coordinated
to arrive at the operator’s next destination, where it was installed and subsequent operational
checks returned the system to service.
Gulfstream IV Notes 13
Revision 2-98 Powerplant

As the aircraft had been operating in areas where the OAT were quite low, the BAM pressure was
adequate due to the air density and masked the failed component. Upon transiting to areas with
higher OAT and a thinner air density, the problem became more prevalent.
(GAC Breakfast Minutes – 8/18/98)

BUDDY STARTS

Q – Regarding the airstart for the GIV and GV. The donor aircraft, as mentioned in Service News
97-3 (July-August-September); is there a particular reason the GIV and GV are not allowed to be
donor aircraft, whereas the GII and GIII are permitted to be?

A – The GIV and GV are each built with an extra check valve that is installed upstream of the
ground air connection, which will not allow the airflow backwards for the buddy start capability.
With a buddy start from a GII to a GIV or from a GIII to a GV, when you connect the special hose
to the GII or the GIII, you actually open the check valve that is at the airstart connection, allowing
the air to flow backwards. The extra check valve on a GIV or GV does not allow for that. At
present, there is no way of opening the second check valve because it is farther up the line and
cannot be reached to open manually. (Reference Service News 97-3.)

Q – By my calculations, you are going to have 380 to 400 GIVs by the end of this year and 100
GVs by the end of next year. You only have 450 GIIs and GIIIs and most of those do not go
overseas. What will you do for emergency starts from donor aircraft when the GIIs and GIIIs are
not around?

A – Gulfstream has taken this item under consideration. Engineering has been assigned the task
of developing a modification to allow the GIV and GV aircraft to be donor aircraft. If modification is
deemed feasible, we will announce design completion and parts availability.
(GAC Breakfast Minutes – 11/11/97)

FORWARD LAVATORY FOD PROBLEM

Fluid leaking from the forward lavatory drain is drawn up into the engine intakes.

Newer installations have the service panel mounted lower on the fuselage to avoid this
problem.

ENGINE COLD START PROCEDURE

The cold start procedure contained in AFM Appendix E, Adverse Weather

Conditions/Abnormal Atmospheric Conditions must be used when the OAT is below -10
C (+14 degrees Fahrenheit) per the AFM Normal Section.
Gulfstream IV Notes 14
Revision 2-98 Powerplant

ENGINE SHUTDOWN WITHOUT APU RUNNING

Hard select Essential DC Bus to Battery.

Maintains power on the Essential DC Bus (and thus to the standby generator shutoff
valve solenoid). Otherwise, the Essential DC Bus goes from Left Main DC Bus to
Right Main DC Bus to battery source in search of power as the alternators go off line.

Failure to hard select the Essential DC Bus to Batt will cause the Standby Electrical
Power System pump to run up with loud "brappp".

Leave the converter power switches ON until the Fuel Shutoff Valves are closed. The
engines will attempt to accelerate to Flight Idle (67% HP RPM) if the converters are
selected off normally with no APU generated AC power on Main AC Busses.

Once the Fuel Shutoff Valves are closed, the converter switches may be selected off.

ENGINE NACELLES

SECURE UPPER ENGINE COWLING WHEN A/C IS OUTSIDE THE HANGAR

Recently, a GIV operator reported that following aircraft maintenance within the hangar, the
maintenance crew pulled the aircraft out with the lower cowling open, in order to perform engine
runs as part of a scheduled maintenance inspection for engine oil leaks. A gust of wind caught
the upper cowling, ripped it loose from the back hinge, twisted the forward hinge, and flipped it up
on the dorsal fin. The cowling incurred quite a bit of damage and the dorsal fin also sustained
minor damage. This operator was caught off guard, by not realizing that high winds can pick up
the upper cowling, even though it is closed.

A GIII international operator was not as lucky. As he pulled the airplane out of the hangar, a 60-
knot wind caught the cowling, taking it off completely over the top of the airplane, and damaging
the wing leading edge on the other side.

We recommend that you secure the cowling on your aircraft when it is outside the hangar. If you
must have the lower cowling open, secure the top cowling. Many operators use the ½-inch wide,
24-inch ty-wraps. Other operators use belts.
(GAC Breakfast Minutes -- 01/27/98)

ENGINE COWLING SAFETY

In the January 27, 1998 issue of the Breakfast Minutes, Mark Thibault cautioned operators to
"secure upper engine cowling when aircraft is outside of the hangar." The article concerned
securing the upper engine cowl during outside maintenance. There has been an increase in the
upper cowls being blown open by a gust of wind since that writing. Usually, when this happens
the cowling, fixed cowl, and airframe incurs damage. A pubs change has been submitted to
incorporate the following Warnings and Caution in the maintenance manual Engine Cowling
Open and Close procedures.
Gulfstream IV Notes 15
Revision 2-98 Powerplant

• WARNING: Do not open engine cowl doors when the wind speed or gusts is 60 MPH (96
KM/H) or more. An injury and/or damage can occur if the wind moves the cowl doors.

• WARNING: Be careful if you open the engine cowl doors when the wind speed or gusts is 30
MPH (48 KM/H) or more. An injury and/or damage can occur if the wind moves the cowl doors.

• WARNING: Any time when working on the flight line with the lower engine cowl door open,
ensure that the upper cowl door is secured either with upper cowl jury strut or a fiberglass multi-
strand strap. An injury and/or damage can occur if the wind moves the cowl doors.

• WARNING: Do not operate the engine with the cowl doors open and safetied by the hold
open rods at power levels higher than idle. An injury and/or damage can occur if you do not obey
this instruction.

• CAUTION: If upper cowl is not opened and secured by jury strut, the upper cowl must be
secured in some way to keep it from being blown open.

• CAUTION: To prevent possible damage to upper cowl door and/or fuselage, secure upper
cowl while lower cowl is open. Do not use bungee cord for this procedure.
(GAC Breakfast Minutes – 03/10/98)
Gulfstream IV Notes 1
Revision 2-98 Fire Protection

8. FIRE PROTECTION
FIRE DETECTION

FIRE HANDLE

Pulling fire handle shuts OFF:

 Hydraulic SOV
 Fuel SOV
 Thrust Reverser on affected side
 AC Converter

VALID FIRE INDICATION

A fire indication may be considered valid if the "ENG FIRE LOOP ALRT" annunciator
is displayed and a Fire Handle and/or HP Cock light is illuminated.

The Fire Handle and HP Cock lights are in parallel.

The HP Cock light is susceptible to failure (bulbs fall out).

Fuel Cock/Fire Handle Illumination – Both Loops A and B must be activated to

illuminate.

Master Warning/Triple Tone/CAS Message – Activation of either Loop A or B is

sufficient to illuminate these.

Test system after completing procedures to ensure integrity of fire loop.

"ENG FIRE LOOP ALRT" -- overheat/fire external to the engine casing.

"L-R ENGINE HOT" -- overheat internal to engine casing.

Fire Indication Extinguishes Power Lever Retarded – Suspect a bleed air leak as the
source of the fire warning.

INVALID FIRE INDICATION

"ENG FIRE LOOP ALRT but NO Fire Handle or HP Cock light and only one Loop light
segment lights on the Fire Test push switch.
Gulfstream IV Notes 2
Revision 2-98 Fire Protection

Suspect a bad Fire Loop (false alarm).

Do a fire test -- if unlighted loop segment lights, test is good and no fire.

Push out (deselect) faulted (lit) loop to reactivate the system on the remaining loop.

CONTAMINATED CONNECTORS CAUSE ERRONEOUS ENGINE FIRE

INDICATION

A GIV crew aborted a takeoff due to an amber fire loop message. After clearing the runway, the
crew complied with the Minimum Equipment List, and the faulty engine fire loop (left engine Loop
B) was turned off. The crew determined it was safe to continue the trip with Loop B deselected.

During descent, the crew experienced a left engine fire loop alert and warning tone. Nine of the
ten warnings where present (Loop B was turned off). The crew selected the engine fire check list
and discharged both fire bottles; however, the left fire handle was still illuminated. The pilot made
a clearing turn to the left to visually check for smoke. No smoke was evident. The crew declared
an emergency and made an uneventful single-engine landing. Fire crews met the airplane on the
runway and determined there was no evidence of an engine fire.

During troubleshooting of the fire detection system, technicians discovered that both fire warning
element connectors that go through the fixed cowl had been incorrectly installed, allowing for
water and contaminant intrusion. This caused a high-resistance short to develop, followed by an
erroneous fire warning indication.

It is suggested that during a pylon internal inspection you check the fire warning element
connectors for proper installation and integrity.

(GAC Breakfast Minutes – 06/10/97)

SMOKE DETECT AND FLAME DETECT CAS WARNINGS CANNOT BE

INHIBITED

A GIV operator recently discovered that the SMOKE DETECT and FLAME DETECT Crew
Advisory System message warning tone (3-bong alert) would not inhibit when either the pilot’s or
copilot’s inhibit switch was pressed and the systems were tested or activated. The operator talked
with Gulfstream and Honeywell personnel and determined that Honeywell makes no reference to
being able to inhibit the audible warning for smoke or flame detection.

The GIV Airplane Flight Manual, Systems Page 5-42,1000-1300. by Paul Lu, Technical
Operations GIV - Dorne & Margolin ELT Remote Switch Update states the Smoke Detect and
Flame Detect warning tones/lights can be inhibited (1000-1252 except 1236). A publications
change has been submitted to add these two annunciations to the list of messages that cannot be
inhibited.
(GAC Breakfast Minutes – 01/01/97)
Gulfstream IV Notes 1
Revision 2-98 Pneumatics

9. PNEUMATICS
ENGINE BLEED SYSTEM
The Bleed Air Switch controls three valves.

 7th Stage Valve

 12th Stage Valve
 Bleed Air Precooler Valve

All three valves are automatically controlled open or closed once the Bleed Air Valve is
selected ON.

7TH STAGE AIR

Normally used for T/O, climb and cruise.

Bleed Air Pressure Regulator and Shutoff Valves will close with power removed
from valve (Essential DC Bus).

Expect a loss of pressurization with a Essential DC Bus failure.(unless ASC 359

complied with.

ASC 359 repositions the right Bleed Air Bus SOV control power source to the Right
Main DC Bus.

No production cut in.

Regulates pressure to 40 PSI or as available below 40 PSI.

40 PSI is the most you would normally expect to see.

Normally will see 21-25 PSI at altitude in cruise flight.

12TH STAGE AIR

12th Stage Air SOV will open automatically if:

 The opposite pack selected OFF (based on switch position)

 Cowl or Wing A/I selected ON (for extra heat)
 During descent or if manifold pressure drops below 18 PSI.
Gulfstream IV Notes 2
Revision 2-98 Pneumatics

Any time manifold pressure is below 18 PSI, 12th stage valve is open.

Will close with power removed from valve (Essential DC Bus).

Regulates pressure to 30 PSI, or max available below 30 PSI, with Anti-Ice OFF.

Regulates temperature to 575 F. With Anti-Ice selected ON (pressure will normally

rise above 30 PSI, if available, to maintain 575 F.).

Bleed air passes through an air-to-air Precooler in the pylon (the vent opening below the
pylon) cooling the bleed air to about 400 F.

In normal cruise with two bleed airs & two packs - ON, and Anti-Ice OFF:

Would expect to see 21-25 PSI in each manifold

If selected one pack switch OFF with the isolation valve closed, manifold pressure on
that side would rise to 40 PSI (nominal 7th stage regulated pressure due to no demand).

Manifold pressure on side with operating pack would rise to 30 PSI (12th stage air
valve open and regulating to 30 PSI).

An indication of 23 PSI would be sufficient to maintain pressurization but would be

considered abnormal and might indicate a problem.

BLEED AIR PRECOOLER

The Fan Air Modulating Valve modulates fan air to precool engine bleed air (5700 F to
4000 F).

Requires both air pressure and electrical energy to close.

The modulating valve fails to the open position (full cooling) with power removed
(Bleed Air SOV Switch in Off position or failed power source).

DUAL PACK OPERATIONS

If 7th stage air > 18 PSI -- no 12th stage air used.

If 7th stage air < 18 PSI -- 12th stage provides at 18 PSI.

In cruise flight, normal manifold pressure 25 PSI.

7th stage regulator (shutoff) valve tries to maintain 40 PSI.

Gulfstream IV Notes 3
Revision 2-98 Pneumatics

12th stage tries to maintain 18 PSI if 7th stage drops below 18 PSI.

Need 15-16 PSI to pressurize door seals -- will depressurize if below 15 PSI and
check valve fails.

ASC 313: Both bleed air manifolds regulated to 30 PSI when power levers are retarded
below 600 PLA.

Provides sufficient bleed air pressure during low power descents to maintain cabin
pressurization without an initial pressure dip.

SINGLE PACK OPERATIONS

If 7th stage air is > than 30 PSI, no 12th stage bleed air.

If 7th stage air is < than 30 PSI, the 12th stage regulator will open and try to maintain 30
PSI.

Engines must have a pack or Cowl Anti-Ice ON above 41,000' to protect against surges &
stalls.

If must turn OFF a pack above 41,000' must turn ON Cowl Anti-Ice or descend to or
below 41,000'.

If forced to turn OFF a bleed valve above 41,000', effective Cowl Anti-Ice is not
available (open isolation valve to regain pack).

Must descend to 41,000' or below.

BLEED AIR VALVES

Left and right valves controlled by Left and RIGHT BLEED AIR CB's (Essential DC
Bus).

A pulled or popped CB removes power to the respective bleed air valve causing it to
close.

Failure of Essential DC Bus power will also close both valves (removing
pressurization) unless ASC 359 is installed.

ASC 359: Right Bleed Air Bus Change

PURPOSE: Presently the left and right Bleed Air systems and the left and right Air
Conditioning systems are powered from the Essential 28VDC bus. This
ASC will relocate the right Bleed Air, right Bleed Air Indicator and the
Gulfstream IV Notes 4
Revision 2-98 Pneumatics

right Air Conditioning circuit breakers from the Essential 28 VDC bus to
the right Main 28 VDC bus. This change will provide 28 VDC power for
cabin pressurization from either the right Main 28 VDC bus or the
Essential 28 VDC bus.

The right bleed air CB also provides control power to the isolation valve. (See Isolation
Valve on page 9-4 & 9-5).

BLEED AIR MALFUNCTIONS

HIGH BLEED PRESSURE

Amber "L/R BLEED PRES HI" EICAS message.

Manifold pressure 75+ PSI (normal max pressure 40 PSI).

Shut OFF bleed air valve.

Descend to FL 410 or below w/o engine bleed source.

Prevents compressor stalls on rapid engine accelerate/decelerate.

Compressor stalls do serious damage to Rolls-Royce engines.

BLEED AIR MALFUNCTION PROCEDURES

Red CAS Messages: Common Procedure

"AFT EQUIP HOT"  Bleed Air -- OFF

- or -  Isolation Valve -- CLOSED
"PYLON HOT"  FL 410 or below
 Isolation Valve -- MAINTAINED CLOSED

Amber CAS Messages:

"BLEED AIR HOT"  Bleed Air -- OFF

- or -  Isolation Valve -- CLOSED
"BLEED PRESSURE HI"  FL 410 or below
 Isolation Valve -- OPEN

Note: It is easier to confirm the Isolation Valve closed after one Bleed Air Valve is
closed. Note the pressure differential indication on the Manifold Pressure gauges.
Gulfstream IV Notes 5
Revision 2-98 Pneumatics

Pylon Hot -- With the Bleed Air Valve shut, it is still possible to get a Pylon Hot
annunciation.

A portion of the 12th Stage plumbing passes through the pylon area before reaching
the 12th Stage SOV. A leak in this section will continue to light the Pylon Hot
annunciation until the effected engine is powered back or shut down.

LOW BLEED PRESSURE DURING DESCENT

If one side reads 18 PSI and the other reads significantly less, the 12th stage valve has not
opened on the low side.

May force it open by selecting Cowl A/I ON failed side.

ISOLATION VALVE

A motorized valve -- will fail to current position with power removed.

When the Isolation Valve loses Essential AC electrical power, it fails to its current
position (normally closed) but shows a barber pole on the Isolation Valve Switch in the
overhead panel and "ISOLATION VALVE OPEN" on the CAS annunciator regardless of
the actual valve position.

If isolation valve won't open for start:

 Cycle CB on pilot's overhead panel (lower right)

 Isolation Valve Control CB -- "R BLEED AIR"

The Isolation Valve will motor closed (if open) and “ISOL VALVE OPEN”
annunciates.

The Isolation Valve shares this CB with the Right Bleed Air SOV.

Isolation Valve Power CB -- "BLEED AIR ISO S/O V".

If that doesn't fix the problem:

 Leave "R BLEED AIR" CB out.

 Take slotted screwdriver (or allen wrench) to rear equipment bay, open the cap on
the isolation valve and turn counterclockwise (9 + revolutions).

 Start engine and manually close Isolation Valve.

Gulfstream IV Notes 6
Revision 2-98 Pneumatics

Note: Right bleed air CB controls both the Right bleed air valve and the isolation valve.

A pulled or popped Right bleed air CB will freeze the isolation valve in its current
position (normally closed).

The isolation switch "White Bar" comes on.

A false EICAS message "ISOL VALVE OPEN" will appear.

ASC 298 prevents false message display (SN 1202 & subs).

ASC 298 Modifies Bleed Air Isolation Valve Power Source

A problem with the isolation shutoff valve indicating open when it is actually closed first
appeared in 1991. A defective 40 PSI valve on the subject aircraft had popped the right
bleed air circuit breaker. The isolation shutoff valve indication logic is controlled through
the right bleed air circuit breaker. When the C/B pops, a relay relaxes and annunciates the
isolation valve as being open.

As a result of this condition, Aircraft Service Change 298 was developed to add an AC
valve control relay. This precludes de-energizing of the relay and a false cockpit
indication of valve position.

During a recent trip to the Middle East, the crew of a GIV without ASC 298 could not start the left
engine. Although the bleed air isolation valve indicated open, it was closed. They depressed the
right bleed circuit breaker and it stayed in long enough for the crew to open the isolation valve
and start the left engine. The CB was then pulled in the event the electrical failure recurred. The
aircraft returned to home base without further incident. Upon the aircraft’s return to home base,
the area Field Service Rep helped troubleshoot the problem as a defective bleed air valve, and
one was ordered. However, further investigation revealed that unless the aircraft has ASC 298
installed, the isolation valve cannot be opened from the cockpit if the right bleed air C/B is open.
The isolation valve must be manually opened in the tail compartment.
The production cut-in of ASC 298 was aircraft 1202 and subsequent. If your aircraft does not
have ASC 298, you should consider having it installed.
(GAC Breakfast Minutes – 03/03/97)

To Check If the Isolation Valve Is Closed

 Check manifold pressures

 Increase one power lever -- look for pressure increase in one side only.

Isolation Valve Stuck Open on Ground

Check:  Start master switch -- OFF

 Crank master switch -- OFF
 APU air switch -- OFF
 Isolation valve switch – CLOSED
Gulfstream IV Notes 7
Revision 2-98 Pneumatics

Broken Isolation Valve Switch

If the isolation valve switch is broken may open isolation valve by selecting APU air
switch - on.

Automatically opens isolation valve.

Will open isolation valve in flight in spite of nutcracker lockout of airborne APU
bleed air.

Start & crank master switches will not open the isolation valve airborne.

MAIN DOOR SEALS

Inflatable seals

15-16 PSI to inflate

If seal blown, cabin differential will reduce to zero in 30 seconds.

BAGGAGE DOOR SEALS

Inflatable seals.

If deflated, should be able to maintain cabin pressure w/ 35 PSI of manifold pressure.

If cabin pressure falls with power reduction, suspect door seals.

Possible leaking seal.

May be bad check valves in door seal system allowing seals to deflate when system
pressure is less than 19 PSI.

Engine Bleed Air pressure may be increased by selecting one of the Pack Switches --
OFF.

Selecting a Pack Switch off forces the opposite side 12th Stage Bleed Valve to open,
increasing airflow and possibly compensating for seal leak.

The opposite side 12th Stage Bleed Valve opens as a function of Pack Switch
position, regardless of the status of the controlled pack.
Gulfstream IV Notes 8
Revision 2-98 Pneumatics

With one engine shutdown, selecting the dead engine's own side pack switch -- OFF
will force the operating engine's 12th Stage Bleed Air Valve open, increasing
flow (and increasing load on the engine).

ASC 364 -- 12TH Bleed Air Source for Door Seal System

Improves the Cabin and Baggage door seal performance and reliability by providing
increased air pressure.
Gulfstream IV Notes 9
Revision 2-98 Pneumatics
Gulfstream IV Notes 1
Revision 2-98 Ice and Rain Protection

10. ICE AND RAIN PROTECTION

COWL ANTI-ICE
Sends 570o C air to cowls.

Engines de-ice themselves by throwing ice off spinner.

Cowl Anti-Ice just keeps hole open.

Minimum required pressure -- 4 PSI (was 16, then 10 PSI).

Blue "COWL ANTI-ICE" EICAS message indicates switch position only.

Red "COWL ANTI-ICE" EICAS message indicates pressure below 10 PSI (ASC 243
sets EICAS message to below 4 PSI).

If, when Cowl Anti-Ice is activated, you get an increase in TGT and a drop in HP RPM --
Compressor Stalls are occurring.

Try retarding throttle slowly.

Requirement has been eliminated in AFM to use Cowl Anti-Ice with igniters on landing.

Cowl Anti-Ice draws about as much air as a pack.

Crossbleed Cowl Anti-Ice -- Can use Cowl Anti-Ice from opposite engine with isolation
valve open and on-side bleed air valve closed.

Not too effective since bleed air must pass thru own side Precooler and opposite side
(full open) Precooler before being routed to opposite engine.

Most of heat is removed.

Maximum OAT For Use of Cowl Anti-ice -- There is no maximum OAT for use of
Cowl or Wing Anti-Ice (will not cause heat damage to any structure).

Engine Vibration with Icing

Expect an increase in engine EVM's with fan icing.

Cowl anti-icing does not prevent fan icing

Prime fan icing conditions:

Gulfstream IV Notes 2
Revision 2-98 Ice and Rain Protection

 OAT/SAT less than 8o C

 Visible moisture
 Low power settings for long times
 Cowl Anti-Ice ON or OFF

Start Up In Icing Conditions -- Let vibrations go to idle or 0.6 EVM.

Ice should shed.

Ground Operations -- GAC recommends Cowl Anti-Ice ON for all ground operations
under the above conditions.

To shed ice build up:

 Set 85% LP RPM for one minute

 If LP EVM approaches 0.60 IPS, GAC recommends engine shutdown.

In this case, de-ice using hot air or hangar aircraft.

Use of chemical deicers to de-ice the engine inlets is not recommended due to warranty and
life shortening considerations
(GAC Breakfast Minutes -- 02/01/94)

PROCEDURE FOR INOPERABLE ANTI-ICE VALVE LOCATED IN MOPS

During a trip, a GIV crew noted that the right engine anti-ice valve was popping the circuit
breaker. Consulting the minimum equipment list (MEL) the crew discovered they could dispatch
the airplane with the valve locked in the “open” position. Not finding a procedure for this action in
the master minimum equipment list (MMEL), flight manual, or the maintenance manual, they
elected to lock the valve open and continue the trip. When the crew attempted to start the engine,
the required high pressure (HP) rotation could not be achieved because the APU cannot supply
the volume of air required for engine start with the anti-ice valve open. After consulting with their
maintenance department, the crew closed the valve, started the engine, then locked the valve
open for dispatch to home base.

The procedure to start and dispatch with one anti-ice valve inoperative is located in GIV AFM,
Appendix C. The procedure states: “Start the engine with the operating valve first and maintain
30 psi in the manifold to supply the required volume of air for engine start.” We would like
to remind our operators that the MOPs contains a great deal of information on aircraft operation.
We recommend that it become a standard part of your trip kit.
(GAC Breakfast Minutes – 11/18/98)

The Maintenance, Operational, Placarding, Procedures (MOPs) Manual, Section 30, Item 9
references the Airplane Flight Manual (AFM) procedure.

We have submitted a publication change request to add a procedure on how to lock the valve
open, along with incorporation of an illustration of the valve’s locking device. This should be
incorporated in the near future.
Gulfstream IV Notes 3
Revision 2-98 Ice and Rain Protection

As stated previously, the MOPs contains a great deal of information on aircraft operation. We
recommend that it become a standard part of your trip kit along with the AFM and your Minimum
Equipment List (MEL). Please note that an individual operator must go through an FAA process
to take the Master Minimum Equipment List (MMEL) and Gulfstream MOPs manual and tailor
them into his aircraft’s MEL and MOP. As with the MMEL, the MOP will not be official until the
operator gets a letter of authorization from the governing Flight Standards District Office (FSDO)
to use our document. Please contact your FSDO for more information.
(GAC Breakfast Minutes – (12/02/97 )

WING ANTI-ICE
Sends 400 C air into leading edges.

Blue "WING A/I ON" EICAS message indicates switch position only.

Overhead green "WING WARM" light based on 100o F switch -- positive indication.

System tries to maintain 100-135o F.

For use before entering possible icing conditions.

"L-R WING TEMP LOW” -- Amber Message on newer GIV's.

Senses exhaust air from wings below 100O F. after 2 minutes from heat selection.

Shows on the CAS as a more effective attention getter.

ANTI-ICING USING APU BLEED AIR

If APU air is used on the ground to test Anti-Ice, the load control valve may not be able
to reduce pressure before EGT overtemps.

Garrett recommends against procedure.

Use engine bleeds only

GAC GIV Coordination Memo from Bruce Crawford.

WINDSHIELD HEAT
W/S Heat Power Sources
Gulfstream IV Notes 4
Revision 2-98 Ice and Rain Protection

 Left front/right side powered by L Main AC Bus

 Right front/left side powered by R Main AC Bus

Not required for BIRD PROTECTION

Windshield Heater Latching

If on during bus change, systems with the “Dash One” controller can malfunction and
cause windshield heat to latch off or go to full hot setting.

Aircraft upgraded to the "Dash Three" controller can still Latch Off but won't overheat.

Latch Off can occur after a(n): Converter failure

 Engine shutdown/failure
 Engine start
 Any bus change

Cure: turn OFF windshield heat for 10 sec and then ON

Prevention: wait until converters are on line before turning W/S heat ON and turn
W/S heat OFF as part of after landing checklist.

Note: Windshield reset should be the last item on an engine shutdown and converter
failure checklist.

PITOT HEAT

In first 150 GIV's with:  Essential AC Bus dead

 Essential DC Bus powered
 Pitot Heat switch -- ON

Left Pitot Heat says OFF but is ON.

DE-ICING

Tail De-Icing -- the tail (including the top of the horizontal stabilizer) must be de-iced
even though the aircraft is certified without tail anti-icing equipment.

After tail de-ice:  Check trim full up & down

 Visually check tail trim position. (Shear rivet in drive shaft could
break).

One GIV operator deiced wings covered with snow and ice. They did not de-ice the
horizontal stabilizer. Climbing thru 17,000' they ran out of nosedown trim at 290 KTS.
Gulfstream IV Notes 5
Revision 2-98 Ice and Rain Protection

They leveled at FL 220 and could maintain 290 KTS with 6 degrees nose down trim. On
descent into warmer conditions, the problem resolved itself.
FSI student feedback 01/21/91

Note: if a miss-trim indication is received, grab controls firmly before releasing autopilot
Gulfstream IV Notes 1
Revision 2-98 Air Conditioning

11. AIR CONDITIONING

New outflow grills allow engine start without one pack OFF.

Pack Valves fail open when power is removed.

VENTILATING AIR CROSS CONNECTION

Both cabin and cockpit systems are cross connected so that one pack will ventilate both
areas.

A flow restricter on the cockpit lines limit cockpit flow to 33% of total flow available
from both ACU's.

MISTING OUT OF ACU EXHAUST DUCTS

Water from the water separator is directed over the ACU secondary cooler to increase
efficiency.

May cause a mist to exhaust from the louvered outlets on aft fuselage.

MANUAL TEMPERATURE CONTROL

Bypasses all auto control providing a direct line from rheostat to temp mixing valve.

If a pack starts putting out hot air on the ground or during climb or if there are intermit-
tent sounds like gravel being thrown through tubes or a whooshing sounds,.

The reason is probably a frozen water separator sock.

Turn OFF pack for 10 minutes to let sock defrost, then reinstate.

-or- increase heat setting.

Should not reoccur at altitude due to dry air.

Check functioning of anti-icing valve in pack.

If one pack goes to full hot or cold and cannot be manually controlled:

 Select affected pack OFF

Gulfstream IV Notes 2
Revision 2-98 Air Conditioning

 Use remaining pack to control cabin/cockpit temps

Full hot is The worst case situation.

Cabin Temperature Control

Recognized as a problem and being analyzed

(GAC Breakfast Minutes -- 07/16/91)

ASC 170 places air-conditioning temperature control on essential power so that can be
used on Standby Electrical Power System power (without mod, temp control goes to
full cold on Standby Electrical Power System only operations).

HIGH ALTITUDE OPERATIONS

“Cooling Turbine Hot” Message.

With Cowl and/or Wing Anti-Ice ON, 12th Stage Bleed opens.

400o+ bleed air is fed to packs.

Air is thinner allowing pack turbines to spin faster.

High RPM/high temp operations has led to turbine seizures.

All "COOL TURB HOT" annunciations have occurred between FL 270 and FL 420
(ACT Bypass open above FL 420 on current system).

ASC 198 has been created to open the ACT Bypass Shutoff Valve when either Cowl or
Wing Anti-Ice is ON, to slow down the turbine.

1167 & subs

Gulfstream IV Notes 1
Revision 2-98 Pressurization

12. PRESSURIZATION
OUTFLOW VALVE

Larger of two openings.

9.67 max differential.

Motor driven valve -- fails open.

Power sources: Auto mode -- Essential AC for power (AC motor)/Essential DC for
control
Manual mode -- Essential DC for power and control (DC motor)

SAFETY RELIEF VALVE

9.8 PSI max differential

Pneumatic only.

Provides: Cabin over-pressure protection.

Negative differential pressure protection.
Descent rate limiting (opens if the cabin descent rate exceeds 3000 FPM).

Cabin Pressure Oscillation

Cabin pressure oscillation can occur if the outflow valve and the safety valve are set
incorrectly.

It is possible for the high end tolerance of the automatic outflow valve to be set higher
than the low end tolerance of the safety valve.

The outflow valve maximum differential pressure range settings can be set between
9.41 and 9.67 PSI.

The safety valve maximum differential pressure range settings can be set between
9.55 and 9.8 PSI.

If the outflow valve maximum differential setting is set higher than the safety valve
maximum differential, the safety valve will be activated before the outflow valve
opens to maintain maximum differential and the result will be a rapid oscillation in
cabin pressure.
Gulfstream IV Notes 2
Revision 2-98 Pressurization

The fix for this problem is to readjust the maximum differential settings on the two
valves so that the safety valve value is higher than the outflow valve.

The temporary cockpit solution is to raise the cabin altitude to avoid reaching the safety
valve trigger differential.

AUTOMATIC PRESSURIZATION
Utilizes a pressure transucer.

Controlled by the Essential DC Bus.

Powered by the Essential AC Bus.

Requires input from DADC #1 or #2.

PRESSURIZATION CONTROL PANEL (PCP)

Powered by the Essential DC Bus.

Loss of Essential DC Power to the PCP

If Ess DC power is lost to the Pressurization Control Panel, control of the panel is lost.
Will be unable to switch from Flight mode to Ground mode for landing.

The Flight Tape may be adjusted to bring the cabin to the field elevation pressure.

Total Loss of Essential DC Power

If Ess DC Bus is lost totally, pressurization control is lost in automatic and manual
modes.

Automatic mode requires Ess DC power for control and Ess AC to actuate the
outflow valve.

Manual mode requires Ess DC power for control and actuation of the outflow
valve.

Removing Ess AC/DC power to the outflow valve will cause it to freeze in its
current position.

Pressurization control is lost and the cabin will climb (or descend) at the rate dictated by
the outflow valve position when it froze and the bleed air flow from the engines.
Gulfstream IV Notes 3
Revision 2-98 Pressurization

DISCRIMINATOR CIRCUIT

In Flight Mode: Cabin pressurization will go to the Flight Tape altitude setting unless the
Landing Tape is set higher than the flight tape. In this case the pressurization will always
go to the landing altitude.

In Landing Mode: Cabin pressurization will always go to the landing altitude set (if
possible).

ERRATIC PRESSURIZATION

If the pressurization is erratic in the Flight Mode, try using Landing Mode with the
landing elevation set to the cruise cabin altitude.

If the pressurization is erratic in the landing mode, try using the flight mode with the
cruise cabin altitude set to desired landing elevation.

PRESSURE CONTROLLER

In Landing Mode with weight ON wheels -- Outflow valve wide open.

In Flight Mode with weight ON wheels -- Outflow valve modulates to build 0.25 PSI
differential.

This pressure differential can make it difficult to open the emergency exits (plug
types) requiring about a 100 LB pull to overcome.

Open the main or baggage door first or go to landing mode to bleed off the pressure.

Note: If the Outflow Valve Position Indicator shows full closed in the flight mode on the
ground, a major fuselage leak is occurring (door cracked open, bad door seal(s).

Maximum Differential Pressure Versus Altitude

When at 36,000' and below -- max differential 8.55 PSI.

When at 36,000 to 43,000' -- differential increases between 8.55 and 9.45 PSI to maintain
a 6000' cabin.

At 43,000' plus -- differential stays at 9.45 and cabin rises to 6,500' max

EICAS Cabin Pressurization Warning occurs at 9,250'.

Gulfstream IV Notes 4
Revision 2-98 Pressurization

Masks deploy at 13,500' (place passenger oxygen to manual to avoid automatic system
shutting off oxygen when the cabin falls below 13,500' but is above 10,000').

RATE LIMITING

There are two types of rate limiting:  Pressurization Rate Limiting

 Depressurization Rate Limiting

The two forms of rate limiting are related in concept but different in execution.

PRESSURIZATION RATE LIMITING

In pressurization rate limiting the cabin pressure rate switch senses a cabin pressurization
(cabin descent) of 3000 FPM or greater. In this case, the Safety Valve is actuated to
prevent a cabin descent in excess of 3000 FPM up to the maximum differential pressure
allowed (safety relief pressure of 9.8 PSI).

DEPRESSURIZATION RATE LIMITING

This is a safeguard for the failure of the automatic pressurization system. If the outflow
valve opens fully due to a failure of the automatic pressurization control, the cabin
pressure rate switch will detect the rapid depressurization (cabin climb) of 3000 FPM
plus. It will disable the automatic pressurization system, close the outflow valve and
illuminate the manual control lights.

To regain automatic control of the system, the pilot must select manual and then reselect
auto. If the system again goes to depressurization rate limiting, the system must be
selected to the manual mode and controlled manually. All automatic pressurization
control is lost.

MANUAL PRESSURIZATION
Excludes the pressure transducer.

Powered by the Essential DC Bus only for control and power.

Does not require input from the DADC.

Failure of the DADC selected on the pressurization control panel will cause the system to
revert to manual operation.

Selection of the opposite DADC will allow return to automatic mode.

Gulfstream IV Notes 5
Revision 2-98 Pressurization

MANUAL MODE OPERATION

Best technique:

 Turn Autothrottle and Synch -- OFF

 Freeze one thrust lever. Leave at constant power setting of 900 PPH fuel flow.
 Turn other pack -- OFF
 Fly with other thrust lever
 Below 8000' select both bleed airs off and concentrate on the approach.

This technique provides a steady flow of air into cabin simplifying the difficult task of
modulating pressure manually.

Beep manual hold switch quickly Each beep about 200' FPM.

Wait 15 seconds for cabin rate of climb readout to indicate change.

MISCELLANEOUS
RAM SWITCH

Pushing the Ram Switch closes both bleed air shutoff valves.

With bleed air pressure at zero, ram air automatically enters the cabin through the normal
ducting.

This is controlled by a pressure check valve.

Closing both bleed air shutoff valves at their control switches does the same thing.

CABIN DEPRESSURIZATION IN FLIGHT

Most common causes of rapid depressurization:

In turbine A/C in general -- failed door seals.

In Gulfstream aircraft pressurization transducer problems.

Pressurization failures result in the outflow valve being driven full open.

There have been 2 cases of transducer failure and three cases of failed AC motors
in the GIV fleet (as of 3/97).
Gulfstream IV Notes 6
Revision 2-98 Pressurization

DOOR SEAL FAILURES

There have been numerous instances of Gulfstream aircraft depressurizing in flight due to
deflated Main and Baggage Door seals.

Ice from condensation in the 7th Stage Air is forming ice blocks and keeping the seals
from staying pressurized.

As the seals lose internal air pressure, the seals slowly deflate.

As the cabin air escapes past the deflating seal, the seal can be blown off its seat,
causing rapid depressurization.

With a deflated Main or Baggage Door Seal, cabin pressure can probably be
maintained with 35 PSI bleed manifold pressure.

A blown Main or Baggage Door Seal will result in rapid depressurization.

DOOR SEAL FIX -- ASC 364

Taps 12th Stage bleed air for Door Seal inflation.

Pressure increase from 16 PSI to 25 PSI.

PRESSURIZATION PROBLEMS DURING DESCENT

Check Valves are designed to maintain pressure in the door seals regardless of the bleed
air supply pressure.

If the check valves fail to hold pressure in the seals, the seals require 16 psi to keep doors
sealed.

The pneumatic system tries to maintain 18 psi minimum normally using 7th stage air.

In Autothrottle descents with Cowl and Wing Anti-Ice on, and a check valve failure, it is
possible that there will be insufficient pressurization to maintain cabin altitude, forcing
the outflow valve to rate limiting (occurs at 3000 FPM cabin climb rate).

If cabin climb rate exceeds 3000 FPM, the Depressurization Rate Limiting feature
causes the outflow valve to close if it is open.

Caused by limitation of Tay engines to provide sufficient bleed air at idle power with
anti-ice selected.
Gulfstream IV Notes 7
Revision 2-98 Pressurization

Can avoid by using vertical speed mode at lower rates or manual throttles with increased
drag.

CABIN PRESSURE STABILIZATION)

(ASC 313
Provides sufficient bleed air pressure during low power descents to maintain cabin
pressurization. 12th stage air is selected electrically when the power lever angle is
reduced below 62 degrees. This allows compensating 12th stage air before engine power
is reduced enough to cause a pressure sag. Bleed air pressure regulation is increased
from 18 to 30 PSI.

REMOTE AFT BAGGAGE DOOR SEAL

RELEASE
ASC 157 -- 1156 & subs

For effective smoke evacuation.

Allows the venting of cabin smoke out of the baggage door without a crewmember
going into the baggage compartment.

Note: If the handle cover cannot be reinstalled over the dump handle, the handle may
be in the dump position.

The same seal release can be accomplished by partially turning the baggage door
handle (if accessible).

Can maintain cabin pressurization with the baggage door cracked by putting on a
Cowl heat (additional 12th stage air pressure) or by going to max continuous power.

THREE-IN-ONE ALTIMETER

Direct reading, instant update -- good for manual control.

Reads altitude to 45,000'.

Standard digital cabin altimeter limited to 19,900' and updates only once per 15
seconds.

Contains:  Back up Altimeter

 Cabin Differential
 Rate of Climb

Is a very popular option, replaces pneumatic altimeter

Gulfstream IV Notes 8
Revision 2-98 Pressurization
Gulfstream IV Notes 1
Revision 2-98 Hydraulic Power Systems

13. HYDRAULIC POWER SYSTEMS

Two main systems:  Flight system

 Combined system

Each have own reservoirs.

Two backup systems:  Utility system (uses combined system reservoir)

 Auxiliary system (uses a sealed section of combined system
reservoir).

HYDRAULIC FLUIDS

Uses synthetic hydraulic oil type IV (purple Skydrol type).

Gear oleo struts use mineral based hydraulic fluid (red).

Do not mix red & purple.

Do not put red in hydraulic systems.

Do not put purple in gear struts.

May mix different brands of Type IV fluids.

A change in the hydraulic quantity indication after bleeding system pressure off indicates
air in reservoir -- needs bleeding.

COMBINED HYDRAULIC SYSTEM

Combined System quantity indication.

Level higher when gear down.

Level higher when reservoir warm

Goes down with cold soaking due to a high coefficient of thermal con-
traction/expansion.

In Case of Failure:

Immediately check the Combined System pressure to validate the warning.

If the pressure is low:

Gulfstream IV Notes 2
Revision 2-98 Hydraulic Power Systems

Check the Utility System pressure

If the pressure is low:

Disarm utility pump to avoid running dry.

If Utility System pressure is OK -- leave pump armed (on).

If flight hydraulic fluid overheats, the utility pump will automatically will
automatically shut down.

To avoid auto shutdown on approach, select the Utility Pump -- ON.

Will override auto shutdown.

If the Combined Hydraulic System is lost, and the Utility System is functional:

Lose:  Standby Electrical Power System standby generator (ABEX)

 Left reverser
 Flaps will be slower to operate.

COMBINED SYSTEM FLUID LOSS

If a Combined System fluid loss is experienced while flaps are moving, suspect a leak in
the flap hydraulics. Do not use the flaps further.

In this case:  Pull the Manual Flap Control CB to isolate the system
 Blow down the gear -- hydraulic fluid will be recovered in Combined
System reservoir.

With the flaps isolated, fluid recovered during gear blowdown should remain
available for other combined system components.

Check Auxiliary Pump operation when the checklist calls for lowering flaps to verify
that it is available for backup pedal brake pressure.

LOSS OF FLIGHT OR COMBINED HYDRAULIC SYSTEMS

Descend to FL 250 or below in case of loss of second system (unpowered flight controls
-- require FL 250 or below, 250 KTS or below and max bank of 20o.

UTILITY HYDRAULIC SYSTEM

Gulfstream IV Notes 3
Revision 2-98 Hydraulic Power Systems

GENERAL

Ten GPM flow.

The Utility Hydraulic System is powered by a hydraulic pump driven by a hydraulic

motor.

The hydraulic motor is powered by hydraulic fluid from the Flight Hydraulic System.

Utility System Control Valve. The valve that allows Flight Hydraulic System fluid to
power the Utility pump is powered closed and opens when power is removed from the
valve. (Fail-safe open.)

Utility System Off. When the Utility System is OFF (no flight hydraulic pressure to the
utility system pump) the valve is held shut by power from the Left Main DC bus.

Utility System Armed. When the Utility System is Armed (and not running), the
hydraulic valve is held shut by the Essential DC system.

Utility System Selected ON. When the Utility System is selected on, Flight System
hydraulic fluid is allowed to flow to the pump motor by removing all power to the valve
(relaxes open).

An ABEX-like noise coming from the rear equipment bay may be the utility pump.

A power failure to the shutoff valve would cause the system to turn ON.

If the Utility Pump is started due to a Combined Hydraulic System low pressure
transient (system falls below 800 PSI), turn OFF the Utility System Arm Switch then
return it to the ARM position.

POWER SOURCES

Arm switch -- Essential DC

On switch -- Left Main DC
Gulfstream IV Notes 4
Revision 2-98 Hydraulic Power Systems

AUXILIARY HYDRAULIC SYSTEM

The system pump is powered by a series wound DC motor.

Draws 66 amps DC from Battery Tie Bus.

When ON -- both Battery busses auto connected to Battery Tie Bus by the DC Power
Control Unit (PCU).

Battery switch lights will illuminate ON.

Auto ON -- the aux pump will latch ON if brakes are in use when ground spoilers are
stowed (due to pressure drop).

Will auto ON whenever combined pressure drops below 1500 PSI and toe brakes are
applied.

Can only handle one user at a time due to low capacity.

If flaps are selected up or down, the following are not available until the flaps stop:

 Toe brakes
 Main door closing

MAIN ENTRY DOOR RETRACTION

DOOR RETRACTION FAILURE

If the Main Entry Door fails to retract it may be a switch or an electrical problem. The
door retraction mechanism can be activated by a mechanical valve just aft of the door
near the Brake Control System (BCS) box.

1. Remove the access panel covering that area.

2. Turn the valve counter-clockwise.
3. Turn on the Auxiliary Pump.
4. When door has stopped, lock the door using the normal procedure.
5. Turn the Auxiliary Pump off.
6. Close the valve (clockwise turns).

Note: If the control valve is not returned to the closed position (fully clockwise), the
door, when unlocked, will fall partially open and then stop due to a hydraulic lock. If this
Gulfstream IV Notes 5
Revision 2-98 Hydraulic Power Systems

occurs, return the valve to the fully closed position and the door will continue to settle
open normally.

LOW HYDRAULIC PRESSURE INDICATIONS

On engine start-up, if hydraulic pressure is less than 3000 PSI and the pressure follows
thrust lever movement (RPM):

 Check that Flight Power Shutoff Valve is fully seated (stowed)

 If not, then pull handle fully out and re-stow.

Fluid is being returned to the reservoir before getting to the flight controls and causes
a pressure drop.

Slightly Raised Flight Power Shutoff Handle Causes Low Hydraulic Pressure

A GIV crew recently experienced low hydraulic pressures after engine start. With the right engine
running, flight pressure was 2,600 psi, utility was 2,600 psi. The crew advanced the power lever
and the flight went to 3,000 psi, the utility to 3,000 psi. Technicians bled the flight system
reservoir, but there was no change. They thought the cause could be an engine-driven pump or
pressure regulator. After about 1½ hours of troubleshooting, they discovered that the flight power
shutoff handle had been inadvertently raised about ¼ inch. The handle was closed, and the
hydraulic problem disappeared.

(GAC Breakfast Minutes – 05/13/97)

LOW COMBINED SYSTEM PRESSURE

Check for leaking Standby Electrical Power System shutoff valve.

Turn nosewheel steering switch OFF.

If pressure increases, this indicates an internal leak in the NWS actuator.

LOW FLIGHT HYDRAULIC SYSTEM PRESSURE

Check for Utility Shutoff Valve leakage (some utility pressure).

False Low Pressure Indication

There have been problems in reliability with the Flight Hydraulic low pressure switch. It
is possible that the switch has failed giving a false low pressure indication.

Check Flight Hydraulic quantity indication. If good –

Gulfstream IV Notes 6
Revision 2-98 Hydraulic Power Systems

Select the Utility Hydraulic pump ON.

If Utility Hydraulic pressure comes up, the Flight Hydraulic pressure is good.

Bad low pressure switch.

Actual Flight Hydraulic Pressure Failure

If the Flight Hydraulic system fails, turn off the Yaw Damper and Autopilot immediately.

The Yaw Damper or the Autopilot, if left engaged, will attempt to move the rudder to
maintain control. Power for this control comes throught Flight Hydraulic power only.

The autopilot controls the rudder through the yaw damper, turning it on
automatically.

Without Flight Hydraulic power, the rudder will not respond to Y/D or A/P commands.

The Y/D will assume a DADC #1 failure and switch to DADC #2. The rudder
will not respond to DADC #2 and the Y/D will kick it offline too. The SPZ-8X00
will now fail for lack of DADC input.

To regain the DADCs and the SPZ-8X00 system (EFIS/EICAS), both DADC C/Bs must
be pulled, the Y/D and A/P turned off, and then both DADC C/Bs reset.

The same DADC failures will occur on the ramp if the aircraft is sitting wing low with
engines off (no flight hydraulic pressure) and the yaw damper is selected on, for the same
reason.

HYDRAULIC QUANTITY INDICATIONS

For A/C SN's 1061-1158, EICAS may read lower than gauges on hydraulic panel due to resistors
placed in system before conversion to phase II.

Hydraulic panel gauges indicate correct quantities.

Resistors need to be removed

(GAC Breakfast Minutes -- 09/24/91)

In order to have a good hydraulic fluid indication, there must be at least 700 PSI on the
system.

GUST LOCK APPLICATION

Bleed hydraulic pressure from flight and combined systems before setting the gust lock.
Gulfstream IV Notes 7
Revision 2-98 Hydraulic Power Systems

Failure to do so can result in damage to the locking mechanism and possibly make
controls difficult to unlock.

If the Gust Lock is jammed by hydraulic pressure, it can be released by:

 Pulling flight power shut off handle Full up

 Unlock the gust lock
 Restow the flight power shut off handle.

BLEEDING FLIGHT & COMBINED SYSTEM PRESSURES

Bleed down with elevator only.

If ailerons are used, Flight Spoilers will be cycled up and down.

If the pressure bleeds to zero with boards up, they will remain up (they require
pressure to lower).

This does no damage but can be confusing to maintenance and next crew.
Gulfstream IV Notes 1
Revision 2-98 Landing Gear and Brakes

14. LANDING GEAR AND BRAKES

LANDING GEAR

GEAR DOORS

With combined or utility system pressure, gear doors close rapidly and forcefully.

GROUND SERVICE VALVE

Used to open/close doors on ground.

Note: If the ground service door is actuated with the gear pins out and the gear handle
up, gear will retract.

OVERWEIGHT LANDINGS

Max landing: 58,500 lbs MGLW based on 600 FPM touchdown.

Aircraft can land at 73,200 LB MGTOW with a descent rate of 360 FPM without
structural damage.

Retraction test and inspection is required after an overweight landing.

Two day inspection.

Can be eliminated if the aircraft has a G-Meter (standard on GIV SP's).

At maximum certified landing weight, up to 2.0 ‘G’ (2.3 ‘G’ SP) can be experienced
without requiring an inspection (with no abnormal side loads).

From max gross landing weight to maximum gross takeoff weight, the max g-force
declines linearly to 1.6 ‘G’ (1.7 ‘G’ SP).

See the AFM Supplemental Procedures Appendix C, "G-Monitor System" for

specific procedures/limitations.
Gulfstream IV Notes 2
Revision 2-98 Landing Gear and Brakes

LANDING G-METER -- ASC 118

Meter readout is in avionics bay with a feed to the TLM memory.

Records last 8 landings.

Records for 10 seconds after touchdown.

Only records "G's" when below 50' AGL.

$30,000 (1995). $28,000 (1998).

For overweight landings -- can reduce inspection requirements from two days to 5-6
hours.

The normal G-Meter reading is in the 1.3 to 1.6 ‘G’ range.

Maximum allowable landing ‘G’ is 2.0 ‘G’ for non SP/ASC 190 aircraft and 2.3 ‘G’
SP/ASC 190 aircraft.

Note: The use of auto ground spoilers increases g-force by about 0.3 g's. May want to
leave ground spoilers off until after touchdown in an overweight landing situation,
runway conditions permitting.

See the GAC/FSI Red Pilot Checklist, page E-128/129.

GEAR WARNING SYSTEM

GEAR WARNING SYSTEM TEST

Only works on ground -- can't be used to test the gear during suspected gear extension
failure.

Can be defeated (to confirm gear locked down):

 Pull both Rad Alt CB's

 Pull one thrust lever to idle

GEAR HANDLE LIGHT

Handle up/light out: Door closed indicator.

Handle down/light out: Gear locked indicator.

Gulfstream IV Notes 3
Revision 2-98 Landing Gear and Brakes

Emergency extension (gear locked down).

With handle up: 3 green and red handle (doors open).

With handle down 3 green and no red handle (gear locked).

GEAR HORN

With Landing Gear UP:

Auto-mutes above 1200' AGL with flaps 20 degrees or less.

Below 1200' AGL, with flaps 20 degrees or less, horn sounds with the power levers
pulled back below a 70 degree power lever angle.

Manually mutable.

Below 1200' AGL with flaps 22 degrees or greater, horn sounds with the power levers
pulled back below a 70 degree power lever angle.

Cannot be muted.

NOTE: A gear up landing is possible during a flaps 20o (or less) landing if gear horn is
manually muted -- no further warning is provided.

Auto-muting is disabled when one rad alt has failed.

Landing gear warning horn wired through radar altimeter logic.

This is a good test of the gear being down & locked if the gear indicating system has
failed.

Place gear down, select flaps below 22o.

No horn: gear down and locked.

No horn above 1200' AGL w/ flaps less than 22o.

Can mute horn on approach at any altitude if gear handle is down.

LANDING GEAR WARNING HORN MUTE BUTTON

Silence button on top sides of thrust lever handles.

Gulfstream IV Notes 4
Revision 2-98 Landing Gear and Brakes

Takeoff/Go-Around (TO/GA) button on lower sides of thrust levers -- don't confuse.

If the TO/GA button is accidentally pushed, autopilot disconnects, and Autothrottles

go to max climb power.

To disable Go-Around mode:  Push TO/GA button again

 Re-engage autopilot.

GEAR MALFUNCTION

LANDING GEAR FAILURE TO RETRACT

Can be caused by:  Main Gear pin(s) in place

 Door pin in place
 Closed gear uplock(s)
 Nitrogen in gear hydraulics

GEAR DOOR CONTROL VALVE PIN(S) LEFT IN -- ON GROUND

On ground after engine start, if door pins are discovered to have been left in gear after
engine start (combined or utility system pressurized):

Nose door -- can pull pin and stay clear of doors.

Main doors -- must shut down both engines and bleed Combined Hydraulic pressure
before pulling door pins, otherwise doors will slam shut rapidly.

Cannot pull pins and remain clear of doors.

GEAR DOOR CONTROL VALVE PIN(S) LEFT IN -- AIRBORNE

There are two types of gear door valves: the "-31" and the "-9".

With the pin left in the "-31" valve, the gear door will remain closed and the main gear
will partially retract and can be normally extended again.

With the pin left in the "-9" valve, the main gear will retract and the gear door will close,
but will not extend again.

A hydraulic lock will form in the door mechanism.

The gear may be blown down thru the doors.

Gulfstream IV Notes 5
Revision 2-98 Landing Gear and Brakes

MAIN GEAR UPLOCK CLOSED

After takeoff, landing gear was raised with one Main gear uplock closed.

Cockpit indications: Light in handle cycled on and off and gear door was heard to cycle open and
closed with gear handle light.

Affected gear could not be locked up.

GAC said that uplock could be bumped during maintenance or cleaning and appear to be open
on preflight only to snap closed during taxi vibration
(GAC Breakfast Minutes -- 04/09/91)

How To Open A Closed Uplock:

 Ensure that control valves are pinned

 Open ground service valve until aux pump goes to high pitch (unloads)
All uplocks will be open

NITROGEN IN GEAR SYSTEM

If nitrogen from the blow down bottle gets into the gear hydraulics, a failure to retract can
occur.

 Check Emergency Gear "T" Handle full down

 Pull Dump Valve "D" ring up
 Reset "D" Ring after 10 seconds
 Landing Gear Handle - RAISE

PARTIAL GEAR EXTENSION

Gulfstream recommends that if, after all attempts to lower three landing gear fail:

Only two gear will lock down, land on the two.

If one Main gear does not fully extend, land with full flaps.

The flap on the failed side will hold the wing tip off the runway providing a
shorter drag moment arm and a less costly repair.

Turn ground spoilers OFF -- maintain lift on wing.

(Russ Whitney -- FSI-SAV sim instructor)

Gulfstream IV Notes 6
Revision 2-98 Landing Gear and Brakes

If only one gear will lock down, try to retract it and land gear up.

DISCONNECTED LANDING GEAR DOWN-AND-LOCKED SWITCH

Recently two GIV operators have reported a similar incident which occurred during the approach
to landing phase of the flight. When the landing gear handle was selected to the gear down
position, not all of the down-and-locked “green light” indicators showed the selected gear
configuration.

In both cases, the alternate Airplane Flight Manual (AFM) procedures were followed to ensure
landing gear extension, and uneventful landings were made. A disconnected down-and-locked
switch was found to be the cause of each problem.

One might think that reconnecting the switch would return normal operation. However, the system
does not work that way. Whether you are in your hangar, in a service center, on the road, or
anywhere, the airplane has to be jacked and leveled, a hydraulic power source attained, and the
landing gear control sequence operated not once, but many times. Maintenance personnel call
this procedure “swinging the gear.” When this is complied with, you can release the aircraft to a
“return to service” status. The procedure takes a minimum of four to five hours.

When you preflight an aircraft, the three “down-and-locked” switches are items you can put your
hand on and feel, as well as check visually. You can ask yourself, “Is it secure?”, “Can I see the
lock tangs of the plug visible through the inspection ports of the mating plug?” Alleviate doubt by
knowing that the three connecting plugs are secure.

Note: At the beginning of the Q & A session, one GIV operator commented on the landing gear
down-and-locked indication. They had an intermittent problem on the left main gear. They could
re-seat the “warning lights dim and test box” (29 box) and the light would come back on. It turned
out that channel 235 of the box was malfunctioning.
(GAC Breakfast Minutes – 7/28/98)

EMERGENCY GEAR EXTENSION

Max Gear Emergency extension speed 175 KT.

Max operating speed (once gear is down) is 250 KT (AFM 3-18 15 Jan 91)
Gear doors remain open but no door open speed limit.

Emergency gear extension normally takes 6-9 seconds.

Gear handle must be down to have:

 Nosewheel Steering (will not get a failed message if handle left up but steering
will be inoperative)
 Normal down & locked indication -- handle light will go out if 3 gear down and
locked and handle down.
Gulfstream IV Notes 7
Revision 2-98 Landing Gear and Brakes

After blowing down gear, maintenance must swing the gear on jacks many times to get
nitrogen out of hydraulic system.

Failure to do so can lead to a sequencing problem later.

EMERGENCY EXTENSION WITH GEAR ALREADY DOWN

Gear blowdown may be performed with gear already down as a backup technique if gear
downlock integrity suspected.

Will cause no damage.

If Landing Gear are not fully down and locked after an emergency extension with a
Combined Hydraulic System failure, no further systems action is possible.

 May attempt yawing a main gear into the locked position (has been done).
 Pulling "G's" may lock the nose gear down.

GEAR DOWN FERRY

Ferry permit required.

Pin gear down (remove flags).

Leave doors open (closing only possible with gear reset).

Plan below 20,000'/250 KTS.

Fuel planning:

Take normal consumption/range numbers for speed and altitude used.

Double that consumption figure.

Slowing down 10-20 KTS will greatly improve consumption.

If possible, use sound suppressing head sets -- wind noises are high.

LANDING GEAR RETRACTION PROBLEMS

During 1997, several GIVs had landing gear retraction failures. Scenario: During departure, when
the crew selects the gear handle up, the nose gear remains extended and the main gear will be
somewhere between extended to fully retracted. The crew cycles the gear a couple of times with
Gulfstream IV Notes 8
Revision 2-98 Landing Gear and Brakes

no change, then uses the emergency extension system to successfully blow down the gear. The
crew lands the aircraft safely. We have noted signs of residual hydraulic fluid on the side of the
aircraft after the incident.

Gulfstream identified a full-time team (12/97) to work this issue. This cross-functional team
includes Engineering, Tech Ops, Purchasing, Quality, and other areas. We are dedicated to
resolving this issue.

The team released Maintenance and Operations Letter TO-MOL-97-0020, dated 12/17/97, to give
an update of what is happening and some things to be aware of.

Two landing gear related Customer Bulletins were released. CB 84, dated 6/27/97, addresses
the emergency T-handle rigging and safetying. CB 89, dated 12/23/97, addresses the landing
gear dump valve “D” ring rigging.

Landing Gear Team Actions/Findings

The team gathered and reviewed data from all sources concerning the individual gear retraction
events. We also put together a questionnaire and sent it to the operators to pull in all the
information we could. The information was compiled into a database to look for common points,
and possible and probable causes of the retraction difficulties. The probable cause seems to be
that the landing gear system actuator shuttle valves (total of nine) are bypassing, causing the
dump valves to trip.

Just before the holidays, we instrumented a production GIV aircraft for hydraulic system
pressures and flows to see if we could duplicate the occurrence. We tested the aircraft in the
normal configuration with everything working fine. Then we used a test instrumentation shuttle
that would bypass. We were able to duplicate what we were seeing in the field and confirmed that
a bypassing shuttle will cause the retraction problem.

We have done a detailed review of landing gear components from the field incidents and off-the-
shelf. We looked at detail drawings for changes that may have affected operation, tolerance
stackups, etc. We found there was a shuttle valve manufacturer change; there were minor
changes made to two of the nine shuttle valves on the aircraft. We ran the components through
an acceptance test procedure (ATP) and also did some testing outside the normal range to see if
we could duplicate what was being seen. From that testing, we were able to see some of the
shuttle valves hanging up and bypassing. We were also able to see some internal flow problems
with the dump valves.

We are working with the suppliers on these two items. Some of the data taken from the
production aircraft testing has been given to the supplier to try to set up shuttle valve testing to
see if we can duplicate the offset and bypass conditions. We have not heard back from the
supplier.

Similar testing is being done with the dump valves. We saw some discrepancies with the internal
interflow. We are working with the supplier to ensure that the ATP catches this.

The team is working on a long-term solution. We are focusing on the shuttle design to see if we
need another manufacturer or a design change. We have tried to obtain another source of shuttle
valves in case there is a manufacturing flaw. We will keep you posted through MOLs or Breakfast
Minutes updates.

Current Recommendations for GIV Operators

Tim closed with recommendations for you, the operator, to avoid gear retraction difficulties. This
is based on common points from last year’s gear retraction events.
Gulfstream IV Notes 9
Revision 2-98 Landing Gear and Brakes

 During preflight, check for signs of hydraulic fluid venting from the emergency release vent
(just aft of the nose landing gear doors on the right-hand fuselage). If you find fluid, call Technical
Operations at 912-965-3241 for assistance.

 Listen for any abnormal sounds during startup and taxi. Crews report hearing thumps and
thuds similar to the nose wheel steering being turned off and on, and the sound of bypassing
fluid. If your crew hears these sounds, we recommend that they check the emergency release
vent before takeoff.

 Comply with CB 84 and CB 89 as soon as you can.

Note: We have seen a CB 89 dimension callout discrepancy for each dump valve button
(Step II.F). The range should be 0.240-0.260 inch. An amendment is forthcoming.

 Follow Flight Manual emergency extension procedures to the letter. This ensures that the
gear can be blown down.

 Crews should pull up the Engine Instrument -- Crew Advisory System (EICAS) hydraulic page
during startup and taxi out. This will allow monitoring of the hydraulic quantity to see if fluid is
being ported overboard, in case no bypassing fluid sounds, etc. were heard.

As our investigation continues, we will keep you posted of further developments.

(GAC Breakfast Minutes – (01/06/98 )

RESOLUTION FOR LANDING GEAR RETRACTION PROBLEMS

Dave updated the Customer Breakfast audience on developments since Tim Farley’s
presentation on “Landing Gear Team Investigation Resolving Retraction Issue.” (Ref. Jan. 6,
1998 issue of Breakfast Minutes.)

Gulfstream has had a multi-discipline team, with members from various areas of the company,
working on the issue of landing gear retraction on the GIV. The following scenario typifies the
problem. With the gear handle up, the gear fails to fully retract. Subsequently, the GIV operator
will put the gear handle down and fail to get three “down and locked” indications. The gear does
not go all the way down. The use of the emergency blowdown system is then required to get all
three gears down and locked. In most cases, operators report seeing expelled hydraulic fluid from
the overboard vent, and in some instances, the pilots hear a high-pressure hissing noise,
indicating the bypassing of fluid.

The multi-discipline team is nearing completion of their work. General findings indicate the
primary cause of the problem is Foreign Object Debris (FOD) in the landing gear system. The
FOD caused one of the nine landing gear hydraulic shuttles within the system to bypass.
Bypassing of fluid causes an out-of-sequence activation of one of the three dump valves. Fluid
goes into the vent line and then, if pressure builds up, it will trip one of the dump valves.

We have verified in several cases FOD damage to the valve poppet face. The poppet face is
made of what we call Nylotron™. It is kind of like a hard Teflon™. FOD has caused imprints in the
poppet face, as witnessed by us. We have also found small particles still embedded in the face.
We have also seen damage and a little bit of dangling threads on some of these valves.

From experience working these events, we know that the sidebrace shuttle valves appear to be
more prone to this occurrence. In consideration of this, Gulfstream is launching a series of
corrective actions. We want to purge FOD from all GIV aircraft that have encountered landing
Gulfstream IV Notes 10
Revision 2-98 Landing Gear and Brakes

gear system problems (i.e., aircraft that had a problem where the gear did not come up or did not
go all the way down, or airplanes that tend to be chronic leakers).

We will be contacting operators of affected aircraft, over the next few weeks, to undergo
corrective procedure here at Gulfstream. We have already remedied this problem in two GIVs.
The corrective procedure entails flushing the lines and replacing shuttle valves with what we call
“FOD-free valves.” These valves simply have had an extra degree of inspection by Gulfstream
personnel (as opposed to relying solely on the supplier).

We have an inventory of FOD-free valves on-hand and, to be prudent, would like to replace the
suspect valves. As we go through the de-FOD process on these airplanes, we are going to look
at the fluid and capture any particles that might be located in the fluid. Findings from de-FODing
of these airplanes will help determine if any other airplanes might benefit from the same
procedures.

In addition, FOD-free sidebrace shuttle valves will be sent to replace any 1159SCH223-5 valves;
valves will be sent to all operators of GIVs 1201 and subsequent aircraft. This involves only the
sidebrace valves, which are fairly easy to replace. The events that have occurred have been
primarily in the later GIVs, but we feel it is advisable to replace these valves in earlier aircraft as
well.

A redesign of the shuttle valve is underway and is expected to be available for production and
retrofit by May 1998. Gulfstream will redouble our efforts, both in production and with our
suppliers, to make sure that we receive, inspect, and then install, FOD-free valves on your
aircraft. A GIV Maintenance and Operations Letter (MOL) addressing this effort is being issued
soon.
(GAC Breakfast Minutes – 03/03/98)

NOSEWHEEL STEERING
Good on some GIV's and bad on others.
A maximum of 82 degrees of nosewheel steering is available.

78 degrees through the tiller wheel and 7 degrees through the rudder pedals.

Both tiller wheel and rudder pedal deflection are required to achieve the full 82
degrees of nosewheel rotation.

Nosewheel steering is powered through the Combined or Utility Hydraulic Systems.

If powered by the Utility System, the gear handle must be in the down position in order
for the Utility System to power the steering.

Aircraft with all steering mod's incorporated seem to be OK.

To work:  Must have nosewheel down & locked

 Landing gear selector down (safety interlock)
 Weight on nosewheel
Gulfstream IV Notes 11
Revision 2-98 Landing Gear and Brakes

Weight on nosewheel starts a one second timer to phase in rudder pedal commanded turn.

Prevents rapid turns on crosswind touchdowns as nosewheel steering becomes

effective with large crosswind rudder applications.

GAC recommends nosewheel steering be turned OFF at shutdown.

ASC 302 -- Rudder Pedal Steering Switch

Allows rudder pedal steering to be turned off. The switch is housed in its own control
panel which is located just aft of the tiller wheel. There is a small blue indicator light
located near the tiller wheel showing that rudder pedal steering has been disconnected.

Rudder pedal steering should be selected ON for crosswind takeoff.

NOSEWHEEL STEERING LOSS

During Braking: There have been cases of temporarily losing N/W steering during
braking on roll-out.

Due to low Tay idle -- not sufficient excess volume to handle all combined system
users.

If occurs: increase left power lever to increase hydraulic flow.

THE EFFECT OF COMBINED AND UTILITY HYDRAULIC SYSTEM LOSS:

There will be no nosewheel steering.

There will be no nosewheel steering failure indication.

Will receive indication only for electrical fault/failure in steer by wire.

NOSE WHEEL STEERING CAN HAVE DELAYED FAILURE INDICATION

Earlier this year, a GIV crew experienced a nose wheel steering problem at touchdown, and the
aircraft yawed left about 10°. The system detected the fault and shut itself down, turning the
steering into the caster mode and indicating a nose steering failure on EICAS. The crew
controlled and steered the aircraft with differential braking and completed rollout without further
incident.

The steering problem was traced to hydraulic contamination of the hydraulic-mechanical servo
valve. This caused it to port fluid, even though there was no steering input. The system detected
this and shut down after the nose nutcracker was made. At the customer’s request, we are
evaluating an in-line filter on his aircraft to prevent this from happening again. Gulfstream
engineering reviewed the GIV steering system Failure Modes and Effect Analysis (FMEA) data.
Gulfstream IV Notes 12
Revision 2-98 Landing Gear and Brakes

We found this occurrence was covered in the FMEA data during the certification process. We
also reviewed reliability data, which showed we have not seen a large frequency of this event.

We want GIV crews to be aware that there is a potential for the nose steering to indicate it is off
only after the nose wheel has touched down.
(GAC Breakfast Minutes – 10/28/97)

TOWING

Do not put tow bar on nose gear with scissors attached.

Can do extensive damage to the gear if towed ($50,000).

NOSEWHEEL STEERING PROBLEMS

Numerous problems have been reported.

 Inoperative steering
 Locked in hard turn
 Intermittent sluggish steering
 Steering fail messages

TROUBLESHOOTING:

1. Verify modification status (ASCs & CB's).

2. Verify problem by maintenance manual checks, wiring diagrams and component

adjustments.

3. Eliminate aircraft wiring discrepancies.

4. Do not swap components except as last resort (two operators burned out ECU's by
swapping components with faulty wiring).

If none of the above solves problem, ASC 260 updates entire steering system
(GAC Breakfast Minutes -- 02/08/94)

NUTCRACKER SYSTEM
Nutcracker System (Weight ON Wheels -- WOW).

One switch on each main gear and one on nose gear.

MAIN GEAR NUTCRACKER SYSTEM

Gulfstream IV Notes 13
Revision 2-98 Landing Gear and Brakes

Switches open when airborne (power to Nutcracker System removed).

O O O
L R
Nutcracker Nutcracker Nutcracker

Pulling the Nutcracker CB (CPO) (center of three CB's) removes power and forces
system to airborne mode.

L & R Nutcracker CB's control power to the Flight Idle (Dual Datum) power system
(67% HP airborne w/ flaps > 22o, 47% HP on ground).

Pulling either breaker will send the same side engine to the flight idle mode
regardless of WOW/flap status.

Either of Main gear switches to airborne mode (open) send system to airborne mode.

Both switches must be on ground (closed) for system to be in ground mode.

LANDING WITH THE NUTCRACKER SYSTEM IN THE AIRBORNE MODE

The following items will function on landing after wheel spin-up with one or both of the
nutcracker switches in the airborne position (switches open):

 Ground Spoilers
 Brake Anti-skid
 No Ground Spoiler light (If either Nutcracker Switch is airborne)
 Aux Pump arming circuit

Ground Spoilers will deploy on wheel spin-up to 65 KTS and will stow at below 25
KTS accompanied by the "NO GND SPOILERS" light on the glareshield.

Might expect disruption to the brakes and steering during the auto-retraction.

Anti-Skid

Both Nutcrackers in Airborne Mode: Will come on with wheel spin up above 40
KTS until wheels slow down to 15 KTS then there will be no brakes until anti-skid
switch turned OFF.

One Nutcracker in the Ground Mode: Will revert to manual brakes on

deceleration below 15 KTS.

Thrust Reversers will deploy for A/C with ASC 166 on wheel spin up to 65 KTS.
Gulfstream IV Notes 14
Revision 2-98 Landing Gear and Brakes

Expect to see a red CAS message "L-R REV UNLOCK" since the system thinks it is
airborne.

Flight Idle System engines will drop to ground idle (47% HP) upon wheel spin up to 65
KT and increase to 67% HP RPM at 25 KT (only on the side with the nutcracker in the
airborne mode).

Indications of Landing in the Airborne Mode

On pre-ASC 166 aircraft the lighting of the green "REV ARM" Lights on touchdown
indicates that the nutcracker system is in the Ground Mode.

No green :"REV ARM" lights and (and no thrust reverser deployment) on touchdown
means the nutcracker is still airborne.

On post ASC 166 aircraft, the "REV ARM" lights will come on with a wheel spin-up of
65 KTS on one wheel of each strut even if nutcracker remains airborne.

This will be followed by the appearance of the red "L-R REV UNLOCK" EICAS
message This should be taken as an indication that the nutcracker system is in the
airborne mode and that brakes will fail below 15 KTAS unless anti-skid is turned OFF
approaching 15 KTAS.

Summary Note:

"L-R REV UNLOCK" and "NO GND SPOILERS"

With the Nutcracker System in the airborne mode (either or both N/C switches airborne)
on landing, expect to see the above annunciations, anti-skid to become effective with
wheels spin up above 40 KTS, ground spoilers and thrust reversers (on ASC 166 aircraft)
to deploy at 65 KTS spin-up, engines to drop from 67% to 47% HP RPM.

At 25 KT ground speed, thrust reversers and ground spoilers will stow, temporarily
disrupting brakes and nose wheel steering while both engines will spool up to 67% HP
RPM followed by Anti-skid failure (total brake failure if both N/C switches airborne) at
15 KT ground speed (until A/S switch selected off).

NUTCRACKER SYSTEM IN GROUND MODE WHILE AIRBORNE

Normally if one switch is stuck in the ground mode while airborne, the system will be in
the airborne mode and all systems normally available airborne will be available.

On the ground, both switches will be in ground mode and the system will be in ground
mode.
Gulfstream IV Notes 15
Revision 2-98 Landing Gear and Brakes

If one switch is damaged in the open position (air mode), all systems will be normal
airborne.

On landing, system will remain in the air mode.

Systems available on the ground:

 Anti-Skid (wheel spin up)

 Aux Pump arm (toe brake back up pressure)
 T/R's if wheel spin up ASC installed

Problem: System stuck in ground mode after takeoff

Can occur after slush operations (both Main gear switches frozen).

Symptoms:  Gear will not retract (blocked by solenoid)

 Pressurization differential remains at 0.25 PSI.

Possible Results:  Ground spoilers will deploy if armed and power levers retarded
 T/R's will deploy if selected.

Action:  Check nutcracker test switch -- two green indicate air mode.

If ground mode:  Hold the Nutcracker Test Switch depressed (puts A/C in the
airborne mode).
 Flight Spoilers -- DISARM
 Raise gear with Solenoid Override (if necessary)
 Pull center Nutcracker CB (CPO).

Procedure in FSI checklist.

Note: If frozen nutcracker switches are suspected.

 Try using Wing A/I to thaw the switches

 Reset center Nutcracker CB
 Do Nutcracker Test. If satisfactory, problem solved.

NUTCRACKER TEST SWITCH

In flight, two green lights will indicate that both switches are in the air mode.

One light out (bulb test good) indicates that:

 One system is in ground mode.

Gulfstream IV Notes 16
Revision 2-98 Landing Gear and Brakes

-or-
 One squat switch may be damaged (system will think that it is on the ground).

NUTCRACKER CORROSION PROBLEMS

Older GIV's may develop corrosion in the wire bundle junction in the center of the main
wheel wells.

NOSEWHEEL NUTCRACKER

Does not tie into the main gear nutcracker system.

Does not test with the nutcracker test switch.

Controls:  T/O Configuration Warning

 Nosewheel Steering

If nose wheel WOW remains in ground mode, nosewheel remains steerable in wheel well
with jam potential.

If this occurs:  Turn N/W steering - OFF

 Raise gear

Leave N/W steering OFF until after gear is lowered for landing.

GIV - ASC 135 AMENDMENT TO ELIMINATE UNNECESSARY

NUTCRACKER CIRCUIT

After extensively troubleshooting an engine start circuit breaker that popped during a normal
engine start, technicians found the problem was caused by a combination of ASC 135 circuitry
(ECS Pack Sequencing During Engine Start) and a set of circumstances that could easily happen
to anyone.

The aircraft was lightly fueled, allowing the nose strut to extend more than normal, and the nose
nutcracker switch had been adjusted to the higher end. Combining these two factors put the nose
nutcracker in the air mode, allowing a direct path to ground through nose wheel nutcracker relay
No. 1 (325K10), whenever Engine Start or Crank was selected.

An engineering study found this particular nutcracker circuit is unnecessary and can be
eliminated. An ASC amendment will be released to remove this circuit.
(GAC Breakfast Minutes – 07/15/97)
Gulfstream IV Notes 17
Revision 2-98 Landing Gear and Brakes

BRAKE SYSTEM
GOODYEAR BRAKE BY WIRE SYSTEM
Standard baseline GIV brake system

System overview:

Brake pedals electrically signal brake electronic control unit (brake ECU) which pro-
vides the brake logic to the Hydraulic Brake Control Module (HBM) which modu-
lates fluid pressure to carbon disk brakes. The brakes may be applied by both pilots
simultaneously. The side applying the most pressure will control the brakes.

CAS Hydraulic System page brake pedal pressure indications comes from inboard brakes
(brakes 2 & 3) only.

Pressure may be more or less to outside brakes.

BRAKE MESSAGES

“BRAKE MAINTENANCE REQUIRED” blue light.

Wheel speed sensors do not agree.

Light does not latch on.

Will extinguish when wheel rotation stops (no speed disagreement) even though
problem still remains.

Expect “BRAKE MAINTENANCE” light to extinguish:

 On takeoff
 On parking

ANTI-SKID

Pressure is modulated to keep wheel pair on the verge of a skid.

The wheels are paired (two left together and two right together).

If one of the paired wheels spins 30% slower than the other, brake pressure is
removed from that pair until speeds are within 30%.

One flat or missing wheel in pair will disable both paired wheels with anti-skid ON.
Gulfstream IV Notes 18
Revision 2-98 Landing Gear and Brakes

Anti-skid is optimized for maximum braking.

If going into a contaminated runway, use maximum braking.

Brake pressure will be available with wheel spin up to 40 KT wheel spin-up or

weight on wheels.

ANTI-SKID FAILURE CONSIDERATIONS

Bang-Bang Breaking -- with anti-skid ON, will revert to bang-bang braking.

Turn OFF by 100 KTS to avoid rough, jerky braking.

Wheel Snubbing on Retraction -- provided by the anti-skid system.

Failure of the anti-skid system on takeoff disables auto wheel snubbing.

Use the following procedure:

 A/S -- OFF
 Brakes -- APPLY
 Gear -- RETRACT

Partial Brake Failure: In the case of a tire or wheel failure, one wheel's speed will fail
to match other within 30% possibly causing a permanent loss of brake pressure to that
wheel pair.

 Turning Anti-skid OFF will return brake pressure.

 Pulling BCS #1 & #2 CB's will revert system to bang-bang braking and preserve
some anti-skid protection.

Note: during an Anti-skid OFF landing, apply toe brakes to maintain 500 PSI on
hydraulic system or brake page of EICAS.

This will give a nice deceleration without wheel lock-up.

Brake Fires -- Four known brake fires on GIV's (as of 10/93).

1 minor, 3 major -- all occurred with parking brake set.

Temperature peaks in 10-15 minutes after landing/abort

Gulfstream IV Notes 19
Revision 2-98 Landing Gear and Brakes

BRAKE CONTROL SYSTEM (BCS)

Two channels.

Default system -- Channel 1.

Powered by Essential DC Bus or #1 e-batt.

Auto changeover to Channel 2 on malfunction.

Powered by Essential DC Bus only.

Normal brake control power source -- Essential DC Bus.

BCS #1 failure will result in blue "BRAKE MAINTENANCE FAIL" EICAS message.

BCS #2 will be in use.

If BCS #2 fails or if BCS #2 MALF MESSAGE CB pops -- all four messages display
despite good brakes and anti-skid.

If happens, check brake pressure.

No way to confirm anti-skid, though should not be affected.

To Check Pedal Brake Pressure in Flight (Brake Confidence Check):

 Press Brake Nutcracker Override -- hold for 10 seconds

Simulates weight on wheels for brakes only
 Depress pedal brakes individually and look for pressure indication on same side
Ensure no cross braking.

Alternate Technique

 Anti-skid switch -- OFF

 Depress pedal brakes

Besides checking braking capability, the confidence check allows warm fluid into brakes
for smoother initial braking.

Note: parking brake pressure cannot be displayed in baseline GIV on ground or airborne.

To Reset Brake Messages on the Ground:

Stop and set parking brake before pulling BCS #1 & #2.

Will force system to bang-bang braking.

Gulfstream IV Notes 20
Revision 2-98 Landing Gear and Brakes

GAC Brake Expert: Greg Hammerstein/Flight Test.

Need functional e-batt #1 to have backup power to the Brake Control System (BCS #1) for brake
by wire.

If the e-batt #1 is physically removed from the rack, then BCS #1 is un-powered.

Bang-bang braking will result.

One student in class reported getting smoother braking on landing by using Wing A/I on descent
to warm up wheel well area and brakes.

Gulfstream reports that Wing A/I is not effective on GIV brakes though may be of some help
for II's & III's
(GAC Breakfast Minutes -- 01/25/94)

FROZEN BRAKES

Three instances reported of GIV brakes freezing during winter of '94.

Two on ramp and one on landing.

All three were Dunlop carbon brakes.

All brake systems are vulnerable to freezing.

First reported frozen brakes since one GIV incidence in 1991.

To Avoid Freezing

Ground operations:

 Avoid puddles and slush

 Chock wheels and release brakes
 Visually check brakes, wheels and wells for snow, slush, or ice
 Set brakes just prior to engine start and release brakes as soon as chocked
 Taxi as soon as possible after engine start
 Use brakes during taxi to build up heat to dissipate any moisture (100o or higher w/ brake
monitor)
 When stopped, perform several brake applications of 3000 PSI to exercise brake stacks
and discourage ice buildup
 Avoid temptation to set parking brake for any length of time
 Hangar A/C ASAP after taxi in.

After takeoff:

 Delay gear retraction if practical (recommended to wait for wheel spindown)

 If possible, cycle gear once or twice
 Briefing passengers is recommended

In Flight:
Gulfstream IV Notes 21
Revision 2-98 Landing Gear and Brakes

With ASC 381 (Changes the plumbing of the wing anti-ice bleed exhaust duct to increase
warming air flow to the wheel well area for brake warming.) wing anti-ice may be used to warm
the brakes while in the wheel wells.

Approach:

 Lower gear early (will warm up to total air temp in 3-5 minutes)
 Perform several 3000 PSI brake applications airborne.

To apply brake pressure on brake-by-wire: turn OFF Anti-skid or use Brake Nutcracker Override
Switch to accomplish (A/S-- ON afterwards).

With Hydro-mechanical Analog Brakes (HMAB) turn OFF A/S to accomplish (A/S -- ON again
afterwards).

HMAB systems have no Brake Nutcracker Override Switch.

Landing:

 Perform firm touchdown to break ice bond (pre-brief passengers)

 Use firm braking techniques, if possible, following Thrust Reverser deployment.

All of the above on frozen brakes taken from John O'Meara, GAC Flight Operations
(GAC Breakfast Minutes -- 01/25/94)

THAWING FROZEN BRAKES -- GROUND PROCEDURES

Use of warm air most effective.

Avoid using deicing fluid.

Water in 50-50 mixture will actually contribute to brake freezing.

100% deicer will make brakes slick

BRAKE FAILURE ON LANDING:

With the combined and utility hydraulic systems failed, flaps will be powered at a
very slow rate by the auxiliary hydraulic system.

The same aux system must power the pedal brakes -- but the flaps have priority for
pressure.

If flaps are selected late on final, they may still be moving during touchdown,
starving brake pressure.

To avoid -- start flaps down early.

Gulfstream IV Notes 22
Revision 2-98 Landing Gear and Brakes

To get brakes back -- select emergency flap switch: ON (freezes flaps until manual
flap control moved).

SINGLE ENGINE TAXI

During single engine taxi, it is best to taxi on the left engine to maintain combined
hydraulic system pressure to the brakes.

During a quick passenger drop, with a single engine taxi on the right engine, don't disarm
the utility or Auxiliary hydraulic systems.

The utility system provides primary toe brake pressure.

Expect to hear the utility pump.

The aux system provides backup toe brake pressure.

Don't disarm E-Batts (backup electrical power to the Brake ECU).

CARBON BRAKE GRABBING

One of causes is carbon dust accumulation.

ABS (brake manufacturer) has issued a service bulletin "Gulfstream IV-32-3" covering cleaning
and restacking of disks
(GAC Breakfast Minutes -- 09/24/91)

BRAKE SOFTWARE UPDATE

Latest brake ECU software out is "-3" (as of 10/93).

Not everyone has updated to "-3" (10/93).

Latest hydraulic brake module out is "-4" or "-5".

Everyone has (10/93).

If you have both mods, don't need to conduct brake confidence checks.

The Confidence check still an effective way to warm up brake hydraulics.

PARKING BRAKE
Gulfstream IV Notes 23
Revision 2-98 Landing Gear and Brakes

Parking brake meters fluid during first 1/2 to 1" of travel.

Then allows full system pressure to brakes.

There is no indication of parking brake pressure on hydraulic page.

PARKING BRAKE CHECK VALVE AND SEALS

Parking brake has check valve and seals to prevent brake pressure bleed down if
accumulator bleeds down.

This is only on GIV's and G-III's with metered parking brake.

Do not bleed down brake accumulator pressure at the nosewheel well dump valve if
the parking brake is set, can ruin seals at check valve.

Blown seals will not affect parking brake effectiveness as long as accumulator is
pressurized.

DUNLOP BRAKE-BY-WIRE SYSTEM

Available to GIV operators through ASC 190.

Well regarded by operators using the system.

DUNLOP HYDRO-MECHANICAL ANALOG BRAKE (HMAB) SYSTEM

Provided on GIV SP's SN 1214 & subs.

Comparable to G-II brakes.

Mechanically joined from pilots pedals to hydraulic valves (metal rods through firewall.

Brake Pressure Indications on the Hydraulics Systems page of the CAS are provided by
brakes 1 & 3.

Anti-Skid -- an Anti-skid speed sensor module mounted on each wheel.

Wheels are now paired with opposite side wheels (i.e.; wheels 1 & 4/wheels 2 &3).

If one of the opposite paired wheels slows by more than 30% of the other, pressure is
released to that individual wheel until it matches the other paired wheel.
Gulfstream IV Notes 24
Revision 2-98 Landing Gear and Brakes

Will release a single wheel of a pair if it starts to skid.

Allows better Anti-skid sensing and reduces chance of Anti-skid failure on one side
with a blown tire.

Advantage to this system: If one wheel is lost, braking is only reduced by 25%.

Disadvantage: With 4 valves (compared to 2 in Brake-By-Wire System), this system is

heavier.

Anti-skid -- OFF -- pressure over 300 PSI will blow tires

ASC 307 retrofits Dunlop wheels/brakes/tires to baseline GIV's.

Can tell if aircraft has HMAB system -- no Brake Nutcracker Override Switch.

Provides Parking Brake pressure indication

When Landing With Parking Brake Only, don't exceed 300 PSI braking to avoid
skidding.

Auxiliary Hydraulic Pressure Switch Can Fail, Creating Indication Anomalies

Aircraft with the Hydro-Mechanical Analog Brake (HMAB) system¾GIV aircraft 1183, 1214 and
sub, and aircraft with ASC 307¾have a pressure switch installed in the auxiliary hydraulic
system. The switch sends a discreet signal to the Data Acquisition Unit (DAU). When system
pressure is below 1500 psi and the brake pedals are depressed, this signal illuminates the Brake
Fail and Anti-skid Fail messages on the Crew Advisory System (CAS). This is assuming that only
auxiliary hydraulic pressure is available.

We have seen isolated incidences where the switch itself has failed. The DAU interprets this as
loss of hydraulic pressure and it, in return, sends the message to the EICAS. Meanwhile, the
crew is seeing normal auxiliary hydraulic system pressure indication, and they are seeing applied
brake pressure indication with pedal movement.

With engines running, this failure will not be seen, as the combined system pressure switch would
send the same message to the DAU. We are putting this information out as a possible
troubleshooting aid, in the event this situation could occur on your aircraft.
(GAC Breakfast Minutes – (12/02/97 )

BRAKE CONFIDENCE TEST

Goodyear Brake-By-Wire: Not required if aircraft has the “-3 brake” ECU or later.
Dunlop Brake-By-Wire: Not required.
Gulfstream IV Notes 25
Revision 2-98 Landing Gear and Brakes

Greg Hammerstein (GAC brake expert) recommends use of the Brake Confidence Test
after long cold soaks to circulate the brake fluid prior to use.

BRAKE TEMPERATURE MONITORING SYSTEM (BTMS)

ASC 167

Displays brake temp indications in cockpit.

Range up to 500o C/amber light above 400oc.

Selector: All -- hottest brake

LL -- LEFT GEAR, RIGHT BRAKE
LR -- LEFT GEAR, RIGHT BRAKE
RL -- RIGHT GEAR, LEFT BRAKE
RR -- Right gear, right brake

Don't take-off with amber light ON (reduced brake energy).

Test button -- selector in all position.

Needle should indicate 425-475 C (boxed area).

If light does not come on during test, one of the sensors has failed.

Isolate the failed sensor with the selector knob.

Wiring is installed in SN 1156 & subs.

100 C is normal on landing.

The SPZ-8400 Enhanced Avionics Package has integrated BTMS readouts on the EICAS
(DU 5) brake page displaying brake pressure & four temps with max temp lock in.
Gulfstream IV Notes 1
Revision 2-98 Flight Controls

15. FLIGHT CONTROLS

FLAPS
Electrically controlled/hydraulically powered.

Flap Control Valve: Opens to move flaps/closes to stop flaps (clunk heard when flaps
selected).

HYDRAULIC FLUID LOSS DURING FLAP EXTENSION

If flaps are selected up or down and then combined system fluid is lost:

It is likely that there is a leak in a flap actuator.

Because all combined fluid has leaked out before the flaps reach the selected
position, the flap control valve will remain open.

When gear is lowered, hydraulic fluid will be returned to the combined reservoir
recharging the combined system.

To stop further leakage pull Manual Flap CB (CPO top left position).

This closes the flap control valve permanently.

FLAP EXTENSION WITH COMBINED HYDRAULIC FAILURE

Flaps may be extended using the Auxiliary Hydraulic System.

Extension is three times slower than normal.

FMS monitors flap extension speed -- If too slow, disconnects the Autothrottles and
dumps. Landing Initialization.

0-10 is slow enough to meet this condition.

10-20 and 20-40 are fast enough to avoid this condition.

Flaps have priority over the Braking System.

 If the flaps are still moving on touchdown, no hydraulic pressure will be available
to brakes until flap actuation stops.
 Don't retract flaps using the Auxiliary Pump only during taxi for the same reason.
Gulfstream IV Notes 2
Revision 2-98 Flight Controls

Failure to Extend:

Overspeed Extension -- if flaps stop prematurely at above limit speeds:

Attempt to retract flaps up one notch (if flaps respond, not an asymmetry ).

Try extension again at less than limiting speed.

Flap Asymmetry --if flaps won't move when selected or stop early, it may be a flap
asymmetry problem.

To check:  Turn the Emergency Flap switch to the emergency position

 Listen for flap control valve clunk

If clunk is heard, then the flap control valve is good and there is no
asymmetry problem.

The flap control valve is disabled if an asymmetry exists.

STABILIZER FAILURE

Flaps can be extended with the Stabilizer frozen in the retracted position with no
warning.

An amber CAS message "STAB FLAP FAIL" will result only if the flaps are fully
retracted and the stabilizer is not (the worst case scenario relative to control forces).

Checklist Action: With any flap/stab failure, whether a message is presented or not, the
amber CAS Message section of the checklist must be used to trouble shoot the problem.

With the Stabilizer stuck a zero degrees and flaps lowered, expect a heavy nose-down
moment.

EMERGENCY FLAPS

The “FLAP CONT” CB (not Manual Flap Control CB) is the same as the Emergency
Flap Switch.

Gives control to the Emergency Flap System.

Manual Flap Control CB – When pulled, it removes power from the Flap Shutoff
Valve.

Emergency Flap Control will not function.

Gulfstream IV Notes 3
Revision 2-98 Flight Controls

No hydraulic pressure to the flaps is possible.

With Emergency Flap Switch selected to Emergency expect to see:

 Autothrottle system inoperative (with no flap input -- no speed bugs, with no

speed bugs -- no Autothrottles).
 AOA indicators Red-X'ed (are biased by the Normal Flap handle).
 No Vref computation (use speed bug)
 "FLAP INPUT INVALID" on the FMS CDU message line.
 Amber "STALL BARRIER 1 FAIL" EICAS message when flaps selected to
full (expect to see this on final approach so that it is not a distraction. Stall
Barrier is still functional).

Autothrottles can be regained by selecting manual V-speeds on the Display Controller.

Emergency Flap Handle out of Detent During Normal Operations

Situation:  Emergency Flap Switch -- CLOSED (normal position)

 Flap Control CB -- IN (normal)
 Emergency Flap handle -- OUT OF DETENT (abnormal)

Flaps will not move until the Normal Flap Lever is selected to a different position.

If: the Normal Flap handle is selected in the same direction that the Emergency Flap
handle is out of detent.

Then: Flaps will move to selected position of the Normal Flap handle.

If: the Normal Flap handle is selected in the opposite direction from that of the
Emergency Flap handle
Then: flaps will move in the direction that the Emergency Flap handle is displaced
and will stop full down or up as appropriate.

Example: the Emergency Flap handle is out of detent to the down position before engine
start.

Pilot selects flaps to 20 for takeoff.

Flaps move to 20 and stop as commanded (both handles agree in direction so that the
Normal Flap handle has control).

After takeoff, the flaps are selected to 10 (normal procedure).

Flaps move to full down position (39 ) (handles do not agree in direction --
Emergency Flap handle controls flaps).
Gulfstream IV Notes 4
Revision 2-98 Flight Controls

YAW DAMPER
Do not turn on until engines running.

If on slope, damper will try to compensate for perceived yaw.

Without hydraulics, will trip FGC-1 then FGC-2

(GAC Memo)

Dutch Roll Recovery -- FSI recommends that rudders be held neutral with ball centered
and work ailerons to dampen dutch roll.

YAW DAMPER FAIL INDICATION

Yaw damper fail indication only appears when electrical power to the YD system
computer has failed.

Loss of hydraulic power to the YD System will fail system with no indication.

A failed Yaw Damper will cause FGC #1 & #2 to fail if the YD switch is not selected
OFF.

RUDDER
Rudder Kick -- an uncommanded yaw of about 1/2 ball deflection, normally occurring
in the high FL 200 range during climbs and descents (feels like the rudders were kicked
and held).

Thought to be caused by one Pre-Cooler Fan Air Modulating Valve opening for
unknown reasons.

Fan air discharges from the louver beneath the pylon disturbing the airflow and
causing a yaw (kick) to the affected side.

The Precooler Valve can be electrically tested for the malfunction by maintenance.

In Flight Simulation: Turn OFF one of the Bleed Air Switches and observe a yaw to
that side after a 25 second delay (opens Pre-Cooler Valve).

SINGLE RUDDER LIMIT LIGHT

Comes on when:
Gulfstream IV Notes 5
Revision 2-98 Flight Controls

 There is no pressure in the Combined System

 The Manual Reversion Handle is unseated.
 The Fire Handle is pulled for the left engine.

If it remains on after engine start.

Recycle Manual Reversion Lever (Flight Power Shutoff Lever) full up and full down.

The MEL permits release with the Single Rudder Limit light illuminated.

GROUND SPOILERS
Six panels auto deploy to 55

Requirements for deployment:

1. Electrical control signal.

Main DC Bus power thru:

 Ground spoiler CB (CP overhead)

-- and the –

 GS arm switch armed – AND –

 Both Main Nutcracker Switches in ground mode

-or-

 Both main wheel pairs above 65 mph w/ flaps >22 or the Flap Override
Switch depressed (w/ wheel spin-up)

– and –

 Both power levers at idle

2. Hydraulic pop-up (Control) signal: Pressure from combined or utility or auxiliary

systems

3. Hydraulic power: From combined or flight systems

Hydraulics required for activation of ground spoilers:

Combined Hydraulic System alone

Gulfstream IV Notes 6
Revision 2-98 Flight Controls

-or-
Flight Hydraulic System with either the Utility or Auxillery System

Manual Deployment: Lacking the electric control signal and/or the hydraulic pop-up
signal, six boards can be manually raised to 26 using the speed brake lever if either the
combined or flight system is available.

Wheel Spin-up

Auto ground spoiler deployment will occur before or without nutcrackers in the ground
mode.

Flaps must be greater than 22 or flap override switch must be depressed.

Left wheel spin-up above 65 mph will open primary valve.

Right wheel spin-up above 65 mph will open secondary valve.

Ground spoilers wheel spin up deploy signal will remain on until 25 mph..

Ground spoilers will remain deployed below 25 mph if both nutcrackers are in the
ground mode.

GROUND SPOILER TEST

Pushing the Ground Spoiler Test Switch opens the Primary Valve allowing hydraulic
pressure to reach the Pressure Sensing Switch and the Secondary Valve.

If the Secondary Valve is properly closed, you should see the "NO GND SPLRS"
light on the center windshield post and a CAS (and SWLP) message (a function of
pressure switch) and NO boards raised.

Raised boards would indicate a faulty Secondary Valve failed or shorted open.

FLAP OVERRIDE SWITCH

Allows ground spoiler deployment on wheel spin-up with flaps less than 22.

Do not use on takeoff.

When airborne with the flap override switch selected, ground spoilers armed and gear
down with wheels spinning, pulling the power levers back to the idle stops will cause
ground spoiler deployment.
Gulfstream IV Notes 7
Revision 2-98 Flight Controls

HYDRAULIC FAILURE

LOSS OF THE COMBINED AND UTILITY SYSTEMS

Ground Spoilers will still deploy.

 The Auxiliary System provides the deploy signal

Aux pump must be selected ON, not armed
 The Flight System will power spoilers open

LOSS OF THE COMBINED, UTILITY AND AUXILIARY HYDRAULIC SYS-

TEMS

 Ground Spoilers are lost

 Speed Brakes are still available with manual deployment

Manual control, Flight hydraulic System power.

Six boards to 26 degrees (versus 52o with ground spoilers).

HYDRAULIC PRESSURE DROP NORMAL DURING SIX-PANEL SPEED BRAKE OPERATION

WITH ENGINES AT IDLE

Recently, an operator experienced what was thought to be a hydraulic pressure and indication
problem. The crew noticed a drop in hydraulic system pressure and the single rudder limit
message illuminated when they deployed ground spoilers with the engines at idle.

This scenario is normal on aircraft with six-panel speedbrakes. With the engines at idle , when the
ground spoilers are actuated, the hydraulic system pressure drops. At times, the drop is enough
to be sensed by the dual load limiter valve and the single rudder limit light illuminates. Due to the
increased volume required to operate the ground spoilers with the larger actuator (not used on
four-panel speedbrake aircraft) with the engines at idle, it is not uncommon to see the single
rudder limit light. When the engine RPM's are advanced, increased hydraulic pump output will
extinquish the light.
(GAC Service News -- July - August - September 1996)

SPEED BRAKES
No speed brakes are to be used with gear down and/or full flaps.

Results in:
 Excessive sink rate
 35 KT increase in stall speed with flaps full and speed brakes extended.
(An 18 KT increase in stall speed will occur at flaps 20).
Gulfstream IV Notes 8
Revision 2-98 Flight Controls

Use of speed brakes in this configuration will result in a red “ACFT

CONFIGURATION” message on the CAS.

Use with flaps set to 10 or 20 is permitted.

Use of speed brakes below 2,000' AGL is not recommended. (AFM 5-29)

THRUST REVERSERS
Normal deployment or re-stow time -- 2 seconds.

THRUST REVERSERS ON WHEEL SPIN UP

ASC 166 puts reversers on wheel spin up as well as nutcrackers.

Will deploy with wheel spin-up to 65 KTS before WOW Signal received or if
Nutcracker System malfunctioning.

Puts 5 second timer on Secondary Lock Solenoid -- removes one minute reverser
deploy limitation.

ASC 166A

ASC 166A allows right reverser to deploy with right wheel spin-up and the left reverser
with left spin-up.

With a cross wind and piggyback levers pre-loaded on touchdown, aircraft could
experience asymmetrical reverser deployment.
ASC 166A requires both left and right wheels to spin-up before reverser deployment is
allowed, eliminating the crosswind asymmetry problem.

Preloading reverser piggyback handles on landing is no longer allowed.

UNCOMMANDED THRUST REVERSER UNLOCK OR DEPLOYMENT

Throttle Snatch -- if doors open 37% or more, with the power levers above 620 PLA,
power levers will snatch back to idle.

Landing with TR’s deployed: Flaps 20 max.

Designed to keep the engines from going to Flight Idle (67%HP RPM) on final with a
reverser deployed.
Gulfstream IV Notes 9
Revision 2-98 Flight Controls

2nd Emergency Stow CB -- ASC 210

A second Emergency Stow Circuit Breaker (one for each engine) is installed.

This mod avoids the following situation:

A short occurs in the stow solenoid of one reverser.

This removes hydraulic pressure to the stow side of reverser.

The Un-stow Light comes on due to reverser floating.

The Emergency Stow Switch is depressed allowing a single alternate circuit to power
both reverser stow circuits.

Due to the common circuitry, the existing short in one stow solenoid now causes
the emergency stow circuit breaker and the opposite reverser control CB to pop,
removing stow power from both sides and allowing both buckets to float and set
off both unlock lights.

Try testing the reverser emergency stow switch during taxi.

REVERSER LIGHTS

White "REV UNLOCK" -- indicates one of the following:

 Primary Lock unlocked

 Secondary Lock unlocked
 Upper or lower Stow Switches unmade

Green "REV ARM" Light -- Requires both main gear Weight On Wheels (WOW) to
illuminate for pre ASC 166 aircraft and by own side wheel spin up on ASC 166 A/C.

White "REV DEPLOY" light -- the reverser doors must be fully deployed.

Reversers Not Fully Deployed

If reverser doors are not fully deployed -- max power available 60% HP.

If the doors creep from the full deploy position the piggybacks will snatch back to 60%
HP.

Secondary Lock Timer Test

APU running/generator ON.

Gulfstream IV Notes 10
Revision 2-98 Flight Controls

Engines off.

Pull back on piggybacks.

Should see reverser unlock light ON.

Five seconds later -- unlock light off.

Unlock light is due to secondary lock being energized.

Use caution not to keep piggybacks out of stow for more one minute on non-ASC
166 aircraft.

Thrust Reverser Test Requirement

Q - We received a GIV AFM revision concerning operation of the thrust reverser before/during
taxi. Our crew looks at the thrust reverser doors during preflight. If the doors aren’t sagging, they
know that the secondary locks are closed. If they deploy the T/Rs during taxi and restow them,
the only guarantee is that hydraulic pressure is holding the actuator closed. I think Gulfstream is
doing the operators an injustice by adding this AFM requirement. There is no guarantee that the
T/Rs will work the next time they are operated. How can we go to the FAA and get a release on
that portion of the AFM?

A - The Preface to the AFM (Page 0-1) states that the only section an operator must comply with
is the Limitations in Section 1. The procedures in Sections 2, 3, and 4 are "..only for guidance in
identifying acceptable operating procedures and are not considered mandatory or in any way
construed as prohibiting an operator from developing his own equivalent procedures." The key
here is that the operator must have his own equivalent procedure.
(GAC Breakfast Minutes – 7/28/98)

PINNING REVERSERS

There is now an approved way to pin reversers closed for flight.

No ferry permit required with MEL -- can carry passengers.

There are pins in the hell hole to pin actuator valves to neutral.

Secondary locks are bolted in the locked position.

When actuator valve pinned, no stow pressure is maintained.

Reversers will float slightly at high power settings causing a possible

"REV UNLOCK” light.

Disconnect cannon plug's to eliminate lights.

Gulfstream IV Notes 11
Revision 2-98 Flight Controls

New Temporary TR Lockdown Procedure/Hardware

New procedures, hardware and placards have been developed to improve the existing temporary
lockdown procedure for the GIV thrust reverser doors.

Information will be published in Maintenance Manual Rev 25.

Lockdown kit, P/N 1159CGSK78000-1, provides all special tools and hardware to lock down
one thrust reverser system for any malfunction.

Kits are in short supply.

Specify if ASC 45 has been incorporated for aircraft 1000-1040

(GAC Breakfast Minutes -- 02/08/94)

GIV - NEW THRUST REVERSER LOCKDOWN KIT IS AVAILABLE

Gulfstream has developed new tooling to lock down a GIV thrust reverser in the event of a
jammed actuator. There are now two GIV thrust reverser lockdown kits. Kit 1159CGSK780000-1
provides all special tools and hardware to lock one reverser system for any malfunction except a
jammed actuator. The1159CGSK780000-3 kit includes everything in the -1kit plus the necessary
tools and parts to remove a jammed hydraulic actuator in order to dispatch the aircraft. The
additional parts in the -3 kit are a turn-buckle rod (P/N 1159SEP40003-27) and line caps (P/N
AN929L6J). These extra parts supplied with the -3 kit, when used with parts in the -1 kit, will allow
the creation of an 1159SEP40004-19 turnbuckle assembly. The rod ends from the jammed
actuator will be used.
Gulfstream is manufacturing turnbuckle assemblies P/N 1159SEP40004-19 (includes turnbuckle
rod (-27), turnbuckle barrel, and rod ends) that will be available for rent or sale. This option is for
operators who desire a ready-to-go, complete turnbuckle, without having to assemble the unit at
the time of a jammed actuator. This will allow an easier installation for personnel not fully familiar
with the GIV and a quicker aircraft dispatch. Contact Technical Operations at 912-965-3241
(phone) or 912-965-4184 (fax) for technical information about the kits. Contact Spares at 912-
965-3268 (phone) or 912-965-3685 (fax) for the kit or turnbuckle assembly price and availability.
(GAC Breakfast Minutes –09/30/97)

GIV — MOL Released on Engine T/R Door Lockdown Tools

Gulfstream released a Maintenance and Operations Letter (MOL) to GIV operators on August 4,
1998 to replace the lock keys on the engine thrust reverser (T/R) door lockdown turnbuckles. The
lock key configuration was found to not engage properly. Gulfstream Publications will be revising
the Thrust Reverser - Temporary Door Lockdown procedure and illustrations within the
Maintenance Manual and update the IPC, Chapter 12. Material Services will be shipping new
locking devices to all operators who have purchased parts or kits from us.

Once your MOL is received, should you have any questions or comments, please direct them to
Technical Services at 912-965-3241 (phone) or 912-965-4184 (fax.)
(GAC Breakfast Minutes – 8/4/98)

Engine Start with Deployed Reversers

If thrust reverser(s) deployed before engine start, starters locked out.

Gulfstream IV Notes 12
Revision 2-98 Flight Controls

Engine start is prohibited if either "REV UNLOCK" white light is ON.

Both engines are start inhibited.

In this case:

 To bypass lockout, pull Warning Lts - Power #4 (Left Reverser) & #8 (Right
Reverser) on pilot's CB panel in warning lights area (This kills the lights and
fools the system into lifting inhibition)
 Crank (not start) the engine for 15 seconds
 Push in CB's, if light out -- stop cranking
 Wait for 3 minutes -- then do a normal start

To Service Reversers:

This procedure is not required w/ ASC 166.

 Locate left and right Secondary Lock CB's on pilot's panel

 Power system with a mule
 Open doors and immediately pull Secondary Lock CB's
 Leave out until ready to stow reversers

This procedure is required because of one minute limitation on secondary lock

solenoids being powered.

TAXI WITH REVERSERS DEPLOYED

Ok with ASC 166 modified aircraft.

Watch for FOD’ing of engines.

Indications:  Dust/debris blowing forward of A/C

 Increase of OAT or TGT (gas recirculation)

MANUAL REVERSION

Turn off the Yaw Damper before pulling the flight power shutoff handle up.

Failure to do so will result in both FDCs going offline in sequence.

The FDCs compare the signal sent to the yaw damper with the resulting rudder
displacement. If these don’t match, the FDC fails itself, and selects the other
FDC which does the same.
Gulfstream IV Notes 13
Revision 2-98 Flight Controls

To get the FDCs back, pull both CBs and select the yaw damper OFF. Reset both
FDC CBs.

WINGS

LEADING EDGE SEALANTS

Between wing leading edge sections (gap band seal) is a gray sealant.

It must be in place and very smooth.

Missing or deformed sealant can raise stall speed significantly.

Gulfstream IV Notes 1
Revision 2-98 Avionics

16. AVIONICS
GENERAL
PUBLICATIONS

FMS Technical Newsletter

Very good information for pilots, published twice a year.

Address: FMS Product Support

Division: AV/2G19A4
Honeywell, Inc.
Business and Commuter Aviation Systems
P.O. Box 29000
Phoenix, AZ 85038-9000

You must use company billing address for receipt -- Honeywell will not send issues to a
home address.

Phone: 888-TALK FMS (888-825-5367)

602-436-7700
Email: fms-product-support@cas.honeywell.com/bcas

In addition to traditional mail subscriptions, the current and past issues of the FMS
Newsletter may be accessed at the Honeywell web site located at:

http://www.cas.honeywell.com/bcas.

The Publications Distribution Department also handles pubs for SPZ-8000, FMS, TCAS,
radar and lightning detection. They may be reached at:

602-436-5530 or through the Honeywell web site.

FLIGHT MANAGEMENT SYSTEM (FMS)

The FMS is a system comprised of Control Display Unit (CDU), a Navigation Computer
(NZ) and a Performance Computer (PZ), with navigation information received from dual
Honeywell Inertial Reference Systems (IRS) and the Collins VHF Navigation and DME
systems. Optional dual 12 channel GPS receivers are available. The entire system is
designated an FMZ-XXXX.
Gulfstream IV Notes 2
Revision 2-98 Avionics

HARDWARE
The hardware portion of the FMS consists of four components:

1. Control Display Unit (CDU)

2. Navigation Computer (NZ)
3. Performance/Autothrottle Computer (PZ)
4. Data Loader (DL)

SOFTWARE
The software portion of the FMS consists of two programs:

 Navigation Program (NZ-XXXX)

 Performance Program (A-PZ-XXXX)

Current FMS versions in GIV service:

Nav System Navigation Performance Software

Software Version Version
FMZ-9101 NZ 9101 PZ 9401 software
FMZ-2000 NZ4.1 PZ 9402 software

SOFTWARE VERSION -- FMZ-800 FMS

NZ-9401 SOFTWARE UPGRADE

Next in sequence after NZ-9302 (94 = Year, 01 = customary designation for GIV
software)

Final software release for NZ-9101 (Intel 8088 CPU based computer) series.

From 1.28MB to 1.8MB memory

Memory capacity limited by Intel 8088 processor used in the nav computer

NZ-9401 NEW FEATURES:

 Runway place/bearing/distance fixes

Gulfstream IV Notes 3
Revision 2-98 Avionics

 Crossing points relative to active waypoint

 Stored non-precision instrument approaches
 Designed to allow a GPS precision approach
 Equal time/equal distance waypoints
 Stored flight plan ground speeds changeable
 Holding patterns in stored flight plans
 255 flight plan storage capacity
 Allows custom database to be up/down loaded to disk for backup/transfer
 Includes all AFIS interfaces (AFIS may be installed but is not a part of upgrade)

Designated Crossing Points: NZ 9401 will allow designated crossing points along a
route to be entered simply by entering:

"SAV//50" for a fix 50 NM out of PBI along the route to SAV

If the point is entered in the FMS route list before SAV (i.e., placed on SAV in the
waypoint list), the point will refer to 50 miles short of SAV

If the point is entered after SAV, it will refer to a point 50 miles beyond SAV

The dogleg problem has been eliminated

SOFTWARE VERSIONS -- FMZ-2000 FMS

NZ4.1

Represents a major upgrade to the FMS System bringing it up to the computational and
memory requirements of GPS approaches.

No obvious physical change to the FMS Control Heads.

Latest Navigation Software Version:NZ4.1D (New name format)

NZ4.1 comes with GPS approach capability and authorization.

Latest Performance Software Version: PZ-9402

ASC 349 modifies existing GIV's to the NZ-2000

NZ4.1 NEW FEATURES:

 Memory increased from 1.28 megabytes to 4.0 megabytes

 The computer processor upgraded to the faster Intel 386 CPU.
 Weight and size is decreased.
 Improved ETA & fuel predictions.
Gulfstream IV Notes 4
Revision 2-98 Avionics

 "Min" EPR now called "Rated" EPR.

 AFIS messages now pilot selectable to VHF or satellite stations for more
economical use (AFIS is not a standard component of the FMS-2000 System but
it may be integrated into it).
 Oceanic waypoint shorthand entries are back (i.e., 4060N).
 ETP/Point of No Return now calculated automatically.
 Will eventually be certified for 100% GPS source navigation.
 Is certified for stand alone GPS approaches (NZ4.1 software)
 Navigation database will contain all precision/non-precision approaches.
 Uses new Autothrottle Computers for better VNAV control (limited to a ¼ "G"
maximum versus the old ½ "G" limitation for smoother operations).
 Maximum number of stored flight plans increased from 100 to 250.
 Maximum number of waypoints per stored flight plan increased from 50 to 100
w/p's.
 Maximum number of pilot defined waypoints increased from1200 to 2500 w/p's
 The Custom Database is now uploadable/downloadable to the Dataloader for
backup and data transfer to other aircraft.
 Can change selected runways in FMS without affecting initialization.
 Runway end fixes can be brought directly to the scratch pad for rapid creation of
runway offsets.
 Pilot designated fixes can be placed at set distances before or after existing flight
plan waypoints rapidly without the old "doglegging" problem.

On aircraft having SPZ-8000 systems with the NZ-2000, a flight panel annunciator and
associated wiring will be added. Aircraft with the SPZ-8400 systems will require wiring
additions for CAS display of FMS approach messages.

“D” MODIFICATION

The latest update to the NZ4.1 FMS software is mod “D”.

This update provides fixes for many of the software glitches associated with previous
versions.

Position Initialization Problem --On principal fix is the problem associated with
entry of lat/longs that end in numbers between 59.5-59.9 minutes inclusive.
Previous versions would not accept position initialization with lat/longs ending in
these numbers. NZ4.1D fixed this problem.

NZ5.0

NZ-2000 Upgrades to Honeywell Update NZ5.0

The NZ-2000 upgrade to software version NZ 5.0 includes a change to the 586 speed processor
(commonly known as the Pentium® processor). The speed change will support future growth
Gulfstream IV Notes 5
Revision 2-98 Avionics

requirements, such as Global Positioning System (GPS) precision approaches and better
database memory management. With better memory management, increased memory is
available. Available memory will jump from four megabytes to 16 megabytes.

A jump from four to 16 meg of memory may seem negligible. In 1995 when the NZ-2000
originated, the whole worldwide database could be contained in about 2.5 meg of memory. At the
time, four meg seemed like a reasonable capacity for growth. However, with the addition of
standard instrument departures, approach terminal routes, and the world growing everyday, as
far as transportation goes, the database was bumping up against that edge of four meg. Sixteen
meg offers much growth.

A welcome benefit of the processor and memory upgrade will be the simultaneous and fast
download of your NAV database disk. Anyone who has loaded a database disk can attest to the
fact that it is a long process. If you have three flight management systems (FMSs), the demand
time will drop from about 90 minutes to about 12 minutes.
(GAC Breakfast Minutes – (01/20/98 )

NZ5.0 Upgrade

We would like to announce the latest FMS upgrade - NZ5.0. This hardware upgrade includes the
addition of a Intel PentiumTM processor as well as increased memory capacity for the FMS. This
upgrade will allow for future growth and provide the capability to add additional features. NZ5.0 is
available for both Primus 2000 and NZ-2000 systems.

Features of the NZ5.0 include the following:

 Navigation data base size has increased from 4 Mbytes to 16 Mbytes.

 Simultaneous navigation data base loading to all FMS on the aircraft.
 Terminal Area Speed Targets allows the pilot to define the speed targets for terminal area
operations.
 Automatic transitions (such as BOD sequence) from path to pitch hold (currently, the system
transitions to flight level change).
 8.33 kHz Comm Tuning from CDU.
 Easy FMS initialization to GPS Position.
 VHF Datalink tuning for Honeywell Satellite Landing System.
 Capability to select the active flight plan from multiple flight plans on a 3.5" floppy
disk.
 Ethernet capable for future navigation data base loading.

NZ5.0 requires a new version of navigation data base. Current versions are not compatible with
NZ5.0. For additional information regarding navigation data base information, refer to question 11
of the Question & Answer section of this newsletter.

Lead times for NZ5.0 is approximately 30 days.

(Honeywell FMS Technical Newsletter – March 1998)

NZ-2000 v5.0 Available Second Quarter 1998

A recent Honeywell sales bulletin indicated that version 5.0 was available for the NZ-2000 Flight
Management System (FMS). However, this will not be available for Gulfstream aircraft until late in
the second quarter 1998.
(GAC Breakfast Minutes – (02/03/98 )
Gulfstream IV Notes 6
Revision 2-98 Avionics

Q: What is the status of the NZ-2000 Version 5.0 FMS software for the GIV retrofit? When will it
be available?

A: We have targeted production aircraft S/N 1360 to incorporate that software. There will be an
Aircraft Service Change (ASC) amendment to the NZ-2000 ASC for the earlier aircraft, that will
allow the upgrade to version 5.0 software. We are targeting an aircraft for test in the Completion
Center during the summer months. We anticipate August availability, but have to get a
Supplemental Type Certificate (STC) amendment or an ASC amendment in order for approval.
(GAC Breakfast Minutes -- 03/24/98)

The GIV version of NZ5.0 upgrade expected to be available in April 1998 at a cost of
$8,000.
(Ken Farthing – GIV Recurrent Class)

The GIV version of NZ5.0 upgraded expected to be available in Oct. 1998.

(Dave Dwyer, Lead FMS Engineer, Honeywell)

Question: When I upgrade my FMS to NZ5.0 (or later software version), will it be necessary to
update/modify the information Honeywell has on file with the Navigation Database distribution
group?

Answer: Yes. Although your FMS should initially be loaded with the correct FMS Navigation
Database by the company doing the installation, it is necessary to inform Honeywell of the
change to your FMS hardware, so you can be supplied with the correct version of the Navigation
Database. The NZ5.0 (or later software version) upgrade to the FMS will require a Version 3
database, which is currently not used by any other Honeywell FMS. Your FMS information on file
should be updated by contacting the Honeywell Navigation Database group via fax (602-436-
4411) or phone (602-436-4313). This information should be provided to Honeywell as soon as it
is available to avoid receiving the incorrect Navigation Database version for the installed FMS.
Note that if one attempts to load the incorrect Navigation Database version, the FMS will display
the scratchpad message "CHECK DATA LOAD (3E)". This indicates "Wrong Nav version on
disk". The FMS cannot be loaded with the wrong Navigation Database.
(Honeywell FMS Technical Newsletter – March 1998)

COMING FEATURES

Here is a brief description of new features currently under development. Note that these features
will require the Pentium™ FMS card (software version NZ5.0 or higher). Additional details about
availability and pricing will follow at a later time.

1. A default of 000T/00 CRZ WINDS on the PERF INIT pages so entry is optional instead of being
required.

2. The addition of displaced threshold, slope, and runway width when a runway is displayed on
the WAYPOINT LIST Page.

3. Default of the RADIO TUNE page is changed to be select previous instead of deselect
previous frequency.
Gulfstream IV Notes 7
Revision 2-98 Avionics

4. Provide easy access to runway data when displaying an airport on the WAYPOINT LIST page.
A RUNWAY prompt will be displayed on the last page of the airport data to allow access from the
airport data directly to the airport runway data.

5. The ability to save the ACTIVE FLT PLAN following creation of the flight plan.

6. Allow entry of airways using the entry format start.airway.end.

7. Allow entry of altitude constraints with temporary waypoints (P/B/D/ALTITUDE, P/B/P/B/

ALTITUDE, P//D/ALTITUDE, etc.).

8. Provide a units conversion page (pounds/kilograms, Fahrenheit/Celsius, gallons/liters, knots/

meters per second, feet/Flight Level/meters, weight/volume, Nautical Miles/Kilometers,
QFE/QNH).

9. The ability to load waypoint wind/temp data from AFIS or PC flight plans and store the data
automatically into the PERF PLAN pages.

10. Provide a PRINT prompt on AFIS pages to allow on-demand printing of AFIS data.

11. Provide the ability to output the FLIGHT SUMMARY data to printer or floppy.

12. Synchronization of the FMS clock and date to GPS clock and date.

13. The introduction of PC Data Loader (PCDL). This new product consists of using your laptop
computer (any Windows 95 or NT capable laptop computer will work) and an Ethernet PCMCIA
card (available from any computer store) to download the navigation data base to the FMS. The
current NZ-2000 download time (approximately 10 minutes for 4 Mbytes) is dramatically reduced
(approximately 40 seconds for 4 Mbytes).
(Honeywell FMS Technical Newsletter – September 1998)

HONEYWELL COMPUTER BATTERY REPLACEMENT

PZ-800 The PZ-800 Performance Computer battery has a five-year life cycle. You may access
information on the time remaining on this battery by going to the maintenance test (perform the
Performance 1- or 2-Status Test). The test will display the battery status as “OK,” “Low,” or
“Dead.” This battery also must be replaced by Honeywell.

NZ-2000 The newer NZ-2000 NAV computer battery, which is line replaceable, has a two-year
life cycle. Replacement is accomplished at the field level, by following the instructions in the
Gulfstream Maintenance Manual, Section 34-02-00. The computer includes a placard from
Honeywell to reflect the battery change due date. On the CDU, you will get the following message
two months before the battery’s expiration: “FMS battery maintenance required.”

If the battery dies, the NZ-2000 is still usable in flight but the custom way points will be lost.
However, you can build a manual flight plan. Honeywell provides sufficient warning to change this
battery. You will want to either download your custom database to disk or cross load your
database before you change the battery (to ensure data is not lost). Then when you get the new
battery installed, cross load the database back into the computer with the new battery; then
replace the other computer’s battery.
(GAC Breakfast Minutes – 5/12/98)
Gulfstream IV Notes 8
Revision 2-98 Avionics

FMS CDU HAS MULTIPLE FAILURES, CONFIGURATION CODES WRONG

A GIV operator reported that during a recent flight the Flight Management System (FMS) Control
Display Unit (CDU) indicated multiple failures of the Very High Frequency Omnirange
Navigation/Distance Measuring Equipment (VOR/DME). While the crew was trying to fill way
point information into the scratchpad, the failures would overwrite and the crew would have to
delete them. Although the failures indicated on the CDU, the navigation displays showed correct
bearing information [Horizontal Situation Indicator/Dual Digital Remote Magnetic Indicator
(HSI/DDRMI)]. Considering this information, the maintenance crew did some troubleshooting.
Thinking they had a configuration code problem on digit 14, they tried to change the code but did
not clear the problems.

On further investigation they found that the Collins Radio Tuning Unit (RTU) codes had been
modified for 8.33 kHz spacing. The previous configuration was for the 12th digit to be a “3.” On
further investigation they found that the 12th digit had to be a “D.” The installation manual did not
instruct them to set to “D” on that code. The installation manual is being reviewed for clarity and
an update to the configuration code tables.

Once the operator changed the configuration code for the Collins RTUs, they returned the aircraft
to normal system operation.
(GAC Breakfast Minutes – 9/1/98)

NDB DATABASE
CAPACITY
NZ-9401 NZ4.1

Database Memory 1.75 4.0-8.0

Number of Disks
per Revision 8 6
Maximum Waypoints 60,000 120,000+

Worldwide Database Yes Yes

SIDS/STARS Yes Yes
Jet Routes All All

Victor Airways All All

Intersections, High All All
Intersections, Low All All

Airports ICAO All*

Runways >5000' >4000'*
Worldwide Approach
Procedures None None All

* -- Some low altitude waypoints are being removed from the database due to database
space limitations. A new two region database version is now available (as of March
26,1998) for operators that need better regional coverage. See the following section.
Gulfstream IV Notes 9
Revision 2-98 Avionics

If the NZ-2000 update is not in your plans for the immediate future, Honeywell has an option to
take steps so that they do not exceed the four meg requirements. The operational impact will be
as follows:
• The database will now come in three sets of disks.
• The NZ2West set, which will be about five disks/set, will cover North America, South
America, Western Europe, and parts of North Africa.
• The NZ2East set will cover an area roughly including Eurasia, Africa, Australia, the
Pacific region, and the extreme west coast of North America.

• The WORLD2 database is available for those who fly on a worldwide basis. With this set,
Honeywell will delete non-essential and non-compulsory way points. Essential way points are
those that cross an intersection, or cause a direction change in the airway. Compulsory way
points are mandated way points which you have to report to air traffic control (ATC). Also deleted
from this set are terminal procedures with a runway length less than 3,000 feet.

As the database continually grows, there may be a need to shrink the database even farther. The
stream-lined database does have a reduction protocol in effect, and that can be best explained by
your Honeywell representative.
(GAC Breakfast Minutes – (01/20/98 )

WHEN TO USE A REGIONAL DATA BASE?

Due to memory limitations with the NZ-2000 worldwide navigation data base, there is an
increasing need for operators to use regional data bases. For NZ-2000 operators, there will be 2
regional data bases introduced with WORLD2-204 cycle (effective date is Mar 26, 1998). This will
split the world into two regions. The West regional data base will identify the western hemisphere
(for U.S.-based operators). The East regional data base will identify the eastern hemisphere.
Boundaries may vary depending on the navigation data base version and there is some overlap
between the regions to allow for trans-Atlantic crossings.
(Honeywell FMS Technical Newsletter – March 1998)

DATABASE UPDATES

Each update disk set stands alone

Gulfstream IV Notes 10
Revision 2-98 Avionics

Skipping an update does not affect completeness of latest update (if updates fall behind --
need not be updated sequentially to become current, just load latest update)

For problems/questions on the database, contact Lou Selk (Honeywell) 602-436-7110,

fax 602-436-7100

The FMS upgrade NZ5.0 will increase the database capacity and allow the full world
coverage to be loaded.

Three high density diskettes are required to update the NDB database.

Navigation Data Base (NDB) Diskettes Are No Longer Colored

Honeywell’s supplier for NDB diskettes is no longer providing colored diskettes. All future
diskettes will be black. This change is scheduled to occur prior to the end of year. To assist in the
identification of an appropriate set of diskettes, Honeywell will color code the labels of the
diskettes. Previously, all diskette labels had black and red ink. The new labels will use black ink
and the color of ink as defined by the following:

THWORLD-9XX, 920WEST-9XX, 920EAST-9XX: Royal Blue Ink Labels (Formerly Blue Disks)
NZ2WEST-2XX, NZ2EAST-2XX, WORLD2-2XX (Low Density Disks): Black Ink Labels (Formerly
Black Disks)
NZ2WEST-2XX, NZ2EAST-2XX, WORLD2-2XX (High Density Disks): Light Blue (Formerly Light
Blue Disks)
WORLD3-3XX (Low Density Disks): Pink Ink Labels (Formerly Pink Disks)
WORLD3-3XX (High Density Disks): Purple Ink Labels (Formerly Lilac Disks)
(Honeywell FMS Technical Newsletter – September 1998)

Floater Waypoints

Honeywell has been removing non-essential waypoints from the NDB database to make
room for the rapidly growing number of instrument SIDs, STARs and IAPs. The
waypoints that are being removed are called floaters. The following is a description of
floaters:
Floaters are those waypoints that are not associated with any SIDs, STARs, or airway
procedures. These include all non-essential and non-compulsory waypoints, as determined per
ARINC 424 coding rules. An essential waypoint is any waypoint (not navaid, airport, or runway) in
terminal procedures or any waypoint (not navaid) in enroute airways, required for navigation.
These may include changes in bearing, intersections of two airways, or a beginning or an end of
a continuous segment. A compulsory waypoint is any waypoint (including navaid) on an enroute
airway at which a "position report" must be made to the appropriate ATC unit.
(Honeywell FMS Technical Newsletter – March 1998)
Gulfstream IV Notes 11
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CUSTOM DATABASE CAPACITY

NZ-9401 NZ4.1

Flight Plans 255 255

Waypoints (All Flight Plans) 2,435 2,434
Waypoints/Flight Plan 50 100

FMS LOCKUP -- Rare occurrence

If it does occur, it might be cleared using the following technique:

1. Transfer the custom database from the operating FMS to the locked up one.
2. After the transfer is approximately 10% complete, abort transfer.
This should unlock the FMS.
3. Transfer the full custom database again from unaffected FMS.

Clearing the Custom Database -- Will clear all custom waypoints and stored flight
plans

To clear:  Select Maint Page 2

 Place "CF" (clear files) in 4l

PERFORMANCE COMPUTERS (PZ)

PERFORMANCE COMPUTER UPGRADES

Nav computers designated “NZ-XXXX” (NZ-9401 & NZ-2000 current)

Perf computers designated “PZ-800-XXX” (PZ-800-925 current on the FMZ-2000
system)

Software designated A-PZ-9XXX (A-PZ-9402 current for both systems)

(F-PZ-9XXX denotes the Canadian version of the software.)

There are currently three versions of the performance computer (hardware & software)

 Dash 910 (-910) Baseline GIV performance only

 Dash 920 (-920) GIV SP & ASC 190 performance only
 Dash 925 (-925) FMZ-2000 system (AFM 5-105, 5 JAN 96)
 Dash 930 (-930) Used with NZ-9401 FMS software configurable to the baseline
or SP equivalent GIV’s
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DASH 920 PERFORMANCE COMPUTER

Available for GIV SP's and GIV's modified with ASC 190 (SP mod) or ASC 266 (IP mod -
increased weights) and included on SN 1214 & sub

Designated A-PZ-9401 for US rules aircraft (found on page one of Perf Initialization page on
FMS)

CHANGES:

Eliminate the Perf 1 & 2 failures that intermittently cause Autothrottle disconnects

New control law for speed targets in the terminal area

 Maintain 250 KTS until 15 track miles from destination

 At 15 miles, clean configuration, speed target changes to 200 KTS or Vref + 10
whichever is higher
 Flaps 10o, speed target is 180 KTS or Vref whichever is higher
 Flaps 20o, speed target is 160 KTS or Vref whichever is higher
 Flaps 30o, speed target is Vref +10 not to exceed 180 KTS/ASC 190 A/C or 170 KTS
ASC 266 A/C
(GAC Breakfast Minutes -- 02/01/94)

PERFORMANCE COMPUTER 1 FAILURE

Failure of Performance Computer 1 causes the pilot flying to lose V-speeds and vertical
navigation capability.

To regain V-speeds, FMS #2 must be selected on the Captain's side.

TWIN PERFORMANCE COMPUTER FAILURE

Can release with both Performance Computers failed using the Master MEL List.

Will have no:  Autothrottles (They require computed EPR's)

 Auto V-Speed computation
 Auto Gear Horn Inhibit (muting)(requires autothrottles to function)

Autothrottles can be engaged using manually set V-Speeds

Takeoff performance data (EPR's, V-speeds and distances) can be found in the FSI GIV
Checklist Performance Section in the back of the checklist (pages “P-xx”)

DATA LOADER
A 3 ½ “ floppy disk drive used to load NDB database data, custom database data, AFIS
computer flight plans and weather data and unload maintenance data.
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There are two data loader models:

DL-800 – A large square faced uint with one button and one rotator knob. It uses low
density 720 kb floppy diskettes only (the diskettes with only one square hole cut in the
top edge of the diskette.)

DL-900 – A low profile rectangular face containing two buttons only. It can read and
write to low density 720 kb or high density 1.44 mb diskettes (the high density disk holds
twice the amount of data and has two square holes cut near the top edge of the diskette.)

REQUIREMENTS FOR HIGH SPEED NAVIGATION DATA BASE LOADING

This requires both an FMS update and a data loader update. Software versions NZ4.1 mod D,
NZ4.3, NZ4.5 mod A, as well as all subsequent versions support this change. The DL-900
requires mod C to support the change. Note that the DL-800 can not support the data loading
improvement.
(Honeywell FMS Technical Newsletter – Summer 1997)

DATA LOADING PROBLEMS

If you encounter problems while loading your NDB, there are a few steps you can try prior to
calling the FMS Product Support Group. Loading can be attempted again after each step. Before
conducting any of the following steps, note the CDU scratchpad message which is displayed and
compare it to the Maintenance section of your FMS Pilot’s Operational Manual. If the message is
related to communication/interface issues between the data loader and the FMS, the following
may alleviate the issue:

1. If the heads of your data loader have not been cleaned for some time, it is important to run a
3.5” disk cleaner through the loader. Place the cleaner disk in the data loader and turn the unit
on, then off, and repeat several times.

2. If operating a DL-800 model of data loader, try cycling power on the unit several times and
attempting loading again.

3. Turn off any units not required for the NDB loading, especially the DMEs and anti-ice heaters.
Note that cross-loading the NDBs between the FMSs requires that the EFIS (and in some cases
the Flight Directors) be powered to act as bus controller. If the message is associated with the
NDB diskettes (according to the FMS Pilot’s Operational Manual), the following may assist in
isolating the issue:

1. Attempt to load the same set of disks a second time and note if the loading fails at the same
point.

2. Attempt to load another region from the same cycle of disks, or a set of disks from an old cycle
if no other disk sets are available for the current cycle.

3. NOTE: DO NOT ATTEMPT TO LOAD THE NDB INTO YOUR SECOND FMS, IF THE
LOADING PROCESS RESULTED IN AN INVALID NDB ON THE FIRST FMS. If attempted, it is
possible that both FMSs will have invalid NDBs. If an FMS contains an invalid NDB, it is locked
Gulfstream IV Notes 14
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on the DATA LOAD pages and thus can not be used in flight. Should this occur, it is best to
crossload the good NDB from the second FMS into the first FMS with the invalid NDB.
If the message has a code 3E, the wrong NDB version for your FMS is on the disk you are
attempting to load. This could happen if your FMS has been upgraded to new software and the
Honeywell Navigation Data Base personnel were not made aware of the update. Note that
operating software NZ5.0 requires a different NDB than NZ4.x (or earlier software) due to the
NDB memory increase. If you have updated your FMS and/or have received a 3E code, please
contact the Navigation Data Base group at 602-436-4313 or the FMS Product Support group at
602-436-7700 (1-888-825-5367, U.S. and Canada) to receive the appropriate NDB. For more
information and assistance in trouble shooting a NDB loading issue, please contact the FMS
Product Support group at 602-436-7700 (1-888-825-5367, U.S. and Canada).
(Honeywell FMS Technical Newsletter – September 1998)

Q - The Honeywell DL-900 data loader Mod C is working nice. If you want to save about 20
minutes on each data loading, get the mod. However, there have been two data loading
problems that I have not seen addressed.

1) The data base is not changing properly on the cycle change.

2) If you do not have a custom waypoint in the custom data base, you will stay in single operation.
This is one of those “gotchas” on the ramp. Can Honeywell address this?

A - 1) Data base - Honeywell is aware of the data base not rolling over. We are working on the
source, but have not found out what is wrong. When we identify corrective action, we will include
that in an NZ software update.

2) Custom waypoint - This is a condition not previously known to the Savannah Honeywell office.
It has been added to the list of potential 4.1D software problems to be addressed.
(GAC Breakfast Minutes – 04/15/97)

Bad Disks – Most common causes are due to bad disks, excess noise on the data transfer line,
and dirty heads in the data loader unit. To minimize the effects of these factors, handle the disks
with the care necessary for an Electro-Static Discharge (ESD) sensitive device. Check the data
loader wiring to ensure proper shielding. Finally, clean your data loader heads with a
commercially available disk drive cleaner. At a minimum, heads should be cleaned on an annual
basis.
(Honeywell FMS Technical Newsletter – Summer 1997)

USING HIGH DENSITY DISKS FOR LOADING THE NAVIGATION DATA

BASE (NDB)?

In order to use high density disks for loading the NDB, it is necessary to have a DL-900 Data
Loader. If you have a DL-800 data loader and are interested in upgrading to a DL-900, please
contact your local Honeywell sales representative or Honeywell FMS Marketing Manager, Vince
Sadd (602-561-4712 or vince.sadd@cas.honeywell.com). If you currently have a DL-900 and
would prefer to receive high density disks for loading your NZ-2000/IC-800 NDB, please contact
Kelly Martinez (602-436-4313) or the FMS Product Support Group (1-888-825-5367 or 602-436-
7700) with your company information. High density diskettes are available for Version 2 and 3 of
the NDB. Version 2 NDB is required for NZ4.x (where x represents a number between 1 and 9)
and Version 3 NDB is required for NZ5.x.
(Honeywell FMS Technical Newsletter – September 1998)
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AUTOTHROTTLES
Rely upon Performance Computers for EPR signals

Failure of Performance Computer #1 will disable the autothrottles and V-speeds.

To regain autothrottles:

 Select nav source to FMS 2 (uses PZ-2)

 Reselect Autothrottle 1

THROTTLE CLAMPING (HOLD)

Always double check that the target EPR has been set to avoid the possibility of early
throttle clamping (boxed hold indication on both PFD's) at a lower power setting.

Clamping occurs at 60 KIAS (airspeed not ground speed)

Premature clamping can occur at less than target EPR with a slow power lever
advance or with high headwinds where 60 KIAS is reached rapidly.

REQUIREMENTS FOR AUTOTHROTTLE ENGAGEMENT:

1. Autothrottle armed
2. Takeoff Mode ("TO") selected on Flight Director (Go Around Button)
3. Isolation Valve closed (electrically locked out)
4. Systems actually set as programmed in T/O Initialization (to get V-speeds):
 Flaps
 Anti-Ice
 Anti-skid
 Ground Spoilers
5. EPR  1.17 and less than 20% EPR split

Note: Autothrottles may not be used with Wing Anti-ice -- ON due to the Wing Anti-ice
Cross-Bleed tube that connects the two sides of the bleed air manifold. The two
sides must be isolated in order for Autothrottles to work properly. This is also the
reason why Autothrottles are not permitted (cannot be used) when the Isolation
Valve is open.

Note: A failed Performance Computer will inhibit Autothrottle engagement.

AUTOTHROTTLE HUNTING
Gulfstream IV Notes 16
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At high altitudes in turbulence or OAT changes, A/T's may hunt for correct power
setting, moving up and down

Fix:  Disengage A/T's and set manually to the green carrot indicators, or as
necessary.
 Re-engage A/T's when turbulence is reduced and OAT stable.

AUTOTHROTTLE DESCENTS

The minimum power lever angle (PLA) in an autothrottle descent is 8 to 12

depending on altitude.

It used to be set to 2 degrees but this resulted in constant autothrottle hunting

up and down.

This high min PLA can result in excessive airspeed in fixed rate and fixed
angle (VNAV) descents with autothrottles engaged.

FMS AREA NAVIGATION

Blue "CHECK POS SENSOR" -- one of the IRS's is more than 10 NM away from the
FMS position

If one of three IRS's is more than 30 NM from the FMS position, it is automatically
deselected from position blending

Can find out if an IRS is being used by checking the sensor page

A "U" by the position readout indicates that the IRS is being Used by the FMS for
position blending or comparison.

If operating with only two installed or operating IRS's, auto deselection will not occur
when one IRS has drifted more than 30 NM.

In addition, if the aircraft is GPS equipped, the GPS sensors will automatically be
deselected from use.

The pilot must evaluate the IRS's and manually deselect the misbehaving IRS.

The GPS sensors will automatically be reselected after a four minute delay, once the
bad IRS is manually deselected.

Do not manually deselect all IRS's when navigating on IRS's and GPS's only
Gulfstream IV Notes 17
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It is not legal to operate only with reference to GPS sensors and it does not
significantly increase accuracy.

With NZ4.1 software, the GPS position input is weighted 100% with the IRS inputs
used for comparision.

HOLDING PATTERNS

HOLD AT PRESENT POSITION

Enter: [DIR] [HOLD] [1L] and select “Activate”. (I’ve not tried this out to verify it yet.)

HOLDING PATTERN SPEED CONTROL

When in auto, speed will slow from cruise to maximum range speed approaching the
holding pattern and then resume cruise speed leaving the pattern.

To avoid these large speed/power changes, select manual speed control and set
desired holding speed.

Patterns – Holding, radial or orbit patterns should only be entered through the master
FMS when operating in Dual mode. There is no restriction when operating in Initiated
Transfer, Single or Independant modes.
(AFM 1-30 25 JUL 95)

GPS BASED AREA NAVIGATION

Was certified on or about April 1991

Requires a constellation of 21 satellites to assure 24 hour coverage worldwide.

24 satellites with 3 held in reserve.

300 foot accuracy (eventually 0.1 meter with differential ground station reported).

WEIGHTING PRIORITY -- FMZ-800 SERIES

Over land:

GPS position -- 50%

Gulfstream IV Notes 18
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VOR or DME position -- 50% (when received)

17 miles offshore: DME/VOR input ignored, IRS's equally weighted against GPS
receivers.

Example: 1 GPS receiver/3 IRS's -- each given 25% weighting

2 GPS receivers/3 IRS's each weighted 20%

The FMS's factor in IRS drift preceding loss of VHF nav sources

WEIGHTING PRIORITY -- FMZ -2000 SERIES

100% GPS weighting is used for navigation, with DME/DME or VOR/DME used for
logic testing, if a valid signal is received. Outside of VOR/DME coverage, IRS sensors
are used to for reasonableness testing.

FMS navigation based solely on Global Positioning System (GPS) sensor data is not
permitted unless the navigation computer software is NZ 4.1 or later.
(AFM 1-24, 6 DEC 96)

THIRD IRS POSITION SENSOR

With the installation of two GPS position sensors, the third IRS sensor is not required for
NATS/NMPS redundancy.

GPS position sensors provide qualified backup for MNPS airspace at a lower cost.

NMPS requires only two position sensors capable of providing position data to two
navigation computers (FMS or LaserTrak computers).

One may be a GPS.

AHRS to third IRS upgrade costs about $170,000 and is not cost effective.

GPS APPROVED USES

The following information is extracted from the Summer 1997 Honeywell FMS
Technical Newsletter:

The introduction of GPS to the aviation community has generated a revolutionary improvement in
navigation capability and accuracy. It has also generated a high level of confusion regarding its
approved uses. This article provides an overview of GPS operational approvals. In particular, it
discusses the use of GPS for approach procedures and in oceanic/remote airspace.

The Categories
Gulfstream IV Notes 19
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When describing the certification of navigation sensors, the approval is granted for one of three
categories: Supplemental, Primary, or Sole. Until recently, GPS use has been approved using
these same categories. Category definitions differ from state to state as well as the agencies
within each state. This has contributed to the confusion. As a result, certification agencies are
beginning to move away from the use of these categories. Instead, they specifically refer to what
GPS can and cannot be used for. With this in mind, the remainder of this article will refer to the
specific uses of GPS. However, the following category definitions (based on JAA guidance
material) are provided to help you understand the terminology.

Supplemental - A navigation system that must be used in conjunction with a sole-means

navigation system. Approval for supplemental-means for a given flight phase requires that a sole-
means navigation system for that phase of flight must be on-board and operational.

A supplemental-means navigation system must meet the same accuracy and integrity
requirements as a sole-means navigation system. There is no requirement to meet availability
and continuity requirements. Operationally, while accuracy and integrity requirements are being
met, a supplemental-means system can be used without any cross-check with the sole-means
system.

Primary - A navigation system approved for a given operation or phase of flight that must meet
accuracy and integrity requirements. A primary-means navigation system need not meet full
availability and continuity of service requirements. Safety is achieved by limiting flights to specific
time periods and through appropriate procedural restrictions.

There is no requirement to have a sole-means navigation system on-board to support a primary

means system.

Sole - A navigation system which, for a given phase of flight, meets the following four navigation
system performance requirements: accuracy, integrity, availability, and continuity of service.

Any sole-means navigation system could include one or more sensors, possibly of different types.

Currently GPS is capable of supporting a variety of operations. However, it will require some form
of augmentation before it can provide an equivalent level of service as the existing ground
navaids.

Enroute and Terminal Operation

For TSO C115b/C129 GPS equipment, you must have other (non-GPS) operable equipment
appropriate to the route to be flown. For domestic operation, the back-up source is generally
VOR/DME. For oceanic/remote operation, the back-up source is generally IRS (after September,
when Omega is scheduled to be shut down, VLF/Omega will no longer be acceptable).
Oceanic/remote operation will be discussed in more detail later in this article. Note that this back-
up navigation does not need to be integrated into the FMS. The pilot simply has to have a means
of navigating if GPS is no longer available.

Non-Precision Approach Operation

The certification of an FMS/GPS to TSO C129 class A1, B1, or C1 approves the system for use in
approach. The operational approval and procedures for flying these approaches vary by state.

The use of GPS for non-precision approach can be considered in three categories: Non-GPS
approaches, GPS-overlay approaches, and GPS-only approaches.
Gulfstream IV Notes 20
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Non-GPS Approaches - In all countries where GPS is allowed as a supplemental navigation

system, the FMS with GPS may be used for guidance on non-precision approaches. That is,
provided that the navaid on which the approach is based (VOR, DME, NDB, etc.) is tuned,
displayed, and monitored. If there is any discrepancy between the GPS (FMS) and the
procedure-specified navaid, the navaid must be used.

GPS Overlay Approaches - An approach is considered as an ‘overlay’ approach when GPS is

approved for executing an existing non-precision instrument approach procedure developed for
ground navaids. The procedures eligible for GPS overlay are generally limited to VOR,
VOR/DME, VOR/TAC, NDB, NDB/DME, and RNAV. Localizer-based approaches are not eligible
for GPS overlays. The approach procedure MUST be authorized by the country for the use of
GPS. This means ‘or GPS’ must be included in the title. When this is the case, the approach may
be executed using the GPS (FMS) without the need to tune, display, or monitor the procedure
specified navaid. However, the navaid and the associated airborne avionics to use this navaid
must be operational. Keep in mind that whenever there is an underlying navaid available, it is a
good practice to display and monitor this navaid on the cross-side.

GPS-Only (Stand-Alone) Approaches - GPS-only approach applies to those approaches

defined solely for the use of GPS navigation. As the name indicates, the approach may be
executed using GPS without the need to tune, display, monitor, or even have operational, another
navigation source. However, a non-GPS-based approach procedure must be available at the
destination or alternate (including take-off and/or enroute alternates, when applicable). The
missed approach procedure must not be based on the use of GPS. In addition, when planning to
use a GPS-only procedure, the required GPS integrity (RAIM or equivalent) must be confirmed
during the pre-flight planning for the destination ETA.

Oceanic/Remote (O/R) Operation

For TSO C115b/C129 systems, GPS may be used together with a sole means system (e.g., IRS)
in O/R airspace. This includes the use of GPS as ONE of the two long-range navigation systems
on routes where two long-range navigation systems are required. For O/R routes which require
only one long-range navigation system, GPS can be used as the ONLY long-range navigation
system. This policy applies to all O/R airspace, including MNPS (although specific MNPS
operational qualification must still be granted). Note that the JAA is currently reviewing their
guidance on this item and are likely to require 8110.60 approval, as described below, to use GPS
in these applications.

In the absence of IRS or VLF/Omega, GPS may be used as the only long-range navigation
system provided operational approval has been granted. This approval is based on the system
and its operation meeting the requirements of FAA notice 8110.60. This document provides
several requirements for the airborne GPS/FMS system as well as a requirement for pre-dispatch
assessment of the availability and continuity of function of the GPS.

The requirements of 8110.60 can be divided into the following four categories:

Exclusion of failed satellites - The GPS receiver must be able to detect failed satellites and
remove them from the position computation. This exclusion must be automatic (no pilot action
required).

Crew annunciations - GPS position uncertainty (RAIM) must be displayed to the crew upon
request. Loss of GPS navigation must be appropriately indicated to the crew.

Improbable loss of navigation - In most cases, this means dual navigation systems are required.

Pre-departure verification of Fault Detection and Exclusion (FDE) - A method of checking the
satellite constellation along the intended route of flight must be available. This computation can
Gulfstream IV Notes 21
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be performed within the on-board equipment, in a PC, or other off-line computer. However, it
must use the same RAIM/FDE calculation as the on-board GPS receiver. Prior to any GPS
primary-means remote/oceanic operation, the continuous availability of GPS navigation and
acceptable availability of FDE must be determined.

The Honeywell FMZ-2000 / GNSSU system has been approved by the FAA as meeting the
requirements of 8110.60. A letter of design approval from the FAA is available for use in
facilitating installation and obtaining operational approval for primary-means use of GPS in
remote/oceanic airspace.

GPS Augmentation

To remove the requirements for integrity predictions (i.e., RAIM and FDE), the availability and
continuity of service requirements must be met for the selected phases of flight without
restrictions. To achieve this, the current system (constellation) will require support from either a
wide area augmentation system (e.g., WAAS in the US, EGNOS in Europe, MSAS in Japan), the
Russian GLONASS system, or some other augmentation source (e.g., IRS-blending). One or
more of these systems are likely to be available soon after the year 2000.
(Honeywell FMS Technical Newsletter – Summer 1997)

Required Navigation Performance (RNP)

We have received many questions from operators regarding Required Navigation Performance
(RNP) being implemented in Europe and the Central and Northern Pacific. This edition of the
FMS Technical Newsletter will explain the RNP concept and how it relates to the topic of
Communication Navigation Surveillance / Air Traffic Management (CNS/ATM).

What is CNS/ATM

Over the next twenty years, the number of aircraft operating worldwide is expected to double.
Recent studies regarding this increase in air traffic indicate that within ten years, the present air
traffic control system will be overwhelmed. Such an increase will result in significant delays and
unacceptably degraded levels of safety.

At the same time, several new technologies have been developed for aircraft application. These
are primarily related to space-based methods for communication and navigation. Under the
sponsorship of the International Civil Aviation Organization (ICAO), the aviation community has
been considering and developing methods of applying this emerging new technology to update
the existing air traffic control system. The initial concept resulting from this effort was the Future
Air Navigation System (FANS) and operational applications for FANS 1 and FANS A primarily in
the South Pacific. Since that time, ICAO and many industry groups have continued to refine the
FANS concept. This activity is described as Communication Navigation Surveillance / Air Traffic
Management (CNS/ATM).

The benefits provided by the CNS/ATM concept will be increased system capacity, additional and
efficient user-preferred routing as well as enhanced safety.

RNP

With the introduction of Global Position System (GPS), aircraft navigation has changed
dramatically. It is now possible for aircraft to maintain a highly accurate position. This not only
applies to approaches, but also applies to all phases of flight including oceanic and remote
operation.
Gulfstream IV Notes 22
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RNP dictates the aircraft navigation accuracy requirements for operation in certain airspace or
procedures. For example, RNP-5 means that the aircraft must have navigation equipment with
enough accuracy to keep the aircraft within 5 NM cross-track and 5 NM along-track from the
desired flight path. Similarly, RNP-10 requires an accuracy of 10 NM cross-track and 10 NM
along-track from the desired flight path.

If all aircraft operate with equipment that meets or exceeds the RNP value for the designated
airspace, it is possible to reduce the separation between aircraft. For example, current track
separation over the Pacific is 100 NM. With the implementation of RNP-10, this will be reduced to
50 NM. Even lower values will be implemented in the future.

The first widespread applications of RNP (outside of the FANS 1/A routes) are in Europe and the
Central and North Pacific. The following two sections of this article provide additional information
on these implementations and what it means to operators.

Basic Area Navigation (BRNAV) in Europe

On April 23, 1998, aircraft operating IFR in European airspace are required to meet RNP-5. This
is also referred to as Basic Area Navigation (BRNAV). As previously stated, RNP-5 requires an
aircraft to be equipped with area navigation (RNAV) equipment capable of 5 NM along-track and
cross-track accuracy. BRNAV airspace exists over land where VOR/DME navaids are available.
RNAV equipment capable of VOR/DME or DME/DME updating meet BRNAV accuracy
requirements.

The European JAA has published advisory material (AMJ 20X2) concerning the approval of
navigation systems for BRNAV operations. This material states that navigation equipment
installed in accordance with the advisory material contained in U.S. FAA AC 90-45A, AC 20-130,
AC 20-130A, AC 20-138, or AC 25-15, is acceptable for BRNAV operations. If the Aircraft Flight
Manual (AFM) lists one of the above AC’s, or states that the aircraft is RNP-5 capable, no further
compliance documentation is required.

At the time of this article, the FAA AC for operational approval of navigation equipment for
BRNAV airspace (AC 90-BRNAV) was still in draft format. The draft version was similar to the
JAA material. If the AFM states that the navigation equipment installed on the aircraft is in
accordance with one of the above AC’s, or states that the aircraft is RNP-5 capable, no further
compliance documentation is required. If the AFM does not contain such a statement, then it is
necessary for the operator to provide proof that the navigation system meets BRNAV
requirements. In addition, a Letter Of Authorization (LOA) must be received.

All Honeywell BCAS FMS software versions and hardware platforms (NZ-6xx/8xx/9xx, NZ-2000,
and IC-800) meet BRNAV requirements when interfaced to the onboard VOR/DME sensors. In
addition, only a single FMS need be operational when operating in BRNAV airspace. The FMS
engineering department has created a document stating that the Honeywell BCAS FMS meet
BRNAV requirements. Contact the FMS Product Support group for additional information about
this document.

RNP-10 in Pacific

Beginning April 23, 1998, aircraft operating in the Northern and Central Pacific are required to be
RNP-10 compliant. This requires aircraft to be equipped with a navigation system capable of 10
NM cross-track and along-track accuracy. In the future, RNP-10 will be extended to other areas of
the Pacific.

Similar to MNPS over the North Atlantic, all operators of FAA registered aircraft are required to
receive a Letter Of Authorization (LOA) for RNP-10 operations. FAA Order 8400.12A provides the
Gulfstream IV Notes 23
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guidelines required for operators to receive RNP-10 operational approval. This document became
effective on 2/9/98.

Since the aircraft is over water, it is necessary to have dual FMS. In addition, the FMS must
interface to a minimum of two sensors. The sensors may be comprised of either two IRSs or two
GPSs or one of each. VLF/Omega is not an acceptable sensor for RNP-10 operations.

Due to the drift characteristics of IRS sensors, its ability to meet RNP-10 requirements is limited
in time. FAA Order 8400.12A allows a maximum of 6.2 hours flight time which commences upon
the IRS being placed in the navigation mode. Should the FMS enter DME/DME updating once it
is airborne, the maximum flight time becomes 5.9 hours after the FMS stops DME/DME updating
or 5.7 hours for VOR/DME updating. For example, assume an aircraft departs and navigates for
3.0 hours on the IRSs before the FMS enters DME/DME updating. Should the FMS cease
DME/DME updating and resume IRS navigation, the aircraft may fly another 5.9 hours in RNP-10
airspace using the IRS for navigation. Similarly, if the FMS enters VOR/DME updating once
airborne, the maximum flight time becomes 5.7 hours after the FMS stops VOR/DME updating.

Aircraft equipped with dual GPS and no IRS may qualify for RNP-10 operations if the aircraft has
been approved to use GPS as a primary means of navigation for oceanic and remote operations
(i.e., compliant with FAA Notice 8110.60). There is no time limit for these aircraft in RNP-10
airspace. It is necessary to run an approved dispatch FDE availability prediction program prior to
dispatch.

Aircraft equipped with dual FMS, at least a single IRS, and a single GPS qualify for unlimited time
operations in RNP-10 airspace. The GPS must have RAIM capability and the FMS must be a
multi-sensor system that uses the GPS based upon its RAIM values.

All NZ-6x0/8x0/9x0 were certified using RNAV certification requirements that did not include GPS.
The GPS position was compared to a certified sensor (VOR/DME, DME/DME, VLF, IRS) and was
blended into the FMS position if the comparison passed. If the comparison did not pass, the GPS
was not used for navigation. GPS RAIM was not used to determine if the GPS could be utilized
for navigation. Therefore, these systems meet RNP-10 requirements; however, they are
operationally bound by the IRS limitations. These aircraft configurations gain no additional time in
RNP-10 airspace if GPS sensors are installed in the aircraft.

All NZ-2000 are certified using the most recent GPS certification requirements. The aircraft RNP-
10 operational limitations are based upon the sensors installed on the aircraft. If only IRS sensors
are installed, operations are based on the IRS limitations. If dual GPS sensors (HG2021GD02)
are installed with no IRS, operations are based on the limitations for using GPS as a primary
means of navigation for oceanic and remote operations. If at least a single IRS and single GPS
are installed, the aircraft qualifies for unlimited time in RNP-10 airspace.

IC-800 with software versions prior to NZ4.3 are similar to NZ-6x0/8x0/9x0 in RNP-10 operational
capability. IC-800 with software versions NZ4.3 or later meet the newer GPS certification
requirements and are similar to NZ-2000 in operational capability.

Needless to say, the RNP-10 operational approval is more complex than the BRNAV/RNP-5. We
have been working with aircraft manufactures and completion centers to revise Aircraft Flight
Manuals (AFM) for aircraft with Honeywell FMS to state if the aircraft meets RNP-10
requirements. This makes it much easier for the operator to show compliance to the FSDO to
receive a LOA. If the AFM does not contain such a statement, it is necessary for the operator to
provide proof that the navigation system meets RNP-10 requirements.

We have created a document stating which Honeywell BCAS FMS meet RNP-10 requirements
and any applicable limitations. Contact the FMS Product Support group for additional information.
Gulfstream IV Notes 24
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(Honeywell FMS Technical Newsletter – March 1998)

RAIM

Receiver Autonomous Integrity Monitor

A good RAIM check is required for any navigation based solely upon the GPS position
sensors.

This especially applies to GPS only approaches where the approach is not based on
ground navaids.

RAIM is not required for GPS overlay approaches where the underlying approach navaid
is being received normally or any FMS based approach on a non-localizer, non-precision
approach procedure.
(GIV AFM Supplement GIV-95-04 dated 3 Nov. 95)

RAIM Computations

There are four basic types of RAIM: current RAIM, pilot-select RAIM, destination RAIM, and 5-
minute "look-ahead" RAIM. The latter three are all applications of predictive RAIM.

Current RAIM is the actual RAIM from the GPS sensor, as displayed on the GPS STATUS page.
This value represents the integrity of the GPS position based on the current satellite geometry.
Pilot-selected RAIM shows predictive RAIM for ± 15 minutes at 5-minute intervals for any
specified location and zulu time. Destination RAIM provides predictive RAIM for ± 15 minutes at
5-minute intervals for the destination identifier at the destination ETA. The 5-minute "look-
ahead" RAIM is a predictive RAIM function that the FMS uses in preparation for a GPS
approach. It is evaluated when the aircraft is two miles before the final approach fix (FAF). It
results in a crew alert if RAIM will exceed the limit during the next 5 minutes (the time allowed to
complete the approach).
(Honeywell FMS Technical Newsletter – Summer 1997)

FMS/GPS BASED APPROACHES

APPROACH AUTHORIZATIONS

The authorization for using the FMS for non-localizer, non-precision approaches is found
in the AFM in the limitations chapter page 1-24. When using this authorization, the
underlying approach navaid must be in service and used in the cockpit.

The authorization for using the the FMS for GPS overlay or GPS only approaches (ex:
VOR 24 or GPS, GPS 18) is found in the GIV AFM Supplement No. GIV-95-04 for the
Honeywell FMZ-2000 Flight Management Systems software version 4.1 or later. This
authorization allows the approach to be conducted even when the underlying approach
Gulfstream IV Notes 25
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navaid is not in service. Currently, this authorization only applies to approaches in U.S.
airspace.

In both of the above authorizations, specific conditions must be observed and complied
with.

APPROACH LIMITATIONS

The FMS is approved for vertical and lateral coupled IFR RNAV, VOR, VOR/DME,
ADF, GPS and TACAN approaches under the following conditions:

 The "FMS APPROACH" annunciator is illuminated.

 A published RNAV, VOR/DME, ADF, GPS OR TACAN approach procedure is
used.
 One pilot monitors raw data of referenced NAVAID for VOR, VOR/DME, ADF,
GPS or TACAN approach without NZ 4.1 or later approve version installed.
 FMS navigation mode is GPS, GPS/DME/DME, DME/DME or VOR/DME.
 "DR" or "DGRAD" annunciators are not illuminated.
 Minimum altitude for autopilot coupled IFR VNAV operations is 300 ft. AGL or
50 ft. below MDA whichever is higher.

Note: Additional information regarding FMS approach procedures can be found in GIV
AFM Supplement 95-04 for airplanes with NZ 4.1 or later approved version installed.
(AFM 1-24, 5 JAN 96)

GPS approach capability requires the NZ-2000 system with software version NZ4.1 or
later.

Requirements include:

 12 Channel GPS receiver

 FMZ-2000 System with NZ4.1 software

On production A/C SN 1253 & subs

GPS capable approach flight plan suffix: /G operations permitted when instrument
approaches can be automatically selected from the navigation computer database.
(AFM 1-17, 5 JAN 96)
DEGRADE MODE (DEGRAD)

The amber DEGRAD light comes on when the navaids available do not allow the FMS to
maintain the required navigational accuracy for the current phase of flight.

Phases of Flight:

1. Oceanic
Gulfstream IV Notes 26
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2. Enroute
3. Departure and Terminal
4. GPS Non Overlay Approaches

Sensor Requirements To Illuminate the DEGRAD Light For Each Phase of Flight:

The amber DEGRAD light will illuminate in each phase of flight if the following
conditions are met. Note that the existance on any one of the listed sensors within limits
is sufficient for adequate positional accuracy. All sensors must be out of the stated limits
for the DEGRAD light to illuminate. Using the Oceanic phase of flight as an example,
having a valid IRS sensor input is sufficient to maintain navigational accuracy for that
phase of flight hence the DEGRAD light will not illuminate.

Oceanic

1. GPS invalid or RAIM values exceeding limits

-AND-
2. DME/DME invalid
-AND-
3. VOR/DME invalid or navaid greater than 200 NM away
-AND-
4. IRS invalid

Enroute

1. GPS invalid or RAIM values exceeding limits

-AND-
2. DME/DME invalid
-AND-
3. VOR/DME invalid or navaid greater than 65 NM away
-AND-
4. IRS estimated position error is greater than 2.8 NM (as determined by the FMS).

Departure and Terminal

1. GPS invalid or RAIM values exceeding limits

-AND-
2. DME/DME invalid
-AND-
3. VOR/DME invalid or navaid greater than 40 NM away
-AND-
4. IRS estimated position error greater than 1.7 NM (as determined by the FMS).
Gulfstream IV Notes 27
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GPS Non Overlay Approaches

1. GPS invalid or RAIM values outside of the proper limits

-AND-
2. DME/DME position invalid
-AND-
3. VOR/DME not tuned to proper navaid or position invalid.

If the DEGRAD light illuminates in the Terminal or Approach phases of flight, that does
not mean that adequate sensor accuracy might not exist for the less restrictive Enroute or
Oceanic phases of flight, although this is not automatically the case. The pilots must
determine the reason for the DEGRAD light.
(GIV AFM Supplement GIV-95-04 dated 3 Nov. 95)

VNAV Operations for Non-Precision Approaches

With the introduction of NZ4.1 software, the FMS is certified to fly non-precision approaches.
These approaches consist of all non-localizer based approaches (VOR, VORDME, RNAV, NDB,
GPS). These approaches are stored within the FMS navigation data base, retrieved by the pilot,
and inserted into the active flight plan. The FMS can then be coupled laterally and vertically to fly
the approach. Non-precision straight-in approaches can be divided into two types. The first type
of approach is the straight-in approach where the Missed Approach Point (MAP) is located at or
prior to the runway threshold. The second type of approach is where the MAP is located past the
threshold. This article will discuss the VNAV operational aspects of both approach types as well
as provide examples.

ARINC 424

Prior to discussing VNAV operations, it is helpful to provide some background information

regarding how approaches are stored in the navigation data base.

Aeronautical Radio, Inc. (abbreviated ARINC and pronounced air-ink) 424 is the industry
standard for navigation data bases for airborne navigators. The primary purpose of ARINC 424 is
to define a standard for the distribution of navigation data. If a supplier provides data in ARINC
424, then the buyer will know the format of the data received from the supplier. As an example,
Honeywell receives its navigation data base content from Jeppesen in ARINC 424 format.

ARINC 424 also provides rules for the coding of procedures. The rules are defined by the ARINC
424 committee and are designed to provide standardization of navigation data. An example of
this is the vertical path coding of non-precision straight-in approaches. If the Missed Approach
Point (MAP) is the runway, ARINC 424 requires the vertical path coding of the approach to
consist of a single path to the runway from the Final Approach Fix (FAF). The vertical path is
steep enough to clear all step down altitude constraints for the final approach segment. In
addition, the vertical path guidance is to 50 feet above the runway threshold. If step down fixes
exist between the FAF and MAP, the approach procedure stored in the navigation data base will
not contain the step down fixes. VNAV was designed for these types of approaches. Rather than
having to fly step downs, it is possible to fly a constant vertical path from the FAF to the runway.
This single path emulates an ILS glideslope. If the MAP is past the runway threshold, ARINC 424
requires that the Minimum Descent Altitude (MDA) be coded at the MAP. These types of
approaches are not designed for VNAV path operations. If VNAV path guidance is used, the
aircraft will arrive at the MAP at the MDA, and thus not be in a position for landing. Vertical Speed
(V/S) should be used as the descent mode for these types of approaches.
Gulfstream IV Notes 28
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The following paragraphs review two approaches. The CDU artwork is based upon NZ4.1
software functionality and apply to aircraft without a performance computer (non GIV aircraft).

MAP LOCATED AT OR PRIOR TO RUNWAY THRESHOLD

As an example of an approach where the runway is the MAP, we will review the Garden City, KS
VOR DME Rwy 17 approach, shown in Figure 1. For this example, we will create a flight plan
direct from KPHX to the start of the DME arc. We will use the 270° radial from GCK as the Initial
Approach Fix (IAF). Figures 2 and 3 show the FMS CDU pages following initialization of the FMS
and selection of the approach.

The IAF is shown as waypoint D270I. This waypoint name follows the ARINC 424 naming
convention for DME arc waypoints. The D indicates the waypoint is defined by DME, the 270 is
the radial, and I represents the arc radius based upon its position in the alphabet (I is the ninth
letter of the alphabet; the arc radius is 9 NM). The inverse video A adjacent to D270I indicates the
start of the arc. D270I shows a predicted crossing altitude of 8900 feet using a default 3.0°
descent path. The FMS displays altitude and angle constraints in large font while a predicted
altitude or default angle is shown in small font. It should also be noted that Jeppesen is starting to
list ARINC 424 waypoint names on approach plates to provide consistency between the approach
plate and the navigation data base in the FMS.

The next waypoint in the flight plan is CF17. The inverse video A adjacent to the waypoint,
indicates the termination of the DME arc. Note that the approach plate does not show a waypoint
CF17. The unnamed waypoint, located at 9.0 DME at the end of the arc, represents waypoint
CF17 on the approach plate. The FMS CDU shows an altitude constraint of 4500A (4500 feet AT
OR ABOVE). Should VNAV path guidance be used for this portion of the approach, the FMS will
treat the waypoint as an AT constraint and cross CF17 at 4500 feet using a 3.0° path.

Note: NZ5.0 and later software will not treat the way-point as an AT constraint. These software
versions will look at the waypoints further in the flight plan. If an altitude constraint exists further in
the flight plan, the FMS will attempt to compute a single path from that waypoint backwards such
that all AT OR ABOVE and AT OR BELOW constraints in the flight plan are satisfied. This
functionality currently exists on GIV aircraft and is available in NZ5.0 for all aircraft. From CF17,
the next waypoint is FF17 which is the Final Approach Fix (FAF). This waypoint shows an altitude
constraint of 3600 feet on the CDU. This is shown in the profile view of the approach plate. The
angle 1.7° displayed adjacent to the 3600 indicates the FMS will use a 1.7° path to descend from
4500 feet to 3600 feet. Thus the FMS would fly a 3.0° path to CF17 and then transition to a
shallower path of 1.7° to FF17. Note: As discussed in the previous paragraph, this is an example
where NZ5.0 will fly a single path that meets multiple constraints in the flight plan. NZ5.0 will fly a
constant 3.0° path from cruise altitude to FF17. This single path will satisfy the 4500 foot AT OR
ABOVE constraint at CF17. This eliminates the transition from a 3.0° to 1.7° path outside the
FAF.

From the FAF, the next and last waypoint of the flight plan is the MAP, RW17. The FMS is
showing a 3.0° descent path to an altitude of 2940 feet at the MAP. Both the angle and altitude
are shown in large font indicating they are constraints that were retrieved from the navigation data
base. The altitude 2940 represents the Touch Down Zone Elevation (TDZE) plus 50 feet (2886 +
50 = 2936 rounded to the nearest 10 foot increment = 2940). If VNAV path guidance is used for
this approach, the FMS would provide a 3.0° descent path from the FAF to 50 feet above the
runway threshold. This is similar to a glideslope on an ILS. It is important to note that the angle
constraint for this approach is retrieved with the approach procedure from the navigation data
base. This angle will clear all obstacles and meet all step down altitude constraints on the final
approach segment.
Gulfstream IV Notes 29
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It is important that the vertical angle constraint associated with the runway is not changed
to a lesser value because obstacle clearance will not be guaranteed. Also vertical DIRECT-
TO to the runway waypoint is not recommended since the FMS may compute a smaller
vertical angle than the required vertical angle for the procedure.

For approaches where the MAP is located prior to the runway, the approach will be coded similar
to the above example. The difference will be that the MAP will contain a computed altitude
constraint that is equal to the glidepath altitude for a path projected from the runway threshold
back to the FAF. The ACTIVE FLT PLAN will show the MAP with an angle and altitude constraint.
The runway is then added after the MAP in the active flight plan. An example of this type of
approach is the NDB Rwy 30 at Long Beach, CA (KLGB). Figure 4 illustrates how the altitude
constraint at the MAP is computed for the NDB Rwy 30 approach. Even though the approach
terminates at the MAP, the altitude constraint at the MAP is based upon a glidepath projected to
the runway threshold.

MAP located past the RUNWAY threshold

We will now review an example where the MAP is located past the runway threshold. For this
example, the VOR or GPS Rwy 28 approach for Albany, NY, shown in Figure 5, will be used. The
flight plan consists of a direct flight from KPHX to the approach transition waypoint ALB. The CDU
pages for this approach are shown in Figures 6, 7, and 8. The first waypoint is the approach
transition waypoint

ALB. The FMS shows an altitude constraint of 3800 feet AT OR ABOVE with a default descent
angle of 3.0°. The altitude constraint is shown in large font indicating that it was retrieved with the
procedure from the navigation data base. The angle is the FMS default angle for descent. Note
that the FMS will treat this waypoint as an AT constraint even though it is an AT OR ABOVE
constraint. Note: See the preceding example regarding NZ5.0 treatment of AT OR ABOVE
constraints.

From ALB, the FMS will fly outbound to LANGY for the procedure turn. LANGY is shown with an
altitude constraint of 3800A (AT OR ABOVE 3800 feet) and a predicted speed of 250 KTS. The
inverse video P adjacent to the waypoint indicates a procedure turn will be performed at LANGY.
The 250 KTS is shown in small font indicating that the airspeed is based upon the speed
schedules defined in PERFORMANCE INIT. The pilot may enter a constraint if a particular
airspeed is desired at the waypoint.

The next waypoint in the flight plan is *INT01. This waypoint represents the location where the
aircraft will intercept the final approach course inbound for Rwy 28. The asterisk (*) denotes that
the waypoint is temporary, while the number (01) indicates that it is the first temporary waypoint
that the FMS has computed. In addition, the number is odd indicating it was computed by the left
FMS (even numbers are assigned by the right FMS). This waypoint has an altitude constraint of
3800A with a predicted speed of 250 KTS. The FMS will fly over *INT01 at 3800 feet.

From *INT01, the next waypoint is the Final Approach Fix (FAF) LANGY. This waypoint has an
altitude constraint of 2400A and a descent angle of 2.1°. The FMS will cross LANGY at 2400 feet
using a 2.1° path.

From LANGY, the next waypoint is the MAP (ALB) which is located past the runway. ALB has an
altitude constraint of 780 feet, which is 495 feet above the TDZE of 285 feet. The 780 foot
constraint is equal to the straight-in landing MDA for runway 28. If VNAV path guidance was used
for this approach, the aircraft would arrive at ALB 495 feet above the runway. It would not be in a
position for a straight-in landing on runway 28. The inverse video F adjacent to the bearing
between LANGY and ALB indicates that ALB is a fly-over waypoint. The last waypoint in the flight
plan is RW28. The FMS adds the runway for the approach after the MAP. Notice that the FMS
Gulfstream IV Notes 30
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provides heading and distance direct from the MAP to the runway. No altitude or angle constraint
is associated with the runway under these conditions. It is marked as a fly-over waypoint.

Summary

It is important that the flight crew understand the capabilities and limitations of using VNAV path
guidance for approach operations. Flying a vertical path from the FAF to the MAP will provide a
smoother ride and result in the non-precision approach looking like an ILS approach. But VNAV
path guidance for approaches where the MAP is located past the runway threshold will place the
aircraft in a position where a straight-in landing is not possible.

During approach briefings, you may want to add statements regarding the vertical portion of the
non-precision approach procedure. If the MAP is located prior to or at the runway threshold,
VNAV path guidance may be used for the descent to the runway. In the briefing, the Pilot Flying
(PF) may want to indicate what vertical mode, VPATH or V/S, will be used during the approach. If
VPATH is used for the descent, VNAV path guidance should be cross checked against any step
down fixes to ensure that altitude requirements are being satisfied. If the approach is a GPS
overlay approach, it is recommended to display and monitor the underlying navaid.

For approaches where the MAP is located past the runway threshold, we do not recommend
using VNAV during the descent. If VNAV path guidance is used, the aircraft will arrive at the MAP
at the MDA, and thus not be in a position for landing.

Some operators like to add the Visual Descent Point (VDP) to the flight plan and place an altitude
constraint at the VDP. This will allow the use of VNAV path guidance for the approach. While this
is permitted, we do not recommend this procedure. We recommend using Vertical/Speed (V/S)
for descent and fly the approach without VNAV. This reduces the chances for VDP entry error
and eliminates confusion between crew members if both are not familiar with the practice of how
to program the VDP.

In a future issue of the FMS Technical Newsletter, we will discuss changes being made to ARINC
424. These changes are called Supplement 14 within the industry and will effect the vertical and
lateral coding of non-precision approaches. The changes are designed to code non-precision
approaches such that VNAV path guidance can be used when the MAP is not located at the
runway threshold. We will keep you informed of these changes and how they will affect approach
operations.
(Honeywell FMS Technical Newsletter – September 1998)

Missed Approach Prompt

We have recently been receiving questions from operators regarding the use of the MISSED
APRCH prompt. This prompt is displayed at 4L on the ACTIVE FLT PLAN page when the aircraft
is 2 NM from the Final Approach Fix (FAF). The purpose of this prompt is to allow the ability to
activate the missed approach procedure. When activated, the missed approach procedure is
inserted into the active flight plan following the Missed Approach Point (MAP). On most aircraft,
the FMS performs this same action when the Takeoff and Go-Around (TOGA) switch is activated
on the throttles.

The prompt was added to the CDU to support installations where the FMS is not able to interface
with the TOGA switch. The flight crew would activate the missed approach procedure via the
CDU when the miss commences. The prompt also allows a flight crew to activate the procedure
without activating the GA Flight Director Mode. An example would be aircraft equipped with
autothrottles and it is desired to not use the GA power setting (such as a decision to miss when
the aircraft is at or near the FAF).
Gulfstream IV Notes 31
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Selection of the prompt also transfers the FMS back to the terminal mode of operation. When this
occurs, the APRCH annunciator extinguishes and the EFIS switches HSI sensitivity to terminal (if
supported by EFIS).

Some operators are selecting the MISSED APRCH prompt when the aircraft is at the FAF for
localizer based approaches. These operators want to see the missed approach procedure
displayed on the EFIS prior to commencing the final approach segment. This allows the flight
crew to graphically see the procedure. Since the FMS is not coupled during localizer based
approaches, the FMS will remain in terminal mode during the final approach segment without any
operational consequences.

This is not the case if the prompt is selected during FMS coupled approaches (non-localizer
approaches). Should this occur, the FMS will not illuminate the APRCH annunciator, and the HSI
sensitivity will remain in the terminal mode. Note that all Aircraft Flight Manuals or Flight Manual
Supplements for the FMZ-2000 require the APRCH annunciator to be illuminated during an FMS
approach. We recommend not selecting the MISSED APRCH prompt unless an actual missed
approach procedure is commencing. Our reasons for this are as follows:

1. By not selecting the prompt, all approaches will be selected and flown in the same manner.
Should the flight crew select the MISSED APRCH prompt for localizer based approaches, they
must remember not to select the prompt for FMS approaches. This is a memory item that can be
easily forgotten.

2. Should the prompt be selected by accident during an FMS approach, there is not an easy
method to “undo” the mistake. One must go to the ARRIVAL page, reselect the approach, and
activate it. This is not something one wants to be doing when the aircraft is at the FAF inbound for
landing.

3. Graphically reviewing the missed approach procedure on the EFIS display does not provide
the required resolution for review. A more thorough method would be for the Pilot Not Flying
(PNF) to review the procedure on the CDU as the Pilot Flying (PF) briefs the missed approach
procedure from the approach chart. This allows for the review of actual courses, altitude
constraints, holding pattern entry, and the hold inbound course retrieved from the FMS navigation
database.
(Honeywell FMS Technical Newsletter – September 1998)

VERTICAL NAVIGATION
During vertical navigation, rate of descent is controlled by pitch and speed is controlled
(not very well) by power

POWER LEVER ANGLE

During descent modes where power levers control speed, minimum power lever angle is
limited to 8.

Minimum power lever angle for a FLCH descent is 2.

This may explain tendency towards excess speed in VNAV/vertical rate descents.
Gulfstream IV Notes 32
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VERTICAL DEVIATION (GLIDE SLOPE)

Information displayed if:

 Performance Initialization complete

 FMS is selected on PFD as the nav source
 "LNAV" must be selected
 VNAV armed -or- Vertical Direct selected

Note: Use of Vertical Navigation mode is not recommended when using QFE settings on
the altimeter.

VERTICAL GUIDANCE TECHNIQUE

 Select FMS Nav

 Enter 3/Apt elevation at destination (ie. TEB 3/0009
3 Glideslope/field elevation (some use elevation + 50')
Will give a 3o vertical G/S to runway from TOD

Vertical Direct can only be selected to manual altitude entries (large numbers)

Auto speed change to transition altitude speed will occur 1000-6000' above Transition
Altitude based on rate of descent

Ernie Bott (FSI-SAV) uses M.82/320 descent speeds for smoother VNAV descent

CLIMB SPEED

Normal climb speed will be according to the speed schedule programmed into
Performance Initialization.

If level at cruise altitude and a climb of 6,000' or less is selected, the aircraft will climb at
cruise speed.

VNAV CLIMBS

During a VNAV climb the aircraft will climb at normal FLCH climb rates (max climb
power, pitch controls speed).

Will not attempt to follow a specific path.

VNAV climbs only allow intermediate level-offs to meet programmed climb

restrictions.
Gulfstream IV Notes 33
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VNAV climb indications: "VNAV" & "FLCH" push switches illuminated

After an intermediate level off: Only "VNAV" push switch is illuminated

When cleared for further climb: Push "FLCH" push switch (takes 3 seconds to light,
don't push twice or it will toggle OFF again).

Note: If the aircraft leveled itself off to make a published climb restriction, it will
recommence climb automatically when the climb restriction waypoint is passed again
showing "VNAV" & "FLCH" push switches illuminated.

VNAV DESCENTS

When the VNAV descent is armed, the "VNAV" push switch light will illuminate, but
the "ALT" hold light will remain illuminated

Approaching top of descent (one minute prior) a tone will sound and a "RESET ALT
SEL?" message will appear

At top of descent and with the Altitude Selector reset for a lower altitude, the aircraft will
start down the computed glide path and the "ALT" hold light will go out.

If the VNAV Mode is selected past the top of descent point, both the "VNAV" and
"FLCH" lights will illuminate and the aircraft will start descent in the FLCH mode until it
has descended to the programmed glide path at which time the "FLCH" light will
extinguish and a VNAV descent will begin on the glide path.

"INCREASED DRAG REQUIRED"

Triggers at ten knots over programmed airspeed.

Does not indicate how much increased drag is required.

If speed brakes are deployed and power levers start to come forward (Autothrottles
On), or speed decays -- too much drag!

Options in this situation:

1. Crack speed brakes, slowly increase until PL's start increasing

2. Disconnect autothrottles to eliminate 8 minimum power lever angle

Gulfstream IV Notes 34
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3. Ignore the message -- live with the extra speed

"POWER" ANNUNCIATION AT TOP CENTER OF PFD

The autothrottles cannot add or take off enough power to maintain the programmed
speed.

“POWER” will appear after a ten knot difference occurs for more than 60 seconds.

FMS OPERATING TIPS

INITIALIZATION

If A/C accelerates to 60 KTS and then slows -- Performance Data lost

If Step Increments are set during Performance Initialization:

 Fuel calculations will be computed on the assumption that step climbing will
occur at the optimum time
 May be overly optimistic if ATC doesn't permit climb
 Better to leave at zero until cleared to climb to the next altitude if fuel critical or at
least check fuel figures at 0' step climb before selecting desired increment.

On Takeoff Initialization page 1/4 it is possible to manually enter temp.

If the temperature is manually entered and the sensed temperature is different, V-

speeds might not be calculated.

When using Flex EPR on runways below 8000', at heavier weights, Flex EPR is
programmed to use full runway for liftoff.

No safety margin.

To avoid -- manually enter the runway length to 1000' less than actual in Takeoff
Initialization.

If ramp gross weight is over 73,200 lbs (ie. with max taxi weight of 73,600), V-speeds
will not compute and display.

May force the calculation by subtracting two pax at the ramp

Add them in again before takeoff after fuel burns down

Gulfstream IV Notes 35
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CRUISE SPEED INITIALIZATION -- For a mix of high and low level cruise
operations, set cruise speed to dual speeds of 300/.80

RAPID PERFORMANCE INITIALIZATION: Minimum Required Entries

Page 4/5  Initial cruise altitude

Page 5/5  Pax load

 Cargo
 4R key for Perf Data computation (necessary to force computation)

RAPID TAKEOFF INITIALIZATION: Minimum Required Entries

Page 1/4  A/P wind (may be 0/0)

Page 4/4  4R key for T/O data computation (necessary to force computation)

RAPID LANDING INITIALIZATION: Minimum Required Entries

Page 1/3  A/P winds

 A/P temp

Page 3/3  4R key for Landing Data computation

FLIGHT PLAN ENTRY -- When entering a flight plan, be sure to name it so that it will
be stored in the flight plan database

RESELECTING WAYPOINTS BYPASSED BY A DIRECT-TO PROCEDURE

To reselect bypassed waypoints press the [DIR] and [PREV] keys

Works only on the side selecting the original Direct-To

AUTO PAGING -- To Turn ON or OFF:

 Select Maint Page 2

 Place "FC" (Flight Config) in the 4L position

RUNWAY END OFFSETS

NZ software upgrade NZ 9401 allows direct use of the runway designation for a
reference point in an offset waypoint

"Rwy18/360/10" -- ten miles short of approach end of runway 18.

Gulfstream IV Notes 36
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"Rwy18/180/10" -- ten miles beyond approach end of runway 18.

NZ-9401/NZ4.1 Software

1. Select the Runway line to the scratchpad.

2. Add two diagonals “//“ followed by the desired offset in miles and tenths (e.g.
“RW9//2.4" 2.4 NM short of runway 9).

OUTER (MIDDLE) MARKER COORDINATES (Pre NZ-9401/NZ4.1 software)

For non-domestic airports only -- may be found as follows:

To access OM's in the database use the following:

 If a five letter fix, use fixes name

 If a three or two letter designator, enter the ID followed by "NB" (i.e. "PNJNB" or
"PDNB")
 If still not found, try "OM##" (## = runway number)
Will show all available non-U.S. OM's to the entered runway number by country
-- match lat/longs
A left runway would be: "OM23L", etc.

Middle Marker access works the same way as OM's

See FMS Manual page 5-B-19

DELETE SCRATCH PAD ENTRY: Type "-" and hit "DELETE" Key (NZ-9101 and
subs)

OCEANIC WAYPOINTS ENTRY SHORTCUTS

Type "N52W75" to enter N52-00.0/W075-00.0 (Pre NZ-9401/NZ4.1 software)

Trailing zeros are assumed

Type “5240N” to enter N52-00.0/W040-00.0 (NZ-9401/NZ4.1 software)

-or-
Type "52N40" to enter N52-00.0/W140-00.0

DELETING THE ACTIVE FLIGHT PLAN

To delete the active flight plan, delete the "ORIG" airport

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LINKING STORED FLIGHT PLANS

A stored flight plan can be inserted into the active flight plan

The inserted flight plan can be a route segment such as an arrival or alternate route
portion

The route segment need not originate or terminate at an airport

The inserted flight plans starting point must the same as one of the fixes in the active
flight plan

This technique is very useful for setting up alternate routing to a diversion airport in
advance
Example: A trip from TEB to PBI with a possible last minute destination change to
DAB:

1. Find last common fix to both routes: SBY

2. Enter KTEB-KPBI routing in active flight plan
3. Store routing from SBY to DAB called: "SBY-KDAB" in the custom database
4. If called upon to change destination to DAB, type "SBY-KDAB" in scratch pad
and place on "SBY" in active flight plan
5. The SBY-KDAB routing will be inserted in the active flight plan
6. Delete all waypoints to PBI past SBY
7. Copy "KDAB" from waypoint list on FPL Page to scratch pad and insert it in the
DESTINATION position on right side of screen

POINT ABEAM COORDINATES: Point abeam fixes may be copied to the scratch
pad and then inserted in active flight plans as position/bearing/distance (P/B/D) fixes.

This is useful for tracking trip progress relative to intermediate flight plan fixes when
proceeding direct to a more distant fix.

ADDITIONAL FMS OPERATING NOTES

The following notes were contributed by Jean-Guy Boivin:

Honeywell NZ-2000 FMS G-IV Class Notes

The general flow of operation is:

1- On Ident page: verify that 1 of 2 database cycles is valid for todays’ date
2- Enter a present position (Kxxx, RAMPxx, or Lat/Long)
3- Either create a new flight plan or recall an existing one
4- Fill in the required PERF INIT data
Gulfstream IV Notes 38
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5- Activate the INIT data by pressing the PERF DATA prompt

6- Fly the flight plan from the flight plan pages
7- Use whatever functions & menus are necessary during the flight

PERF INDEX REVIEW

PERFORMANCE INDEX Options:

Page 1/2 PERF DATA DESCENT Page 2/2 T. O. INIT PERF PLAN
T.O. DATA LAND INIT INIT  WHAT-IF  DATA
CLIMB LAND DATA INIT  STORED FPL  DATA
CRUISE SINGLE ENG PERF INIT

The following index review proceeds in the order followed when powering the airplane up,
entering a flight plan and reviewing predictions rather than the order in which the index is laid up.

PERF INIT

The purpose of PERF INIT pages is to furnish the FMS with a comprehensive set of base data to
use in flight planning prediction calculations and more importantly for VNAV calculations.

Pg. 1/5 (no entries allowed on this page)

AIRCRAFT Always G-IV

ENGINE Always “ RR TAY 611”
PZ MODE Should match NZ operating mode selected in Maintenance pages
SW Shows current software version utilized.

Pg. 2/5

On this page we enter our preferred climb, cruise and descent speeds. The descent angle is the
angle used in VNAV descent. Combinations of CAS and Mach numbers are allowed. Cruise can
be MAX SPEED, LRC, MAX ENDURANCE or a hard CAS/Mach entry.

Pg. 3/5

STEP INCREMENT

Steps are used to optimize long-range performance. This entry is the difference between your
current selected cruise altitude and a higher altitude to which you plan to climb to later. So, if the
initial part of the flight will be at FL370 and FL450 will be flown later then, enter 8 or 8000 as the
step increment.

FUEL RESERVE
Gulfstream IV Notes 39
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Entering *DELETE* return this value to the NBAA default. If other fuel reserve calc methods are
desired, press “OR” to enter a reserve either in MINUTES or in LBS.

TO / LDG

This is a fuel allowance (for start, taxi, take-off and ground operation after landing) which is added
to the “fuel required” calculations.

Pg. 4/5

TRANS ALTITUDE 18,000 ft for North America. Alt > trans alt are displayed as Flxxx. Alt <
trans. alt are displayed in thousands of feet

SPD / ALT LIM Optional entry. Use 250 / 10000 for US operations.

INIT CRZ ALT OPTIMUM is the default. Enter your initial cruise alt. here either in Feet
or Flxxx. This entry is critical to initial flight planning predictions.
Changing the altitude with the altitude selector will change / update this
entry.

CRZ WINDS An average wind to cruise altitude should be entered otherwise the FMS
assumes 0 wind for predictions while on the ground. (Fuel & times may
look very unreasonable)

WIND MODEL: Position Blending Ratio

present pos 100% sensed

350 nm ahead (~45 min) 50% sensed / 50% entered
700 nm (~1 ½ hr) 20% sensed / 80% entered

If 0 wind is entered on PERF INIT pg. 4/5, the FMS assumes no wind and STD ISA for the whole
flight for predictions purposes while on the ground. (Fuel, ETE will look very unreasonable).
Sensed winds will blend in when airborne.

If an average wind/temp entry is made on PERF INIT pg. 4/5, it will apply to all waypoints.

If wind / temp entries are made on the PERF PLAN pg. (“W/T” prompts) the entry is applied to
every waypoint forward until a different entry is found. Because the WIND TEMP figure becomes
a blended value, an entry just made may be instantly modified from what the pilot typed in.

ISA DEV Default is 0. Enter ISA DEV if deviation at altitude are known.

PERF PLAN Goes to pages where wind entries can be made for each individual wpt if
desired.

PERF INIT pg. 5/5

BOW Basic operating Wt. is retained as default but can be modified anytime
FUEL Fuel load as sensed by the fuel system. An overriding entry can be
made.
CARGO Enter estimated cargo weight carried
PASS / @ LBS Enter number of pax. and avg. weight. ex: 4 / 160 or 7 / 210 etc..
Gulfstream IV Notes 40
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PASS WT Using the entry above the FMS calculates total passenger’s weight
GROSS WT Automatically calculated from the above entries

PERF DATA This prompt (4R) MUST be pressed to enable calculations with the data
just entered and to enable VNAV. After calculations are complete the
FMS goes to the PERF DATA pages to display first pass calculation
results of ETE and fuel reqd, reserves etc.

PERF DATA

Four (4) pages of Perf Data display computed performance values based on the PERF INIT
entries, current aircraft status, temperature conditions and proposed flight plan. Any change in
those values alters predictions.

Pg. 1/4
- Chosen cruise altitude vs possible ceiling - Step increment
- ETE to destination and alternate - Fuel required to destination & alternate

Pg. 2/4
- Entered cruise winds - Head wind or Tail wind component
- Fuel remaining at destination - Preflight plan fuel amount
- Differences between planned and actual - Updated plan

Pg. 3/4
- Chosen method of reserve calculation - Reqd vs Plan amount
- Updated plan - Differences between planned and
actual

Pg. 4/4
- Current fuel qty - Current fuel flow
- Ground speed - True airspeed
- Specific range ground miles - Specific range air miles

TAKE-OFF INIT

Take-Off Initialization is required to enable the performance computers to calculate required

runway lengths, Vspeeds and EPRs.

Pg. 1/4
- Runway & rnwy length displayed if a runway has been selected in the DEPARTURE
page of the NAV index
- Surface OAT and baro. pressure as sensed from ADC
- Runway elevation comes from the NAV database
- Surface winds are a required entry for computation of accelerate-go / accelerate-stop
distances

Pg. 2/4
- Entries of slope / clearway / stopway / and obstacle distance & elevation are optional

Pg. 3/4
- Anti-skid and spoilers ON-OFF selection and flaps setting
Gulfstream IV Notes 41
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Pg. 4/4
- Anti-ice ON-OFF and thrust (FLEX or RATED EPR setting) selection

- Calculated gross weight from PERF DATA is echoed back. An overriding weight entry is
permitted on this page.

- T.O. DATA prompt must be pressed to enable calculations from T.O. INIT data

TAKE-OFF DATA

Pg. 1/2

- T.O. weight - Runway length available vs required

- EPR - Accelerate and go distance / Accelerate and
stop distance

A “TAKEOFF OUT OF LIMITS” message is displayed if any of the following limiting conditions
are found outside of normal parameters:

- Climb - Tire speed - Field length

- Brake limitations - V1 MCG limits - Obstacle height or invalid obstacle entry

Pg. 2/2

- Displays calculated Vspeeds: V1, Vr, V2, Vfs, Vse

CLIMB/CRUISE/DESCENT

These pages will display, as appropriate, information on:

- Current Speed Command

- Top-of-climb (TOC) , Top-of-descent (TOD) or, Bottom-of-descent (BOD) target altitude
- Miles to go to TOC, TOD or BOD
- ETE / ETA to TOC, TOD or BOD
- Fuel remaining when you get to TOC, TOD or BOD
- Angle of descent
- Range / time left to reserve fuel

Notes:

1- Changing the speed command on these pages will update it in the PERF INIT pg. 2/5 also.

2- The title of the page will change appropriately to “S.E. CLIMB”, “S.E. CRUISE” or “S.E.
DESCENT” if operating on one engine. Single-engine mode is entered into by the FMS
when HP falls below 41%. The calculated drift down/up figures are calculated after the pilot
presses FLCH and AUTO on the guidance panel. Then, and only then, PERF DATA,
CLIMB, CRUISE and DESCENT pages will all reflect single-engine performance.

The S.E. CRZ CLB prompt gives figures based on flying a cruise-climb schedule
maintaining the optimum altitude for the current weight in order to stretch range as much as
possible.
Gulfstream IV Notes 42
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LAND/GA INIT

Pg. 1/3 Same as T.O. INIT 1/5 (Rwy length, OAT, Baro press. Wind, rwy elevation)

Pg. 2/3
- Anti-skid & spoilers ON-OFF selection
- Landing flap setting default of 39 deg.

Pg. 3/3
- Anti-Ice ON-OFF selection
- Calculated landing weight is displayed. Overriding pilot entry is permitted.
- The LANDING DATA prompt must be pressed for calculations to take place

LAND DATA

Pg. 1/2
- Projected landing weight - Runways length vs landing ground run
distance required
- Vref for 39 deg flap setting - Dry runway landing distance required
- Wet runway landing distance required (= 115% of ‘dry’)

Pg. 2/2
- Projected landing weight - Max landing wt
- Approach / climb speed per AFM and EPR - Landing / climb speed per AFM and
EPR

WHAT-IF-INIT / WHAT-IF-DATA

The “what-if’ option allows recalculating a flight plan based on data changed data in “What-if Init”
to see what happens if we change PERF parameters such as altitudes or speed. The pilot has
the option to reject or activate the results. As with “PERF DATA”, “what-if-data” must be pressed
to begin the calculation after new numbers are entered in ‘what-if-init’.

STORED FLIGHT PLAN INIT

The purpose of this option is to allow pilots to calculate perf. data for a possible future flight plan
in storage.

1. Select a flight plan from the list

2. Select the “STORED FPL PERF” option at 3R
3. Make the appropriate changes to the perf init pages
4. Press the “STORED FPL DATA” prompt to start the calculations.
5. Evaluate the resultant ETE and fuel required and decide accordingly
Gulfstream IV Notes 43
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NAV INDEX

Page 1/2 < FPL LIST FPL SEL > Page 2/2 < NOTAM PATTERNS >
< WPT LIST DATA BASE > < IDENT MAINTENANCE >
< DEPARTURE ARRIVAL > < POS INIT CROSS PTS >
< POS SENSORS TUNE > < DATA LOAD FLT SUM >

FPL LIST

Brings up a menu of stored flight plans, if any. This page can also be used as the starting point to
define a new flight plan by entering its name in the top LH prompt. Ex. enter KPHX-KMSP to
name the flight plan and begin the wpt input process.

FPL SEL
Selects a stored flight plan from the menu.

WPT LIST

Accesses a database of all pilot defined wpts. Also brings up prompts to define a waypoint if it
doesn’t exist.

CREATING WAYPOINTS by:

1. Name: When entering a wpt by name (1-5 letters long) in the flt plan, if unknown to
the database, the FMS defaults to the wpt definition page (same as WPT
LIST page) to let you define it. If the name already exists in the database,
the FMS will insert it in the flight plan.

2. Lat /Long: Enter Lat-Long in the scratchpad then line-select to the desired location in
flight plan. Wpt will come up as: *LL0x (*LL01 or *LL04 etc..)

3. Direct Definition: Define wpt in the scratchpad then line select to desired location. Valid
scratchpad entries can be:

ENTRY TYPE EXAMPLE WPT TYPE CDU ID

Lat-long N4805.6W09524.3 REG. WPT *LL0x
Place / Bearing / Distance LAX/095/52 REG. WPT *PBD0x
Place / Bearing / Place / Bearing PXR/240/BXK/080 INTERSECTION *RR0x
Place / Distance LAS//45 OFFSET *PB0x

The FMS will add an ‘*’, ‘&’ or ‘#’ when creating temporary waypoints. Altitude constraints can be
entered as follows: FLxxxA for an “At or above’ crossing , FLxxxB for an ‘At or below’ crossing

DATABASE Accesses all information contained in the FMS NAV database.

Gulfstream IV Notes 44
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DEPARTURE Accesses SIDs and departure transitions for a specified runway. Some
procedures are not in the database because of software definition limitations. Defined SIDs will
include altitude restrictions and insert them into the flight plan as applicable.

ARRIVAL

Accesses STARS, transitions and approaches for a specified runway. Not all procedures are
defined in the database. Defined STARs will include altitude restrictions and insert them into the
flight plan as applicable.

The FMS displays a “MISSED APRCH” prompt at 4R, 2 nm before the FAF. If the prompt is
activated the missed approach procedure is appended to the flight plan. The go-around button
will also activate the missed app. but only while the “MISSED APRCH” is displayed.

APPROACHES: GENERAL RULES

- The DGRAD light must be off the entire time.

- If the approach is published, it is very likely to be stored in the FMS. In some cases, the chart
may be published but the approach will not be stored in the FMS database because not all
approaches can be codedas published and meet guidance accuracy standards. Only straight-in
apps. are stored. No “circling only” approaches are stored .

- Jepp is moving away from using cryptic acronyms (ex: FA03, CD12, etc..). Those were used
because of memory limitations in the past.

- Software upgrades will be available in the near future allowing the symbol generators to draw
the proper curves & symbology for: DME arcs, Teardrops & Course reversal turns.

The FMS is not certified to fly Localizer or ILS approaches because of the .3NM accuracy error
tolerance certification which is far below the accuracy of a LOC / ILS setup. SLS / Differential
GPS cures that problem and is already in use at certain airports. All other approaches are
available as either GPS overlays or stand-alone.

IMPORTANT: Although users can type in “known” fixes to make their own approach up from a
chart when the approach is not stored, those approaches are NOT LEGAL to fly in IFR weather.
All approaches flown with the FMS must be flown from data stored in the database.

GPS APPROACHES

- GPS approaches are still considered NON-PRECISION approaches

- RAIM must be valid (.3 nm accuracy std is met) in which case the approach light will come on.

- The approach chart must state “GPS” on the chart (ex: “GPS 25” or “VOR or GPS 7R”) to be
legal

- If RAIM becomes invalid during the approach the system will immediately switch back to
DME/DME or VOR/DME scanning and the approach cannot be pursued as GPS-based.

- GPS Stand-Alone approaches: - Non-GPS alternate approach is required

- Missed approach must not be GPS-based
Gulfstream IV Notes 45
Revision 2-98 Avionics

- ‘Overlay’ approaches: - VHF / LF navaid monitoring not required

- Limited to VOR, VOR/DME, NDB, NDB/DME, and RNAV

Missed Approaches

On non-precision approaches terminating at the runway, the stored MAP is computed as

threshold altitude + 50 feet. This usually makes up a 3 deg slope from the FAF but may not meet
the MDA at MAP. It is up to the crew to verify & enter the proper altitudes on the ALTITUDE
SELECTOR on each wpt of the approach in the CDU.

The MISSED APPROACH prompt is displayed in the scratchpad 2 NM or so before the FAF on
the active flp page. If the “MISSED APPR” prompt or the “TOGA” button is pressed, the missed
approach segment is activated and appended to the flight plan after the MAP. At this point the
crew should have the altitude selector already set for the next altitude if using FMS guidance in
the climb-out is intended.

POS SENSORS

Gives access the several pages of information about sensor status. FMS position be manually
updated and IRS / GPS sensors can be queried to find what position / groundspeed / drift from
FMS pos. they think they are at. GPS status allows access to current RAIM , destination RAIM
and predictive RAIM information.

The FMS uses whatever sensor gives the most accurate information. This means that GPS is
used almost exclusively until a localizer-based approach is selected. It still keeps track of
DME/DME position thru autotuning but will use that only if GPS becomes unreliable. The FMS
constantly keeps track of IRS position drift and applies a correction factor called the ‘bias’. If GPS
and DME are not available the FMS will use a blend of IRS positions with their bias factor.

TUNE

The TUNE page allows pilots to hard select a freq. to a specific radio. Tuning a radio can be done
by either typing in the frequency or the identifier of the desired station (115.6 or PXR for the
Phoenix VOR.) This can also be done on the PROGRESS pg. 1/3. Selecting one of the prompt
will display the 6 closest stations of the type chosen. (“NAV” shows 6 VOR frees. “ADF” the 6
closest Nabs etc..). The RADIO CONFIG page is used to define the radio setup in the aircraft.
(MAINTENANCE  go to MAINTENANCE pg. 2/3  SETUP  RADIO CONFIG).

ABOUT LETTERS Next To The RADIOS FREQUENCY On The RADIO TUNING &
PROGRESS Pages

A  “auto” :: when FMS is auto-tuning

V  “VOR mode” :: If FMS was autotuning and V/L is pressed, autotuning is suspended while in
VOR / LOC
mode and will resume when “FMS” is pressed again on the display controller

R  “remote tuning” : tuning frequencies thru the FMS

M  “Manual tuning” : Tuning from radio controls themselves

How to restore autotuning again ?  just delete the non-A letter

Gulfstream IV Notes 46
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NAV INDEX Pg. 2/2

NOTAM

Allows deselecting a VOR in advance to prevent the FMS from using it for position computations.
The ‘permanent’ column keeps the VOR deselected until it is deleted from there. The “temporary’
column restores the VOR at power-down.

PATTERNS
HOLDING PATTERNS

Press the DIR key, then ‘PATTERNS’, select HOLD from the menu then line-select the wpt on
which you desire to hold. After defining the HOLD on its definition page press “ACTIVATE”. An
“EXIT HOLD” prompt appears in the scratchpad as soon as the hold is entered. Pressing this
prompt causes a “RESUME HOLD” prompt to appear, turns the plane toward the fix then fly to
the next wpt on the flt plan. If you press “RESUME HOLD”, the exit is canceled and the hold
continues.

Holds that are part of an approach as a course reversal are executed only once then the airplane
proceeds with the approach by itself.

To Hold At Your “Current Position”: Press DIR, PATTERNS, HOLD, then line-select the 1L
key, which is our ‘current position”. The FMS immediately turns the airplane to a standard hold
on course.

ORBITS: Orbits around a fix. Pilot determines: the fix, CW / CCW rotation, speed & radius
in NM. When leaving the orbit, the FMS will re-intercept the outbound course from
current position. It will not fly over the fix one last time as when leaving a holding
pattern.

PCDR TURN: Available only when coded for an approach in the database. New procedure
turns cannot be created, the outbound distance and turn angle can be modified but not
the inbound course

RADIAL: Allows interception of radial ‘XXX’ TO a VOR then exit via radial “YYY” FROM it

FLYOVER: Inhibits turn anticipation thus forcing the aircraft to fly over the wpt before turning.

ARCS: Not selectable from the pattern menu but the FMS will readily intercept ARCs
that are part of the transition to an approach. To fly an arc :

Press DIR, INTERCEPT and line select the end of the arc (wpt nearest the runway with an
inverse video “A”). Choose either a COURSE or HDG SELECT from a wpt preceding the arc
interception point to enable a smooth transition in case going direct to the arc were to cause too
sharp a turn. A course direct to the beginning of the arc intercept point is possible at all times.
(see illustration on next page)
Gulfstream IV Notes 47
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runway FA07A 2nd ‘A’ (final approach fix: select that

one)


CA07A


1st “A”

IDENT

The ‘power-up ‘ page. Displays the software version, active database date ranges, current time /
date and database diskette ID.

MAINTENANCE

Maintenance Pg. 1/3

CONFIGURATION CHANGES vs OPERATING:

DUAL: All commands and entries transfer automatically between FMS’es

INITIATED XFER: All commands and entries transfer between FMS’es AFTER
confirmation thru a prompt on the last page of the flight plan (press
‘FPL’ then ‘PREV’ & ‘PREV’ as the quickest way to get to it usually).

INDEPENDENT: No commands or entries are automatically transferred except for radio

tuning commands

SINGLE: No data is transferred between FMS’es

CONFIG PROBLEMS: Displays places to look for a problem when “configuration” differs from
“operating”

MAINTENANCE Pg. 2/3

- FAILED SENSORS Lists all currently failed sensors.

- SENSOR HISTORY Lists sensors that have failed during the current flight.

- SETUP:

RADIO CONFIG: allows defining radio setup used in the cockpit that can be
remotely tuned by the FMS
Gulfstream IV Notes 48
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FLIGHT CONFIG 1/2: Allows setting bank factor, automatic page turning and whether
the origin / destination shows up all the time on the EFIS (special
software may be needed to enable EFIS to use this input).

FLIGHT CONFIG 2/2: Allows turning ‘special missions’ ON (to get patterns other than
HOLD and Proc. Turns).
Setting Gen Bus #2 to a particular application
and turning “SMARTPERF” ON/OFF.

ENGR DATA: Accesses various prompts to be used under Honeywell’s

directions to analyze FMS problems.

MAINTENANCE Pg. 3/3:

- Active heading mode (TRUE or MAG) - Selected heading mode

POS INIT

- LAST POS The last FMS position. Pressing ‘load’ at 1R inits the FMS there.
- REF WPT Can be an airport ICAO ID (KDFW, LFPG, P19 etc...), a runway
threshold or a ‘RAMPX’ waypoint.

CROSS POINTS

- PPOS DIR : course TO, in relation to a fix (+ ETE and fuel remaining when we get
there)
- CROSS RADIAL : where will we cross a desired radial from selected VOR or wpt
- EQ TIME PT : equal time point between 2 entered wpts
- LAT/LON : course, dist, ETE to cross a given lat / long (+fuel remaining once at
that wpt)
- PT ABEAM : where along the flt plan we would cross abeam of the entered point
- PT-NO-RTN : point of no return (dist, ETE, fuel) to any entered wpt

Data on the Point-of-no-Return page is updated only when that page is selected. You will notice
that the data does not change. You have to leave the page and come back. The possible wind
entry does not change the internal wind model created with sensing + Perf init + wind entries at
wpts.

DATABASE & LOADER ISSUES

CUSTOM DATABASE: - WPT LIST + FLT PLANS

- up to 200 pilot-defined wpts
- can be transferred to the other side in flight

- DL-900’s can upload / download data. Older DL-800 data loaders need mod-C & D to
download files
Gulfstream IV Notes 49
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- FMS navigation database cannot be cross-loaded in flight...only the CUSTOM database.

Cross-loading NAV databases is very slow as this is not a primary function of the ASCB circuit it
is much quicker to load side 1 then side 2.

FLIGHT SUMMARY

- Take-off time, enroute time, Landing time - Fuel used, Average TAS / GS
- Air distance covered - Ground distance covered

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

DIRECT Key (causes 3 prompts to appear: DIRECT, PATTERN, INTERCEPT)

D I R E C T:

To do a “Lateral” or LNAV direct to another waypoint at our current altitude:

 Press DIR

 Press the key next to the waypoint (on the LH side of the CDU)
wpt is not already in the flight plan, simply type the name in the scratchpad then
line
 If the desired -select it to the dashed line prompt. If wpt is not found in the
database, the system will automatically take you to the waypoint creation
page in order to define it, then you can fly direct to it.

To do a “Vertical” or VNAV direct:

 Verify that the altitude selector knob is set to the new desired altitude

 Enter that desired altitude for the particular wpt on the RH side of the CDU

 Press DIR then press the line-select key next to the desired altitude and
BINGO!

 All wpts between our current position and the “direct-to” wpt are deleted from
the flt plan. If recovery of deleted wpts is needed: press DIR then the PREV
key, you will se a wpt list on a” -1 page”. Select the wpt(s) and they will be
brought back at the proper place in the flight plan sequence.

 The system will not respond to a “VNAV direct” unless the altitude selector is
set above your current altitude if a climb is commanded or, below your
current altitude if a descent is commanded.
 The glide slope flown to the DIR waypoint will be whatever you entered on
PERF INIT pg. 2

CREATING RUNWAY CENTERLINE EXTENSIONS

This is very useful to intercept runway XYZ centerline “X” many miles out on final.
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1. Select a runway at the dest. airport from the ARRIVAL page, if not already done
2. “Line select” that runway, (to bring it to the scratchpad)
3. Add in the desired distance at the end of the entry on the scratchpad
4. Line select the whole scratchpad content back on top of the original runway on the
CDU

Example: Creating a waypoint 3 miles on final for RW06L at KLAX

after line-selecting the runway entry on the CDU, the FMS will puts: KLAX.RW06L / 242 / in the
S/Pad and waits for you to complete the entry with a distance.

Bearing ‘242’ for RW06L comes from the FMS calculating the wpt position from the runway
threshold towards the point on final. We want the wpt 3 miles out, so an ‘3’ completes the entry:
“KLAX.RW06L / 242 / 3”. Line selecting this on top of the runway ID, on the CDU LH side,
inserts the new wpt and moves the runway down one line on the CDU. We have thus created a
“PBD0X” (Place Bearing Distance wpt 0x ) 3 NM out on final for RW06L at LAX. An altitude can
also be entered on the extended centerline wpt in order to enable a VNAV descent down to that
point. Either a VPTH or VFLC will work.

Rwy 06L
PBD05 3NM out

062 deg 242deg

FMS VNAV

- Uses speed commands entered in PERF INIT pg. 2

- Proper altitudes must be entered at designated waypoints in order to create continuity using
VPTH
- Will not fly thru the ALTITUDE SELECTOR regardless of wpt altitudes

- Going too fast in FLCH or VFLCH may result in LATCHED SPEED. If in VPATH and CAS >
Vmo-5, the FMS will switch to VFLCH, raise the nose to avoid overspeed and use Vmo-10 in
the descent. The FMS enters this mode automatically (“LATCHED SPEED” appears on the CDU
instead of your speed command) but the mode can be deleted by line-selecting a “DELETE” to
it and entering a different speed command.

See Section 7 “Flight Plan” in the pilot manual for in-depth VNAV explanations
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VNAV Offset Waypoints

Allows creating an intercept point ‘xx’ miles before -or- after a given wpt on our current course so
that an altitude can also be entered at that wpt to allow a VNAV climb / descent to it

ABC DEF PB01 ABC

DEF
  becomes  


enter “ABC//20 ” (or “ //20 ”) and line-select it on top of ABC to create a “PB0x” (Place-Distance)
point on the current course before ABC then enter a specific altitude at that point if a descent to
it is needed.

Lateral Offsets

Used to fly parallel to a desired track by XX.X miles.

To enter one: Go to PROGRESS pg. 3/3 and enter a desired distance at the top right (1R)
prompt.
To delete one: Go to PROGRESS pg. 3/3 , press DELETE then the 1R key

Offsets are automatically cancelled for course changes > 90deg. , starting any SIDs or STARs,
holds or intercepts. An “OFFSET CANCEL NEXT WPT” message is displayed before an offset
is autodeleted.

>>>> G P S <<<<
GPS RAIM (Receiver Autonomous Integrity Monitoring)

Calculation scheme indicating whether satisfactory satellite orbit geometry is or will be available
to ensure required signal accuracy during certain phases of flight. FMS shows a “YES/NO”
answer format.

For RAIM prediction at our arrival time: POS SENSOR  GPS ‘X’ STATUS  PRED RAIM
For a breakdown in 5 min. chunks from ETA - 15 min to ETA + 15 min: do the above then 
DEST

Phase of Flight GPS RAIM Limits

Departure / Terminal 1.0
Enroute/Oceanic 2.0
Approach 0.3
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>> DEFINITIONS <<

Supplemental

A navigation system that must be used in conjunction with a sole-means navigation system.
Approval for supplemental-means for a given flight phase requires that a sole-means navigation
system for that phase of flight must be onboard.

A supplemental means navigation system must meet the same accuracy and integrity
requirements as a sole-means navigation system; there is no requirement to meet availability and
continuity requirements. Operationally, while accuracy and integrity requirements are being met,
a supplemental-means system can be used without any cross-check with the sole-means system.

GPS is approved as supplemental when IRS’s or VLF Omega are installed. (TSO C129 B1/C1,
AC20-130a)

Sole Means

A navigation system which, for a given phase of flight, meets all four navigation system
performance requirements: accuracy, integrity, availability, and continuity of service. Any sole-
means navigation system could include one or several sensors, possibly of different types.

Primary Means

A navigation system approved for a given operation or phase of flight that must meet accuracy
and integrity requirements, but need not meet full availability and continuity of service
requirements. Safety is achieved by limiting flights to specific time periods and through
appropriate procedural restrictions.

Aircraft flying with only 2 GPS’es only as primary NAV means for crossing the ocean must
determine whether FDE “Fault Detection and Exclusion” criteria are met before departure. FDE
is not RAIM, it verifies whether you will have satisfactory RAIM for the WHOLE flight. The
“exclusion” part means that a bad satellite can be excluded from the list of satellites in view for
NAV purposes by certain model FMS or GPS-only navigators.

FDE cannot be calculated by the FMS itself at the present. A PC program “Sure Flight” supplied
by Canadian Marconi must be run to verify that FDE is OK. This is an FAA rule for dispatch
requirement...

GPS is approved as Primary Means thru TSO C129 B1/C1, AC20-130a and when FAA notice
8110.6 criteria are met and local FSDO approves. There is no requirement to have a sole-means
navigation system on board to support a primary means system.

Primary Means Oceanic/Remote

Compliance with required performance: - Does its own FDE (Detect and exclude failed satellites)
- Crew annunciation of loss of GPS navigation
- Display of real-time RAIM
- FDE prediction for dispatch
- DR mode with < 14NM/hr drift

(End of Jean-Guy’s notes.)

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INERTIAL REFERENCE UNITS (IRU)

The term IRU for inertial reference unit and IRS for inertial reference system are used
interchangably in GIV terminology and in these notes. IRU refers to a dedicated inertial
reference based position sensor that provides information to a navigation computer such
as an FMS or LaserTrak. An IRS is a navigation system that combines an inertial
reference platform with a dedicated navigation computer in one unit.

ALIGNMENT:

On power-up, go straight from OFF to NAV position

Placing in ALIGN first does not improve accuracy and if left in ALIGN for too long, may
actually degrade performance.

Old mechanical gimbaled gyros became more accurate with time in ALIGN -- does not help
laser gyros.

Minimize aircraft movement during alignment.

If possible, perform alignment with A/C headed in general direction of flight.

(GAC Breakfast Minutes -- 01/18/94)

IRU POWER SOURCES

Priority 2nd 3rd 4th

IRU 1: L Main AC L Main DC Essential DC IRU Battery

IRU 2: R Main AC R Main DC IRU Battery
IRU 3 (AHRS): L Main AC L Main DC IRU Battery

Will get a blue "IRS ON DC" CAS message if Main AC power is lost

IRU endurance on IRS battery is 20-40 minutes

IRU START UP BATTERY TEST

A normal "BATTERY FAIL" light will come on at 19 VDC

"BATTERY FAIL" light is a latching type light

Will remain illuminated regardless of battery condition until power is removed

Gulfstream IV Notes 54
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A failed battery could cause the "ALIGN" & "ON BAT" lights to flash back and forth on
the IRU control panel

In this situation, the IRU will not come online

To bring the affected IRU online in a remote location:

 Power down the system

 Pull the IRU Battery out of the rack
 Power up the IRU (should align without the backup battery)
 With IRU aligned, re-rack the IRU Battery (it may charge)

IRU ALIGN LIGHT IN FLIGHT

Cannot re-align in flight

Select Attitude Mode

 20 seconds later, align light will go out.

 Heading will go to 360o.
 Must set heading to the magnetic heading indicated on the DDRMI.

Note: Do not reset the DBDI (DDRMI) on the same side as an IRU in the align mode (it
will show an amber “STBY” annunciation). A reset will force the DBDI to leave the
magnetic compass mode and slave to the directional gyro that has no magnetic reference.
(See DBDI on page 56.)

IRU #1 FAILURE

DU #1 will show ATT/HDG FAIL annunciation

DBDI #1 will give an amber “STBY” annunciation (indicating that the DBDI is using the
Flux Valve magnetic source).

Select IRU #3 on the Display Controller

DBDI #1 will auto-select IRU #3 as it's source and show a green "AHRS" annunciation

IRU COOLING FAN FAILURE

"IRS 1-2 COOL FAIL" or "AHRS COOL FAIL" (IRS #3 still uses AHRS designation)

Indicates a cooling fan failure

Honeywell manual says if within 30 minutes of destination, leave on

Gulfstream IV Notes 55
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Otherwise turn affected IRU OFF

If IRU overheats -- errors will start occurring

IRS MONITOR

The FGC compares the outputs of IRS's #1 & #2 and when there is a disagreement,
checks with the IRS Monitor in IRS #3.

The IRS Monitor compares both IRS outputs to the output of IRS #3 (or AHRS).

The IRS monitor then reports to the FGC which IRS most closely agrees with #3.

The FGC then disregards the erroneous IRS output.

BLUE "IRS MISCOMPARE" LIGHT

Indicates a discrepancy between IRS's #1 and #2 that cannot be resolved by the Flight
Guidance Computer.

With a failed IRS monitor, the FGC will not know which IRS is correct

FGC will disconnect the autopilot and yaw damper

To get the autopilot/yaw damper back:

 Manually compare the IRS's to determine which is bad

 Turn OFF the bad IRS

MEL WITH REGARD TO IRS'S

Need 2 of 3 IRS's to dispatch

If IRS #1 or #2 is failed, must stay within one hour of suitable landing field

IRS #3 (or AHRS) is best to lose

With IRS #3 failed, the IRS monitor is not available

If an IRS miscompare occurs, autopilot & yaw damper will be lost until the bad IRS
is manually determined and turned OFF

IRUs have a high false removal rate.

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DIGITAL BEARING DISTANCE INDICATOR (DBDI OR

DDRMI)
Powered by essential DC Bus
Three sources of directional information

DIRECTIONAL SIGNAL SOURCES:

Priority Source Indication

1. Own side IRS No lights

2. IRS 3 Green "AHDG"
3. Flux valve Amber "STDBY"

Automatically cycles down in priority

Will not cycle back up as higher priority sources become available

Red "STBY" light -- flux valve has failed

Continues to take directional information from own side IRS or IRS #3 as long as
available

If the DBDI's own side IRS goes to Attitude Mode, the DBDI will automatically switch
to IRS #3 or AHRS with green "AHDG" light illuminated on DBDI

If IRS #3 (AHRS) fails, DBDI will then automatically switch to flux valve reference
(magnetic heading) and show an amber "STBY" light

Pushing the reset button will return the DBDI directional reference to the own side IRS
(which is in Attitude Mode) and will indicate the IRS's directional gyro heading which
may not be a magnetic heading

When IRS #1 or #2 is in the "ATT" mode, the on side DBDI should be left in the
green “AHDG” or amber "STBY" mode to maintain a magnetic heading reference
from which to set the directional gyro from

If a reset of the DBDI occurs, the DBDI will slave to the IRS now in DG mode with
no magnetic reference

Do the following to return the DBDI to flux valve mode:

Pull "DDRMI 1 or 2" (may be labeled "DBDI 1 or 2") CB and reset

Gulfstream IV Notes 57
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Note: "DDRMI E" (or "DBDI E") CB connects the DBDI to the E-Batt. Pulling this CB
has no effect if DBDI is operating off of normal Essential DC Bus.

SPZ-8000
AVIONICS STANDARD COMMUNICATIONS BUS (ASCB)

The ASCB has two channels: ASCB 1 and ASCB 2.

If one fails there is no message of failure

ASCB FAILURE

In the case of complete ASCB failure, attitude and heading signals come directly from
sources to symbol generators.

Nav displays revert to Nav 1 and Nav 2 respectively with direct signals from sources.

DATA ACQUISTION UNITS (DAU)

Each of the two Data Acquisition Units has two channels.

DAU channels 1A and 2A are powered by ASCB Channel 1.

DAU channels 1B and 2B are powered by ASCB Channel 2.

If DAU 1A fails, check DAU 2A to ensure that the failure is not due to the failure
of ASCB Channel 1.

If DAU 2A has also failed, the actual failure is ASCB Channel 1.

- Or -
If DAU 1B and 2B has failed, the failure is ASCB Channel 2.

So, two “A” failures indicates the ASCB Channel 1 has failed.

Two “B” failures indicates that the ASCB Channel 2 has failed.

DAU MISCOMPARE

The DAU miscompare will occur when the data on DAU channel 1A does not match the
data on DAU channel 1B (and the same for channels 2A and 2B).
Gulfstream IV Notes 58
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In the case of a DAU miscompare, check the active channel engine instrument readings
against the standby engine instrument display. If they match, select the inactive DAU
channel and again compare the readings. Select the most accurate channel for display.

The standby engine instrument panel receives its engine information directly from
the sensors. It does not pass through the DAUs.

DAU CHANNEL FAILURE

It is possible for a single DAU channel to fail and freeze the output.

When engine power is changed (a climb or descent is initiated or a level off occurs), the
active DAU channel that is frozen will remain fixed, the autothrottles will disengage, and
the power lever and gauges associated with the functioning DAU will respond properly.
The power lever and the gauges associated with the frozen DAU output will remain fixed
at the previous setting.

If it is the left power lever that remains fixed, select DAU 1B channel and normal
function should return. For the right side, select DAU 2A as the active channel.

DISPLAY UNITS (DU'S)

Display Unit Screen Burn In -- DU's are experiencing screen burn in causing fixed images in the
phosphors

Can increase screen life by rotating DU locations during 150 hour DU filter changes
(GAC Breakfast Minutes -- 09/24/91)

By reducing the power to the DU’s, via the display brightness panel, there is a direct relationship
of lower power levels to improved CRT life.
(GAC Breakfast Minutes – 09/01/96)

DISPLAY UNIT POWER SOURCES

All even numbered DUs are powered by the Right Main DC Bus.
DU #5 is powered by the Left Main DC Bus.
DUs #1 & 3 are powered by the Essential DC Bus.
Gulfstream IV Notes 59
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Essential DC Bus Failure

DU
X
DU DU DU DU
#1 #2 #3 #5 #6

DU
#4

Left Main DC Bus Failure

DU DU
XDU DU DU
#1 #2 #3 #5 #6

XDU
#4
Gulfstream IV Notes 60
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Right Main DC Bus Failure

DU DU DU
X DU DU
#1 #2 #3 #5 #6

DU
#4

DISPLAY UNIT AVAILABILITY WITH DUAL CONVERTER FAILURE

After a dual converter failure only DU #1 will remain ON

DU #3 will Red-X -- can recover DU #3 by:

 Switch symbol generator controls to norm/alternate/alternate

 Select EICAS top compact to see warning messages
 Models before SN 1120 go to top compact automatically (Auto Top
Compact) when Standby Electrical Power System is ON and Standby Elect
System TRU switch pushed ON

The Hydraulic System and EVM displays are not available in the top compact
mode.

Can deselect top compact mode by turning OFF STBY TRU temporarily to
check normal DU #3 display.

ASC 240 disables Auto Top Compact in the early aircraft

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SYMBOL GENERATORS (SG’S)

Switches positioned: 1 -- 3-- 2

SG #1 normally supplies DU's 1 & 2, SG 3 -- DU's 3 & 4, SG 2 -- DU's 5 & 6

SYMBOL GENERATION FAILURE

DU Red-X’ing -- When a Symbol Generator fails, the DU's being supplied by that SG
will show Red-X's across a blank screen if the DU itself is powered. Failure of SG #1
would normally result in DU's 1 & 2 Red X’ing. It is likely for a Symbol Generator to
have a partial failure resulting in a single DU Red X’ing.

Bus Controller Failure -- There are three ASCB bus controllers. They are located in
each of the three symbol generators. When a symbol generator fails, expect to see a the
associated bus controller failure indication also.

Alternate Symbol Generator Selections

The Captain’s DU’s fall back to SG #3 when SG #1fails..

The F/O’s DU’s fall back to SG #3 when SG #2 fails.
The EICAS DU’s fall back on SG #2 when SG #3 fails.
A failure of two SG’s would cause the remaining SG to power all six tubes and be
controlled by the pilot’s Display Controller Panel.

A failure of SG #3 would cause SG #2 to supply DU's 3, 4, 5 & 6.

Display Unit Reversion Testing -- Each pilot should perform reversionary testing once a
month to stay familiar.

Power Sources:

DU# Ess Bus Left Main DC Right Main DC

1 (PFD) X
2 (ND) X
3 (EI) X
4 (CAS) X
5 (ND) X
6 (PFD) X

SG# Ess Bus Left Main DC Right Main DC

1 X
2 X
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3 X

DU STATUS WITH A DEAD ESSENTIAL DC BUS

Main DC Buses powered/Standby Electrical Power System -- OFF

DU# Status Note

1 (PFD) Tube dead DU #1 on Ess DC

2 (ND) SG dead (Red-X'ed) SG #1 on Ess DC
3 (EI) Tube dead DU #3 on Ess DC
4 (CAS) OK
5 (ND) OK
6 (PFD) OK

DU STATUS WITH MAIN DC BUSSES AND STANDBY ELECTRICAL POWER

SYSTEM POWERED

DU # Status Note

1 (PFD) OK
2 (ND) Tube dead Due to the way system is wired
3 (EI) OK
4 (CAS) OK
5 (ND) OK
6 (PFD) OK

COMPARISON MONITOR ANNUNCIATIONS

The Comparison Monitor is a function of the Symbol Generators

Amber indications (Displays on both pilots PFD's)

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DIFFERENCE
INDIC COMPARES THRESHOLD SOURCE

PITCH Pitch 6 IRS

ROLL Roll 6 IRS
HDG Heading 6 IRS
ATT Both pitch and roll greater than difference threshold.

IAS A/S Indications 20 KIAS/ DADC

MACH A/S Indications .01 mach "
ALT Altimeters 200' "
LOC Localizer ½ Dot Nav receivers
GS Glide slope Dot " "
ILS Both LOC and GS greater than difference threshold.

FWC Red Msgs Red Msg FWC (One FWC shows red msg
and other doesn’t)

ENG EPR 0.5 EPR FWC

TGT 50 TGT "
RPM 5% LP/HP "

DU 4 DU 4 input Any difference FWC

vs. Output

WHAT TO DO:

Pitch/Roll/Heading: Compare against standby instruments. Ignore the instrument that

doesn't agree.

DADC: Find bad DADC by checking both sides against standby

instruments. Isolate the bad DADC (see DADC miscompare page
77).

Altitude: Check altimeter pressure settings on both sides for agreement

against the standby altimeter.

Localizer: Check VOR frequencies

Glideslope: Check altitude crossing the outer marker and ignore bad GS

DU-4: Information being sent to DU-4 for display is not all being
displayed.

FWC: An amber FWC miscompare message indicates that the non-

active FWC has a red message displayed that is not displayed on
the EICAS DU #4 by the active FWC. Select the other FWC
(normally #2) and check for new red messages.
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ENG: Cross check EICAS engine readouts against standby engine

instruments and switch to other DAU Channel for those that don't
agree. (The standby engine instrument signals do not go thru the
symbol generators.)

Red "CHK PFD" IRS attitude output signal to the PFD is not the same as the
feedback attitude signal from the PFD to the FWC. The PFD may
be displaying false attitude information. Cross check other
sources.

Comparison Monitor Msg's On Top of the PFD

Amber "FD": Failed Flight Director

Normally a Failed Flight Director will autochange with no monitor indication

This indication can also be caused by a failed ASCB

In this case, it is not a valid indication

If the Flight Director is failed, the Autopilot will not work

Functions thru the FD

(FD will work with a failed Autopilot)

If an Flight Director fails and neither is boxed in the Display Controller, check and cycle
the following CB's on the CPO CB panel:

A7, B7, C7

Amber "AT"

Auto throttle has failed

Will not auto change -- select AT 2 from Display Controller.

Power Supply -- Autothrottle circuit board shares same case and power supply as
Performance Computer.

INSTRUMENT RED-X PROBLEMS:

1 Red-X’s on: AOA

Cause:  Flap Handle out of detent -- RESET

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 Check if Flap Control CB out (if out try to reset)

 Emergency Flap Switch -- ON

2 Red-X’s on: Altimeter/Vertical Speed

Cause: Pressure set knob max’ed out -- RESET

3 Red-X’s on: Altimeter/Airspeed/AOA

Cause: AOA vanes stick full up or down -- hit AOA Test

This occurs on A/C with 500 hrs plus

(Memory device: three “Red-X’s = Three Letters: “AOA” vane stuck.)

4 Red-X’s on: Altimeter/Airspeed/Vertical Speed/AOA

Cause: DADC failure

(Memory device: Four “Red X’s” = Four Letters: “DADC”)

Summary: 1 Red-X...........Flaps related.

2 Red-X’s........Altimeter pressure set knob maxed.
3 Red-X’s........AOA Vane stuck full up or down.
4 Red-X’s........DADC failure.

FLIGHT GUIDANCE COMPUTER (FGC)

FGC #1 is normally primary.

Will autochange to FGC #2

GIV - Stuck Pilot’s Autopilot Disconnect Switch Causes Stall Barrier and FGC
Problems
On a recent international trip, a GIV operator experienced a Stall Barrier No. 1 problem and a No.
2 Flight Guidance Computer (FGC) failure. Technicians cleaned and repeatedly actuated the
disconnect switch to unstick it, which returned the system to normal operation. The switch was
later replaced.
(GAC Breakfast Minutes – 09/23/97)

FLIGHT DIRECTOR (FD)

Testing of A/P disconnect tone and warning lights simultaneously may burnout FGCP
Gulfstream IV Notes 66
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There have been some FGC failures in turbulence

Trim wheel vibrations have forced disconnect

Solution is to desensitize this disconnect sensor

TAKEOFF MODE

Takeoff thrust and v-speed display maintained until:

400' AGL and a vertical mode selected

Then climb thrust is set and Vref for current weight and configuration is displayed.

To hold T/O V-speeds past this point, box speeds on Flight Ref page.

To hold T/O thrust past this point, box thrust on TRS page.

APPROACH MODE

Auto Approach Speed Schedule:

Within 20 NM of a/p 240 KTS

Flaps 10 180 KTS
Flaps 20 160 KTS
W/ flaps 39 Vref + 10 KTS

After leaving T/O mode, Vref is always computed and displayed on speed tape for current
weight and configuration

Landing Initialization gives additional data:

 Projected landing weight/max landing weight

 Vref for landing weight and configuration
 Runway distance required
 Pt 135 factors dry and wet
 Approach and landing climb speeds
 Climb EPR

False Localizer Capture -- Has occurred by flight director with CDI at full scale
displacement

On capture, check CDI and call "CDI CHECKED"

(FSI Inter-Office Memo -- 06/10/91)
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Premature Localizer Capture -- Occurs at certain airports with siting problems and when voltage
is down

HPN and MSP are such sites

Problem is high signal microvolt capture threshold of flight director to allow smooth capture
without overshoot

Set at 200 microvolts

Will be adjusted to 175 microvolts to reduce (but not eliminate) premature captures
GAC recommends delaying arming of approach mode until at one dot deflection and double
checking CDI centered on capture.
(GAC Breakfast Minutes -- 10/08/91)

FAULT WARNING COMPUTER

TREND LIMIT MONITORING (TLM)

A function of the SPZ-8000 and SPZ-8400 system Fault Warning Computers

The TLM system makes regular recordings of aircraft system parameters and monitors
for exceedances.

TLM DOWNLOAD
System data recorded by the TLM system is stored in non-volatile solid-state memory
independently in each of the FWCs.

GAC recommends that the TLM data memory be downloaded every 28 days immediately
after the database update.

PARAMETERS MONITORED FOR EXCEEDANCES:

 TGT
 LP RPM
 HP RPM
 Engine Fire Warning
 APU Fire Warning
 EVM (SPZ-8400 only)

EXCEEDANCES

The most common exceedence -- LP RPM

LP RPM greater than 95.5% longer than 20 seconds

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More likely:  At high elevation airports (Aspen is a common location.)

 During tailwind takeoffs.
 Failure to select FLCH vertical mode after takeoff.

Autothrottles only watch EPR limits -- not TGT and RPM

The most common scenario is a take-off from a high elevation airport with a continuous
climb requirement (terrain clearance) or no ATC restriction to climb (both common out
west). The takeoff power setting is within the normal rated EPR takeoff power. As the
climb out continues, the LP RPM will increase with altitude at a fixed power lever
position. If the power levers are not retarded to maintain LP RPM at or below 95.5%, an
exceedance will occur after 20 seconds above 95.5% LP RPM.

Note: Exceedance timing starts at any value above max continuous for the monitored
items.

RED EXCEEDANCE WARNING

SPZ-8000 Modification U. A modification exists that will display a red warning alert
message and sound a warning tone when a monitored exceedance value is exceeded but
before the exceedance time limit is has expired. This “heads up” warning gives the pilot
an opportunity to correct the problem before the exceedance times out and a permanent
exceedance is recorded, requiring maintenance action. This is a Honeywell SPZ-8000
modification, not an ASC. This feature is incorporated in the SPZ-8400 design. Previous
to this modification, the first annunciation related to an exceedance was after it had
occurred.

The benefit of this modification is obvious, giving crews sufficient warnig to avoid an
exceedance. There are several points to be considered.

The first is the fact that the message presentation is the reverse of what most
crewmembers would expect. The warning message indicating an imminent exceedance is
a red warning message: “ENGINE EXCEEDANCE”. At this point, no damage has been
done despite the color and wording of the EICAS message. If this warning is ignored and
the exceedance time limit expires, the next warning is a blue message stating: “ENGINE
EXCEEDANCE” or “EXCEEDANCE RECORD” depending on the version of software.
When this blue “advisory” message illuminates, the exceedance has occurred and is a
matter of record in the FWC TLM data storage. A maintenance inspection is now
required.

Actual exceedances in the GIV are rare. They most often occur as discussed in the
previous section. But operation in the transitional power settings where no exceedance
has occurred but exceedance timing has begun is more common. During the take-off roll
at high elevation airports, this can result in the red “ENGINE EXCEEDANCE” message
and warning tones. While it is only necessary to monitor the power or reduce power
Gulfstream IV Notes 69
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slightly, this can be very distracting at a critical time if the crewmembers are not familiar
with the reason for the warning.

BLUE AND RED ENGINE EXCEEDANCE MESSAGES

On May 7, 1996, John O’Meara gave a special Breakfast update about SPZ-8000 and SPZ-8400
Red Engine Exceedance Messages. In his presentation John mentioned that, originally, only a
blue engine exceedance message was given, to alert the crew that an exceedance had occurred
and had been recorded. During development of the SPZ-8400 system, with encouragement from
the Pilot Advisory Board, a red engine exceedance message was introduced. The red engine
exceedance message alerts the crew when the engines are in an N 1 Low Pressure (LP), N 2
High Pressure (HP), or Turbine Gas Temperature (TGT) exceedance parameter. This allows the
crew time to make engine adjustments before an actual exceedance occurs and is recorded. This
feature was introduced to the SPZ-8000 system (aircraft 1000-1252) with Mod U Fault Warning
Computers. AFM Revision 14, Appendix E, advised operators that during high elevation takeoffs
the non-flying pilot should monitor LP RPM and be ready to adjust power as necessary to avoid
exceedances. The AFM further advises that should a Red Exceedance Crew Advisory System
(CAS) message occur, an aborted takeoff should not be automatic. These steps and procedures
can be used for lower elevation takeoffs as well. Note that a red “Engine Exceedance” means the
aircraft is in an exceedance parameter for which you still have time to correct. A blue
“Exceedance Recorded” message means that the aircraft has stayed in an exceedance
parameter too long.
(GAC Breakfast Minutes – 09/23/97)

Trend and Limit Monitoring System Operator Questions Revisited

By request, we are republishing an article from GIV Service News 92-1 which noted frequently
asked questions about the GIV Trend and Limit Monitoring System and how it operates. The
questions concern data download procedures, exceedances, corrupted downloaded files, data file
name construction, and manual input of data. We have also updated and added more
information.

Q - When should the Fault Warning Computers (FWC) be downloaded?

A - (1) Due to the limited memory in the FWC, download intervals will vary depending on the
number of hours flown and the length of each flight. In order to prevent data being overwritten or
corrupted, it is suggested that a download be performed when the Nav Data Base is updated.
Nav Data Base updates are issued by Honeywell every 28 days. However, by doing a weekly
check of the FWC memory, operators can determine exactly when to do a download. (See Note
1.)

(2) Certain maintenance activities can result in a false engine or APU exceedance being
recorded. It is recommended the FWCs be disabled by pulling the FWC circuit breakers, unless
they are required for maintenance. If the FWCs are required for any maintenance task, it is
recommended a download be performed before and after the maintenance activities. The
following are a few of the maintenance activities that will input data on the FWC (aircraft in normal
ground configuration). If flight configuration is set up on the ground, additional inputs could be
generated, i.e., trend recordings and engine/APU fire exceedance recordings.

A. TGT indication Validation

B. Temperature Control System Functional Test
C. SPZ-8000 Maintenance Test (except when performing EEPROM Bit Test)
Gulfstream IV Notes 70
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(3) If during a memory usage check of the FWCs it is noted that the FWCs are not counted up
equally, then a download should be considered. The download decision would be based on
whether both FWCs were downloaded at the same time and no in-flight Essential DC Bus
operation (SPZ-8000 systems only, see Note 2) had been performed. This has occurred on a
GIV. The FWC stopped recording on its own, but after a download, it returned to normal
operation.

(4) If a facility other than your own is performing maintenance, we suggest the FWCs be
downloaded upon aircraft arrival to prevent possible loss of in-service data.

(5) If possible, a download should be done before replacing a defective FWC.

Q - Why would memory usage percentage be different?

A - (1) FWCs were downloaded at different times, i.e., one FWC was downloaded, then one or
more flights (or maintenance activity) occurred that input data before second FWC was
downloaded.

(2) One or more flights occurred where Essential DC Bus operations were conducted. The No. 2
FWC is powered by the Right Main DC Bus. (SPZ-8000 systems only - see Note 2.)

(3) The FWC stopped recording on its own. When this has occurred, the FWC returned to normal
operation after a download.

(4) FWC's memory has exceeded 100% and corrupted the data file; therefore, showing a value
less than 100%. This occurs on a random basis and cannot be identified as to which computer
would operate in this manner. Honeywell and Gulfstream are investigating this item. (SPZ-8000
FWC without Mod U - see Note 3.)

Q - We occasionally get a flashing blue data download light during some downloads we
accomplish. What causes this light?

A - A flashing blue data download light could be caused by one of the following items. In all
cases, it is necessary to correct the situation and reset the system (pull and reset FWC circuit
breakers or press master warning reset). (See Note 4.)

(1) If light occurs immediately upon selecting data download, the data disk write protection
window is open and needs to be closed.

(2) If light occurs approximately 3 minutes after selecting data download, the data disk cannot be
formatted, and a good disk must be used.

(3) If light occurs after downloading one computer and immediately upon selecting the second
computer, this is a normal situation.

Q - What causes corrupted data files?

A - (1) Input of data that is not recognized as valid data. This can occur if data is manually
inputted which exceeds the DAU values, i.e., inputting 10,000° of TGT will result in a corrupted
file due to DAU maximum value being 1,000°.

(2) A DAU miscompare during a recording has corrupted the data file on some aircraft. This was
noted only after the download and conversion had been accomplished. (SPZ-8000 FWC without
Mod U - See Note 5.)
Gulfstream IV Notes 71
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(3) FWC's memory has exceeded 100% and corrupted the data file, therefore showing a value
less than 100%. This occurs on a random basis and cannot be identified to which computer would
operate in this manner. Honeywell and Gulfstream are investigating this item. (SPZ-8000 FWC
without Mod U - See Note
5.)

Q - What must be done after the ENGINE EXCEEDANCE (SPZ-8000 FWC without Mod U) or
EXCEEDANCE RECORD (SPZ-8000 FWC with Mod U and SPZ-8400) has been displayed?

A - In all cases, except when the Engine Fire Test is depressed in flight, engine maintenance is
required. The type of exceedance and its duration determines the type of maintenance to be
done. (See Note 6.)

Q - How can data be manually inputted to the FWCs?

A - Several methods used to input data when the aircraft is on the ground are listed below. In
flight, the only method available is to select the engine fire test after 60 knots has been achieved;
otherwise, all recording will be automatic. Gulfstream released ASC 255, which allows an
operator to select a recording at any time it is desired. (ASC 255 is available and is a production
standard for aircraft 1253 and subsequent.)

CAUTION: Attempting to do any of the following with engine(s) operating will cause
invalid/erroneous engine indications, i.e., low EPR due to airspeed being inputted. Accomplish
the following with engines not operating.

(1) Connecting a test set that could generate an HP RPM, an LP RPM, or a TGT signal which
would trigger an exceedance recording.

(2) Connecting a pitot static test set, generating 60 knots or greater, and depressing either engine
fire test (engine data) or the APU fire test (APU data) to trigger an exceedance recording.

(3) Connecting a pitot static test set, applying power to all buses, cycling both start valves, and
generating 100 knots or greater. This would trigger an engine trend recording. This task would
require that the FWC memory be checked for an increase in percentage.
Note: Refer to GIV Maintenance Manual Chapter 31-2-4 for procedure.

Q - What is the correct format for the raw data filename when viewed using DOS DIR command?

A - The correct format for a valid (not corrupted) raw data file should be in a date format, i.e.,
October 10, 1991 would be presented as 101091.TL (DL-900 data loader Mod A) or 101091.DAT
(DL-900 data loader Mod B or later). Any other format indicates an incorrectly set EEPROM and
may be a corrupted file. SPZ- 8000 TLM software v. 1.5A or SPZ-8400 TLM software v. 1.0 will
recognize either file extension. (See Note 7.)

Q - We have received converted files from Gulfstream and all that is displayed is an EMPTY BOX
screen and printout. What causes this abnormality?

A - The Empty Box screen and printout is generated when a data file is corrupted and the
conversion program cannot retrieve the data. It may also be caused by an empty file, i.e.,
download did not occur as stated in the Maintenance Manual.

Q - When will the conversion program be provided?

A - Gulfstream has released to the GIV operators a program which will allow downloaded data to
be viewed or printed.
Gulfstream IV Notes 72
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If any additional information is needed on the conversion program or its use, operators may
contact Gulfstream Aerospace Corporation, CMP, M/S D-10, P.O. 2206, Savannah, Georgia
31402-2206; 912- 965-4687 (phone); 912-965-3598 (fax).

If additional information or assistance is needed, operators may contact their area Field Service
Representative, or Gulfstream Technical Operations at 912-965-3247 (phone), 912-965-4184
(fax).

Special Notes

Note 1 - SPZ-8400 FWC - The message "T&L>80%FULL" was added to inform the crew, with
WOW, that the T&L memory was greater than 80% full.

Note 2 - In the SPZ-8400 both FWCs are on the Essential Bus.

Note 3 - Fixed in -905 FWC Mod U and SPZ-8400 FWCs (both the corrupted EEPROM problem
and wraparound >100%).

Note 4 - Selecting master warning button also resets this function.

Note 5 - Both were corrected in -905 Mod U and SPZ-8400 FWCs.

Note 6 - The SPZ-8000 Mod U and SPZ-8400 FWCs activate a red "Engine Exceedance"
message that warns the pilot of an approaching exceedance condition. The message
"Exceedance Record" is displayed when the exceedance occurs and is recorded.

Note 7 - Gulfstream added reference to decode program that recognizes both .TL and .DAT file
extensions.

Known SPZ-8400 Trend and Limit Discrepancies

The following are known discrepancies with the SPZ-8400 Trend and Limit function. Gulfstream
and Honeywell are working together to resolve the conditions.

1. APU TGT Exceedance range needs modification.

2. APU Trend record is done on activation of the same switch used to activate ground power.
This results in a large number of Trend recordings when the APU is not running.
3. Brake Exceedance still trips at temperatures well below exceedance level.
4. APU RPM exceedances were specified with too little debounce.
5. Trend snapshot subsequent to bleed air manifold being pressurized.
6. Peak values for engine and APU exceedances are under evaluation.
7. Download erratic with high density diskettes.
8. Data not recorded past 50%.

The following information about the SPZ-8000 FWC 7007484-905 upgrade Mod U will be added
to GIV Maintenance Manual Chapter 31.

Red Message Added

A modification has been incorporated to this unit which changes the engine exceedance message
logic.

Modification "U" adds a red "ENGINE EXCEEDANCE" message designed to warn the pilot of an
approaching engine exceedance condition. If no action is taken and the exceedance occurs, then
a blue "EXCEEDANCE RECORD" message is displayed and the exceedance is recorded in the
Fault Warning Computer. See the following table for the new message logic.
Gulfstream IV Notes 73
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Note: This message is displayed when the exceedance occurs. This message replaced the blue
"ENGINE EXCEEDANCE" message in non-Mod U units.

Other changes incorporated in Mod U:

• APU trends are now recorded like the SPZ-8400. In particular, the recording is triggered on APU
RPMs passing 95%. The START VALVE OPEN trigger was eliminated to reduce the likelihood
of trend/limit recording during periods of marginal aircraft power (and subsequent corruption of
the T&L storage device).
• Corrected problem where intermittently the Trend & Limit data would become corrupted. This
was due to when the T&L storage device header was updated. The header is now updated
subsequent to each record event.
• Corrected a problem where the wraparound flag was not set properly. This will allow the T&L
recording to go above 100% without data corruption.
• A fix was incorporated to address the intermittent Red-X problem.

Reported problems since Mod U release:

• Intermittent Red-X problem still occurs, but at a reduced rate.

• Intermittent Bus Controller Test failures at power-up.
(GAC Service News -- April - May - June 1997)

Trend and Limit Monitoring System Exceedances

Several new GIV operators have experienced engine exceedances and had questions about
what recording and maintenance should be done. This article, updated from Gulfstream IV
Service News 92-1, provides information on the types of exceedances, general system operation,
and what should be done after an exceedance. Some of the information presented can be found
in GIV Maintenance Manual Chapter 31-2-4.

Types of Engine Exceedances and Their Recording Triggers

Note: Unless an airspeed is indicated as a requirement to trigger an exceedance (i.e., engine

fire), exceedance recording will occur regardless of the aircraft location or configuration when the
required parameters are met.
Gulfstream IV Notes 74
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SPZ-8000 Pre-Mod U

Parameter Enable Condition Blue "ENGINE Disable

Exceedance Message Condition
LP (N1) % >= 95.5 20 sec <= 95.0
>= 98.3 500 msec
HP (N2) % >= 97.5 5 min <= 97.0
>= 99.7 20 sec
>= 102.7 500 msec
TGT Deg. >= 715 5 min <= 710
>= 800 20 sec
>= 820 500 msec
Eng. Fire Active and A/S > 500 msec Inactive or
60 kts A/S
<= 60 kts
Operator Active 500 msec Inactive
Request
Snapshot
(ASC 255)

SPZ-8000 Mod U

Parameter Enable Condition Red "ENGINE Blue "EXCEEDANCE Disable

EXCEEDANCE RECORD" Message Condition
" Message
LP (N1) % >= 95.6 100 msec 20 sec <= 95.5
>= 98.4 100 msec 500 msec
HP (N2) % >= 97.6 4.75 min 5 min <= 97.5
>= 99.8 100 msec 20 sec
>= 102.8 100 msec 500 msec
TGT Deg. >= 716 4.75 min 5 min <= 715
>= 801 100 msec 20 sec
>= 821 100 msec 500 msec
Eng. Fire Active, and A/S > 100 msec 500 msec Inactive or A/S
60 kts. <= 60 kts.
Operator Active 100 msec 500 msec Inactive
Request
Snapshot
(ASC 255)
Gulfstream IV Notes 75
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SPZ-8400

Parameter Enable Red "ENGINE Blue Disable Condition

Condition EXCEEDANCE" "EXCEEDANCE
Message RECORD" Message
LP (N1) % >= 95.6 50 msec 20 sec <= 95.5
>= 98.4 50 msec 500 msec

HP (N2) % >= 97.6 4.75 min 5 min <= 97.5

>= 99.8 50 msec 20 sec
>= 102.8 50 msec 500 msec
TGT Deg. >= 716 4.75 min 5 min <= 715
>= 801 50 msec 20 sec
>= 821 50 msec 500 msec
Eng. Fire Active and A/S > 50 msec 500 msec Inactive and A/S
60 kts. <= 60 kts.
Operator Active 50 msec 500 msec Inactive
Request
Snapshot
(ASC 255)
EVM >= '0.60 ips 50 msec 500 msec <= 0.59

Engine Exceedances and Associated Cockpit Displays

The SPZ-8000 Fault Warning Computer (FWC) and SPZ-8400 FWC systems provide amber and
red engine indications for the engine parameters. On the SPZ-8000 FWC (pre-mod "U") system,
it is imperative that the pilots and ground crew monitor the engine parameters to prevent an
exceedance from being recorded. There is no message to alert the crew of an impending
recording. The SPZ-8000 FWC (mod U) and the SPZ-8400 FWC provide a red ENGINE
EXCEEDANCE message to the Engine Instrument and Crew Advisory System (EICAS) display
unit when any of the above engine parameters (not time frame) have been exceeded to provide
the crew adequate time to reduce power and avoid an exceedance recording. This message will
be displayed as long as the engine parameter(s) remain(s) in the exceedance range.

The SPZ-8000 FWC (pre-mod U) will send a blue ENGINE EXCEEDANCE message to the
EICAS display unit when any of the above exceedance parameters and time frame have been
fully recognized. The SPZ-8000 FWC (mod U) and the SPZ-8400 FWC will send a blue
EXCEEDANCE RECORD message to the EICAS display unit when any of the above exceedance
parameters and time frame have been fully recognized. These messages will flash for five
seconds, then will be displayed for five seconds and will not be repeated until the exceedance
has been disabled and another exceedance has been recognized. It is the responsibility of the
pilot (or ground crew in the case of an exceedance during a ground run) to visually identify the
engine exceedance through cockpit indications and take appropriate action to resolve the
condition. In most cases, this would require reducing power to an acceptable level at or below the
exceedance recording disable point.

The SPZ-8000 FWC (pre-mod and mod U) will send a blue ENG EXCEED RECORD message to
the EICAS display unit when the exceedance has been disabled. This message will flash for five
seconds, then will be displayed for five seconds and will not be repeated until another
exceedance has been recorded. After the exceedance has been disabled, the EICAS
EXCEEDANCE PAGE should be brought up. All data on this page should be written down and
given to maintenance personnel for appropriate action. This information is from the FWC volatile
Gulfstream IV Notes 76
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memory and is not available if a power transfer occurs after the exceedance. If this data is not
gathered, maintenance personnel should be informed of the display, and an FWC download
would be required to access the exceedance data. The Max-Time provided on the EICAS
EXCEEDANCE PAGE is NOT the time that will be used for determining maintenance
requirements (see the following section on this subject). MAINTENANCE WILL BE REQUIRED
whenever the ENGINE EXCEEDANCE or EXCEEDANCE RECORD message is displayed,
except when the Engine Fire Test, the APU Fire Test, or Snapshot switch is activated in-flight.

It is possible to have several exceedances occur at one time; however, the first exceedance
recognized will take precedence. If any other exceedance is still present when the first
exceedance is disabled, it will then be recognized. The FWC volatile memory will retain only the
last exceedance experienced; the non-volatile memory will retain all exceedances that occurred
on the aircraft. The non-volatile memory can only be accessed by doing an FWC download and
data file conversion.
Maintenance Required after Exceedance Message Is Displayed

After a pilot (or ground crew) reports an engine exceedance, all available engine information must
be obtained in order to do the appropriate maintenance. MAINTENANCE WILL BE REQUIRED
when the ENGINE EXCEEDANCE or EXCEEDANCE RECORD message is displayed, except
when the Engine Fire Test, the APU Fire Test, or Snapshot switch is activated in-flight. The
information may be obtained from the pilot (or ground crew) if he or she was able to access the
FWC volatile memory through the EICAS EXCEEDANCE PAGE. If the EICAS EXCEEDANCE
PAGE information is not available, the FWC(s) must be downloaded and the data files converted
in order to obtain the needed information. Using the EICAS EXCEEDANCE PAGE information will
allow appropriate maintenance to be done; however, the information from the downloaded and
converted FWC data file will allow a more detailed analysis of the exceedance. This is
accomplished through the 25-second recording/printout available from the FWC non-volatile
memory. The following list gives the minimum engine data required for proper maintenance:

1. Engine Affected (left, right, or both).

2. What triggered exceedance message (HP, LP, TGT, Fire)?
3. What was maximum value of exceedance?
4. What was maximum time of exceedance?
5. What was total time of exceedance?

Please note that the MAX-TIME provided on the EICAS EXCEEDANCE PAGE is NOT the time
which will be used for determining the required maintenance. Only the Max-Time provided on the
SPZ-8400 downloaded converted data file printout provides the "Total Time" of an exceedance.
The total time of the exceedance must be calculated by adding the FWC Recognition Time (time
which is used to monitor and enable the exceedance) to the Max-Time (whether from either
EICAS display or the SPZ-8000 converted data file printout).

Since it is possible to have several exceedances occur at one time, the data from both engines
should be reviewed whenever an exceedance is reported.

When all the data has been gathered, Rolls-Royce Tay Maintenance Manual Chapter 71 must be
consulted to get the correct maintenance procedure for the exceedance experienced/reported. In
the case of an engine fire, technicians must determine whether or not an actual fire occurred. If a
fire did not occur, maintenance should be done on the detection system. If a fire did occur,
appropriate maintenance on the system that caused the fire should be done. In each case, if the
fire bottle was discharged, appropriate cleanup measures must be taken (refer to TAY
Maintenance Manual Chapter 71).
(GAC Service News -- July - August - September 1997)
Gulfstream IV Notes 77
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EICAS 9.8 DIFFERENTIAL WARNING DUE TO INSULATION OVER CABIN

SENSE PORT

A GIV operator reported a situation of intermittent operation of the Engine Instrument-Crew

Advisory System (EICAS) 9.8 differential warning, following a 150-hour inspection. Technicians,
during a visual inspection, found insulation covering the input port of the cabin sense port (P/N
1159SCF407-7). On a later mission, the warning message recurred twice. Another operator noted
a similar problem with Electromagnetic Interference (EMI) from the lighting system, causing the
message to be induced. (Ref. 1/14/92 Breakfast Minutes). In the older instance the suppliers
installed mod “D” to prevent the problem recurring.

The operator in the current event replaced the unit, and they have not had the problem since.
Mod “D” is the requirement for the EMI protection.
(GAC Breakfast Minutes – 9/1/98)

APU EGT NUISANCE EXCEEDANCE MESSAGE

We have had several inquiries from operators concerning the Auxiliary Power Unit (APU) Exhaust
Gas Temperature (EGT) EXCEEDANCE message being displayed on the Crew Alerting System
(CAS) when APU air is initially selected on or during main engine start. This is a nuisance
message generated by a 680° trigger in the software for the Honeywell fault warning computers.
It is not unusual to see an EGT in excess of 680° for less than 10 seconds when loading the APU
or starting engines and this is not an actual exceedance. This item is on the list for software
update and should be corrected during the next software revision.
(GAC Breakfast Minutes – 3/10/98)

DIGITAL AIR DATA COMPUTER (DADC)

DADC FAILURE

Will be indicated by a blue "DADC FAIL" light on EICAS

The DADC failure will cause a number of amber messages

Don't chase the amber messages -- the cause is the failed DADC (blue message).

DUAL DADC FAILURE

If both fail, the following will be lost:

 Autopilot
 Autothrottles
 Flight director

DADC MISCOMPARE

A blue EICAS message.

Gulfstream IV Notes 78
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Each FMS will auto switch to the other DADC if its own fails outright

A DADC miscompare will occur if the DADC is good but is receiving bad info due to
clogged pitot-static lines

No autoswitching will occur since the system does not know which DADC is bad

Compare DADC instruments against backup instruments -- identify the bad one

Check:  Altimeter
 VSI
 A/S

GAC recommends that the standby altimeter be set to match the pilots altimeter's
altitude, not 29.92 above Transition Level.

Set the standby A/S indicator speed bug to match airspeed on pilot's A/S indicator

This will make identifying the bad DADC easier

Select good DADC on sensor page

Pull CB for bad DADC (will force the FMS to auto switch)

If this isn't done, the following will be lost as long as the Miscompare Light is
illuminated:

 A/P
 Yaw Damp
 Mach Trim

SPZ-8000: Must select the "FLT REF" button on the Flight Guidance Control Panel to
the side with the functioning DADC ("R" or "L") to regain the Altitude Preselect
function.

SPZ-8400: The Altitude Preselect will automatically work off of the selected DADC.

PITOT-STATIC SYSTEM

Clogged Static Ports Cause Erratic Airspeed and Altitude Readouts

We recently had a GIV experience erratic airspeed and altitude readouts on both primary
flight displays (PFDs) during climbout. The aircraft returned to base (RTB) and made an
uneventful landing.
Gulfstream IV Notes 79
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The subsequent inspection found that the static ports were clogged with bugs or other
kinds of debris. The system was purged, and the aircraft was returned to service. There
was nothing else noteworthy about this event.

Another aircraft had a similar incident with the safety valve ambient line. We suggest that
on preflight you take an extra minute to look at the static ports/lines.
(GAC Breakfast Minutes – (01/20/98 )

ALTITUDE ALERTING SYSTEM

Tone will sound at:  ±250' deviation from assigned altitude
 1000' prior to level off altitude

ALTITUDE PRESELECT DISPLAY

A GIV aircraft had recently been through maintenance. Technicians noted that when they spun
the altitude preselect knob on the flight guidance panel (FGP) it would change on the primary
flight display (PFD), but it would not show anything but “9999” on the FGP.

When you turn the altitude preselect knob, you are actually turning a three-wire tach—input to
both digital air data computers (DADCs). If you are coupled to the no. 1 side, you are using the
no. 1 DADC. The no. 1 DADC puts that preselected altitude on the avionics standard
communication bus (ASCB), which transmits it to the symbol generators and the flight guidance
computers (FGCs). The information was getting from the FGP down to the DADC, which was
putting it on the bus, and the symbol generators were putting it on the PFD, and the altitude
changes could be seen on the PFDs.

What was wrong was that the FGC was not putting it on the FGP, because the displays in the
cockpit did not show a static air temperature SAT) or a true air speed (TAS) indication –they were
dashed out (----). The SAT and TAS indications displaying dashes show you do not have valid
true air temperature (TAT) input to the DADC. Without TAT into the DADC, it will not compute
SAT or TAS and without those the FGP cannot do the altitude preselect, resulting in it presenting
9999.

We found out that while the aircraft was in maintenance, someone had pulled the cheek panel
and disconnected the Rosemount probe. We suggest you always look at the other indications.
There is a lot of information available in the cockpit.
(GAC Breakfast Minutes – 7/7/98)

ENGINE SYNCH

MODES:

In FLCH climb/descent -- Engines synch to EPR's (does not enunciate)

In pitch hold or vert speed climb/descent -- LP/HP synch (as selected)
Gulfstream IV Notes 80
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To LP/HP synch engines in FLCH mode:

 Deselect A/T
 Engage LP or HP synch
 Manually set power levers to displayed power required (green carrot)

Go-Around Mode may be removed by hitting Go-Around button a second time

Useful if inadvertently hit during auto-throttle cruise

SPZ-8400
Incorporated on SN 1253 + subs (GIV SP).

New radio control unit was started with SN 1315.

Allows dispatch with only DU-5 inoperative as with the SPZ-8000.

ASC 345 – SPZ-8000 to SPZ-8400 conversion.

1,000 man-hours/$1,000,000 to accomplish

Represents a major change to baseline GIV wiring -- aircraft gutted.

FLIGHT DIRECTOR
SPEED SCHEDULES

 Takeoff speed schedule:

 Bugs on V2 until V2 is obtained, then the bug moves to V2 + 10.

 When flaps retracted, bug moves to 200 KTS
 When the FLCH mode is selected, the speed bug moves to 240 KTS

 Approach/landing speed schedule:

 Approaching the airport, the speed bug changes to 200 KTS.

 On lowering flaps 10, speed target reduces to 180 KTS
 On lowering flaps 20, speed target reduces to 160 KTS
 On lowering flaps to full down, Vref + 10
Gulfstream IV Notes 81
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SYNCHING SPEED BUG TO CURRENT A/C SPEED

To lock current indicated airspeed into the speed bug, push the A/S/Mach button on the
FGCP twice. Speed bug will slave to current airspeed.

OTHER AVIONICS EQUIPMENT

HONEYWELL RADAR
Three versions of Honeywell radar are currently being used: Primus 800
Primus 870
Primus 880

Leave radar in standby until needed

300% life increase by not using full time

During taxi, leave radar in standby until parked (instead of turning off)

PLACE RADAR CONTROLLERS IN STANDBY AFTER LANDING

An aircrew landed their GIV with both radar controllers in the Weather (WX) mode. The radar
automatically went to Forced Standby (FSBY) upon landing as designed. As they taxied the
aircraft onto their ramp, the copilot selected his radar controller to Standby (STBY). Shortly
afterwards, the pilot noticed that the radar was in the WX mode again and transmitting. This was
an unsafe condition for ground crews working close to the nose of the aircraft, and it prompted
the pilot to call Honeywell. We would like to point out the differences in Forced Standby operation
in the different radar systems.

System ControllerP/N Exits Forced Standby By

Primus 800 7006921-312 Any selection of EITHER MODE switch

Primus 870 7006921-413/-414 Any selection of BOTH MODE switches

7006921-415/-416 Any selection of EITHER MODE switch

Primus 880 7006921-815/-816 Push STAB button 4 times within 3 seconds

Forced Standby places a radar in a standby mode that prevents the radar from transmitting and,
therefore, exposing ground personnel to radiation. Aircrews should be familiar with the specific
operation of their aircraft’s system to prevent harm to ground personnel. The Gulfstream IV
Airplane Flight Manual calls for BOTH controllers to be placed to STBY after landing. Although
Honeywell addresses the situation this aircrew encountered in Honeywell’s Pilot’s Manual, they
will review the manual to ensure the present information is adequate.
(GAC Breakfast Minutes – (08/12/97 )
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GROUND PROXIMITY WARNING SYSTEM (GPWS)

Controlled flight into terrain (CFIT) is statistically 25 times more likely than a mid-air
collision.

New GPWS being developed that will have a look forward capability

Will feature a visual indication of the avoidance procedure similar to TCAS.

See the next section covering EGPWS.

ENHANCED GROUND PROXIMITY WARNING SYSTEM

(EGPWS)
Is an AlliedSignal product.

Reported to be very effective at terrain avoidance and situational awareness.

Uses a terrain model contained in a database along with GPS positional inputs to display
and warn of nearby high terrain.

Does not contain man-made structures in the terrain database.

AlliedSignal’s Enhanced Ground Proximity Warning System

Today’s technical update included a video about AlliedSignal’s Enhanced Ground Proximity
Warning System (GPWS). Randy was introduced to Enhanced GPWS a little over a year ago
when he had the opportunity to test fly it on a GIV trip to Asheville, North Carolina. Those of you
who have flown into Asheville are aware of the terrain encountered during approach. The flight
crew could easily maintain situational awareness of the terrain, relative to the approach.

“It is probably one of the most impressive safety features that has been added to an airplane in
some time. Its value is increased pilot situational awareness. When you fly this system, you have
a very graphic display of the terrain around you and where to maneuver to avoid the threat, both
vertically and laterally,” Randy said. The benefit we see in Enhanced GPWS is when you are
going into a strange airfield where the terrain is a consideration. Couple this with the approach
overlays and Gulfstream saw a safety feature that we want in our aircraft. Enhanced GPWS will
be standard equipment on the GV when it enters service, and will also be an option on the GIV
and GIV-SP aircraft.

We are including a portion of the video script in the following paragraphs.

Controlled Flight Into Terrain (CFIT) remains the single largest threat to the
world’s transport and corporate aircraft. To this challenge, AlliedSignal now
introduces a new level of technology, a new generation of GPWS -- the
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Enhanced GPWS. Using the AlliedSignal Mark V GPWS as a baseline,

Enhanced GPWS incorporates a worldwide terrain database, a runway database,
and aircraft position supplied by GPS and flight management systems already
onboard the aircraft. Together these enhancements provide substantial new
capability to reduce the possibility of CFIT.

Two new features of the Enhanced GPWS are the terrain clearance floor and the
terrain display system.

Terrain Clearance Floor -- The terrain clearance floor is designed to alert pilots to
a possible premature descent during non-precision approaches. Using runway
position data, a protective floor is constructed by Enhanced GPWS around the
airport. The terrain clearance floor begins roughly ½ mile from the runway and
climbs with respect to terrain at approximately 100 feet per mile until reaching
500 feet above ground level, some five nautical miles from the airport. The floor
maintains this 500-foot relationship with terrain until reaching 12 nautical miles
from the airport. The terrain clearance floor increases again at 100 feet per mile
until reaching 800 feet above ground level at 15 miles from the airport. The 800-
foot floor is then maintained to a distance of 25 nautical miles from the airport.
This construction provides alerts during long, low approaches, while avoiding any
unwanted alerts along a normal 3° descent flight path.

As an aircraft approaches the airport, it now has protection from premature

descents into terrain or the possibility of landing short of the runway. This
function is always enabled, regardless of aircraft configuration, around every
airport with hard-surfaced runways of 3,500 ft. or longer. Should the aircraft
penetrate the terrain clearance floor at any point, the GPWS red warning lamp
will illuminate and the voice alert “Too Low -- Terrain!” will be heard. For specific
airports with unusual terrain factors, the terrain clearance floor dimensions or
gradient can be modified to provide increased safety margins. Terrain Display --
Perhaps the biggest step toward the elimination of CFIT is being made with the
Enhanced GPWS terrain display. For the first time in commercial aviation, pilots
can now have a virtual look-ahead display in the cockpit to show any potential
threatening terrain.

Using a worldwide terrain database, aircraft altitude, and position information,

Enhanced GPWS displays a plan view of terrain ahead of the aircraft. Terrain
can be shown on existing EFIS map displays or on weather radar displays in
non-EFIS aircraft. Terrain is displayed relative to the aircraft altitude in three
distinct colors using a dot pattern of varying density:

• Light-density green dots indicate terrain 1,000-2,000 feet below the aircraft’s
current altitude.
• Medium-density green dots indicate terrain at a safe altitude below the aircraft,
down to 1,000 feet below.
• Medium-density yellow dots indicate terrain from approximately 500 feet below
the aircraft’s altitude, depending on phase of flight, up to 1,000 feet above the
aircraft.
• High-density yellow dots indicate terrain 1,000-2,000 feet above the aircraft.
• High-density red dots indicate terrain 2,000 feet or more above the aircraft’s
current altitude.

As an aircraft approaches significant terrain, Enhanced GPWS looks ahead and

provides alerts and warnings to the flight crew. At one minute from dangerous
terrain, the voice alert “Caution Terrain!” is heard twice and the threat is
displayed as a solid, bright yellow color. This alert will repeat if the threat is still
Gulfstream IV Notes 84
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present after 7 seconds. If no action is taken, at 30 seconds the voice warning

“Terrain, Terrain -- Pull Up! Pull Up!” is heard and the terrain threat is displayed
as a solid, bright red color.

In a normal flight profile, as an aircraft climbs to altitude, the terrain display

changes color and becomes less dense in appearance because the relative
altitude below the aircraft increases. Eventually the display becomes blank as all
terrain within range is more than 2,000 feet below the aircraft.

Conversely, as an aircraft descends toward an airport, terrain begins to show as

light-density green dots when it is within 2,000 feet of the aircraft. As the aircraft
gets lower, more and more terrain is displayed with increasing pattern density
and yellow or red colors indicating terrain near and above the aircraft altitude.
The distinct colors and patterns give the flight crew a tremendous new situational
awareness to instantly determine where terrain is above or below the aircraft. A
full 60 seconds from potential conflict with terrain, the areas that represent a
terrain threat change to be displayed as a solid color. A bright yellow area will
replace the dot pattern and a voice alert “Caution Terrain!” will be heard twice. If
no corrective action is taken, at the 30second point the terrain areas that
represent the most immediate threat will turn bright red and the voice warning
“Terrain, Terrain -- Pull Up!” will be heard. Simplicity and utility for pilots are
major advantages of the Enhanced GPWS and terrain display. Range capability
of the terrain display is pilot selectable from 10 to 320 nautical miles, depending
on the specific aircraft EFIS map or weather radar displays.

Depending on aircraft type, the pilot will be able to select either the weather radar
or the terrain display as desired throughout a flight. Should the terrain display be
de-selected when a terrain threat is encountered, the display can be configured
to pop up automatically, display the terrain threat, and give the voice alert
“Caution Terrain!”

The Enhanced GPWS terrain display will be fully integrated and prioritized with
other alert and warning functions on the aircraft such as storm warning, predicted
wind shear warnings, current GPWS warnings, and TCAS advisories. A
capability is also being developed to support presentation and alerting for
significant man-made obstacles. This is an important part of Enhanced GPWS.
An example might be an unusually tall radio tower that penetrates the limits of
the terrain clearance floor.

The video then showed a re-creation, by AlliedSignal’s flight test aircraft equipped with Enhanced
GPWS, of two incidents where aircraft were within seconds of a CFIT situation. In both re-
creations, Enhanced GPWS gave much longer warning times and greatly increased situational
awareness over the standard GPWS Mode II equipment.

AlliedSignal’s Enhanced GPWS is the most effective and advanced technology available to
reduce the threat of CFIT. Enhanced GPWS is now available for original installation or as a
replacement for the Mark V GPWS. In early 1997, Enhanced GPWS will be available as a direct
replacement for the Mark VII GPWS.

(GAC Breakfast Minutes – 10/15/96)

STCs Now Available for AlliedSignal’s Enhanced GPWS

Two GIV Supplemental Type Certificates (STCs) are now available for installation of
AlliedSignal’s Enhanced Ground Proximity Warning System (GPWS) with Windshear. STC
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ST01445AT-D is for aircraft with the SPZ-8000 Flight Management System (FMS). STC
ST01457AT-D is for aircraft with the SPZ-8400 FMS. Enhanced GPWS incorporates a worldwide
terrain database, a runway database, and aircraft position supplied by Global Positioning System
(GPS) and FMS equipment onboard the aircraft. Together these enhancements provide
substantial new capability to reduce the possibility of Controlled Flight Into Terrain (CFIT).
(GAC Breakfast Minutes – 09/16/97)

EGPWS Causes Erroneous Weather Radar Annunciation

Some GIV aircraft are equipped with the enhanced ground proximity warning system (EGPWS).
We have had a few reports that involve a flight crew member turning on the weather radar, then
getting the green icon on the NAV display; then turning the EGPWS on; then turning the weather
radar off. When this scenario happens, the green icon stays illuminated on the NAV display. This
is a known software problem that Honeywell is addressing.

Gulfstream will notify operators following Honeywell’s resolution of this problem.

(GAC Breakfast Minutes – (01/27/98 )

How to Prevent Erroneous Weather Radar Fail Message on Aircraft with EGPWS

On GIV aircraft equipped with an Enhanced Ground Proximity Warning System (EGPWS), there
is a known erroneous message that occurs during the operation of the Honeywell weather radar.

If the weather radar is operating and the on-side display controller’s map menu item is “selected”
or “boxed” in the “GPWS” and then unboxed, an erroneous weather radar “Fail” message will
appear on both navigation (NAV) displays, tubes 2 and 5. The “Fail” message will remain
illuminated until both weather radar controllers are cycled “off,” and then back “on” to the desired
radar-operating mode. This will also happen if the automatic “pop-up” function triggers the
EGPWS. The radar is still working, but it is a little confused with all the extra screen painting.

By using the following work around procedure, you can prevent the nuisance messages until our
engineers correct the problem. Before deselecting (unboxing) on a display controller’s map menu,
ensure that the on-side weather radar controller is switched to STBY (standby). After deselecting
the “GPWS,” the weather radar may be selected to any desired mode. This keeps you from
cycling the radar off, then back on, and having to wait for the radar time out sequence, before the
radar starts working again.

We have many of these installations out in the field and this is the first we have heard of this. If
you have experienced an incident similar to this in your aircraft, please contact Technical
Operations at 912-965-4808 (phone) or 912-965-4184 (fax).
(GAC Breakfast Minutes – 7/28/98)

VHF COMMUNICATIONS RADIOS

RADIO TUNING UNITS

Radio Tuning Unit (RTU) Configuration Errors

A GIV, which had just gone into operation, experienced during instrument landing system (ILS)
approaches the flight management system (FMS) control display unit (CDU) would not tune the
Gulfstream IV Notes 86
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RTUs. The frequency would be entered into the CDU and would display on the RTU, but would
stay there for a few seconds and then revert to the previous frequency.

When first reported, the technician indicated that the event happened only on one side. When
rechecked for more information, the problem was found to occur on both CDUs and both RTUs.
To get our facts together we talked to Honeywell, who indicated they had seen a problem similar
to this one before that had to do with the configuration set-up with the RTUs.

On the RTU, if you simultaneously depress the top two buttons on each side and the lower right
button, the systems configuration page will display. This will show the set up for the number one
and the number two RTUs.

If you look at line two, it shows CONFIGURATION CODES; under that are codes for RTU1 and
RTU2. On the GV RTU 14 digits will display. These are hexadecimal and represent the number of
VHF comms, the VHF comm frequencies (extended or short-range), DME, ADFs, FMS, and
every navigational aide installed. If there is a mismatch between the two codes, a configuration
error will display on your aircraft’s RTU. The display indicates that the two RTUs are not in sync.
One catch, and what was the case with this event, is that if a wrong code is entered in both
RTUs, or if you crossload the wrong code, you will not get the configuration error (because the
two codes match). If the codes are not appropriate for your particular aircraft, but are in
agreement with each other, then you will not get a configuration error.

With the field service representative and operator on site, we relayed to them the procedures for
accessing the configuration code. They found that both codes were the same, but digit 12 was a
five (indicating per the set-up manual a Collins/GNS/GNX-type FMS). The proper twelfth digit of
the code for a GV (indicating a Honeywell FMS) should be a three.

Changing and Restoring RTU Codes

You can use several methods to update the code. In this situation, the codes had to be manually
set up using the MANUAL CONFIG SETUP and the SCROLL WITH TUNE KNOBS from the
system config page. If you are installing an RTU and have entered the wrong code, you can
restore the last configuration. If you are putting in a unit just received from supply, and the other
unit is already set up, you can use a crossload. You may crossload RTU1 to RTU2 or vice versa.
Note that lines 5 and 6 of the system configuration display show UPDATE RTU1 to RTU2
(RTU1®RTU2) or RTU2 to RTU1 (RTU1¬RTU2).

We suggest that if your aircraft has RTUs or they are installed later on, that once they are
configured, you write down your configuration codes and put them where pilots and maintenance
personnel can reference them when needed. This aircraft had only been in operation for two
weeks. When it left the factory everything worked normally, but someone changed the code. To
ensure this does not happen to you, have the proper code available for reference.
(GAC Breakfast Minutes – 7/7/98)
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FM Immunity Program Tightens VHF Nav/Comm Frequency Selection Standards

The Problem - Approximately 20 years ago, pilots began noticing that they could hear FM
broadcasts over the Morse code identifiers for ILS approaches at European airports. The signal
from high-powered FM stations near airports was bleeding into the ILS frequency. This can
happen since the top of the FM radio station frequency band butts the bottom of the aeronautical
VHF band. As FM broadcasters increased the station power output, the problem became more
prevalent. This has not been a problem in the US, since the Federal Communications
Commission will not allow higher power FM transmitters to be built close enough to an airport to
cause interference.

The Solution - The solution was to tighten the frequency selection standards of VHF aircraft nav/
comm receivers. ICAO (International Civil Aviation an Organization) developed the tighter
specifications but it is up to the individual European countries to adopt the standards and phase
them in. That is in process today.

The Schedule - Most European countries involved are phasing in the tighter standards in
navigation equipment first and in the communication equipment at a later date. The reasoning
behind this is that the navigation frequencies are closer to the FM radio band and suffer the
highest interference. The communications equipment is phased in at a later date so other
upgrades for that band (i.e., “triple-split frequencies”) can also be addressed in conjunction with
the tighter selection standards.

The deadlines for FM Immunity (in European countries) can be summarized as follows: • New
Equipment - All new VHF navigation and communications equipment in Europe was required to
be in FM immunity compliance by January 1, 1996.

Operators of non-ICAO nation aircraft should ensure that the proper service bulletins are
incorporated on equipment installed in 1995 or 1996.

• Existing VHF Navigation Systems - Most European countries will require existing VHF
navigation systems to be in FM immunity compliance by January 1, 1998.

• Existing VHF Communication Systems - Most European countries will require existing VHF
communication systems to be in FM immunity compliance by January 1, 1999

Marker Beacon/VHF Nav/VHF Comm: (108.0 - 151.975)

FM Radio Broadcasts: (88.0 - 108.0)

VHF Band (Very High Freq.): 30 - 300 MHz

• Mandatory for All Operators - By January 1, 2001, all VHF navigation and communication
systems operating in all European countries must have the tighter frequency selection standards.

The Fixes - The following list includes the typical navigation and communications receivers for
Gulfstream aircraft. Collins Collins Navigation Receivers Service Bulletin
VIR-30 S/B 20
VIR-31 S/B 14
VIR-32 S/B 23
VIR-432 S/B 9
VIR-433 All units comply VHF Collins Comm Transceivers Service Bulletin
VHF-20 S/B 13
VHF-21 S/B 21
Gulfstream IV Notes 88
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VHF-22 S/B 21
VHF-422 S/B 12

If your equipment does not meet the latest modification standard, additional bulletins may be
required to bring the equipment up to the correct service bulletin level before adding the FM
immunity modification.

If this list does not include a VHF receiver that is on your aircraft, or if you need the compliance
schedule for a specific European country, contact the Avionics Group in Technical Services at
912-965-3241 (phone) or 912-965-4184 (fax).

(GAC Breakfast Minutes – 04/22/97)

Closing Comments
Q - Our experience with Gables has found them to be slow to incorporate software changes. How
will this impact the FM immunity program?

A - The GIV Gables control heads will not be affected by the FM immunity program. However,
they will be a part of the new 8.33 Khz spacing (triple-channel split) requirements. The control
head will conform to the change by dropping the 100s digit and moving all other digits one space
to the left (121.50 will become 21.500). A software change will also be required.

(GAC Breakfast Minutes – 04/22/97)

8.33 KHZ CHANNEL SPACING ISSUES

Delay Announced in Implementation of 8.33 kHz Channel Spacing

Deadline Delay Announced June 6, 1998—The EUROCONTROL ATM/CNS Consultation

Group (ACG) has unanimously concluded that the original Jan. 1, 1999 deadline for the
implementation of 8.33 kHz channel spacing in the ICAO EUR region was no longer maintainable
due to the low percentage of aircraft projected to be 8.33 kHz capable on that date. This
conclusion was reached after assessing the retrofit information provided by aircraft operators,
directly to EUROCONTROL and/or via The International Air Transport Association (IATA) and
ATA.

The conclusion was fully supported by the aircraft operators and representatives, who, however,
stressed that this low rate of equipage was not due to the aircraft operators reluctance to meet
the requirement. Rather, in most cases, aircraft operators saw their carefully set up plans being
invalidated by circumstances quite beyond their control (non-availability of hardware, certification
difficulties, unexpected EMI, etc.). The ACG has decided that a new deadline will be determined
at their next meeting in the second week of July 1998.

For details on the delay of the 8.33 kHz spacing implementation, visit the following section of the
IATA web site: http://www.iata.org/8.33/news1.htm. The site provides a detailed summary of the
ACG meeting findings, some “What happens if…” scenarios, and contacts (one for how to obtain
a copy of The 8.33 kHz Implementation Plan and/or The 8.33 kHz User Guide).

Background—The “Plan for the 8.33 kHz Channel Spacing Implementation in Europe" was
developed by EUROCONTROL. Endorsed in November 1996 by The European Air Navigation
Planning Group (EANPG), the plan stated that the carriage and operation of 8.33 kHz channel
spacing capable radio communication equipment was to become mandatory in the International
Civil Aviation Organization (ICAO) EUR Region on 1 January 1999 for flights above FL245
generally, and for flights above FL195 over France.
Gulfstream IV Notes 89
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States that will initially implement 8.33 kHz channel spacing operations are: Austria, Belgium,
France, Germany, Luxembourg, the Netherlands, Switzerland, and the United Kingdom.

The United States has no formal plan for implementation at this time and is unlikely to require
compliance in the foreseeable future.

This subject will be addressed at a Customer Breakfast meeting and Breakfast Minutes following
the announcement of the new implementation deadline.
(GAC Breakfast Minutes – 6/16/98)

Monitor the International Air Transport Association (IATA) Web site for news on the 8.33 spacing
issue. Go to www.iata.org/8.33 (ref. 6/16/98 Breakfast Minutes).
(GAC Breakfast Minutes – 7/28/98)

Gables Modifications Forthcoming for VHF/NAV Bus Timing Improvements

Gables modifications to improve bus timing between the VHF/NAV control heads and their
respective transceivers are being finalized. Earliest availability for production and service
incorporation is estimated at 3rd Qtr. 1997.

VHF - Gables has proposed a VHF control head software mod to correct an intermittent display of
the 121.50 MHz frequency. During a power interrupt or when the 429 data bus processor resets
after self-test (or from EMI), the control head briefly displays “121.50.” The transceiver transmits a
valid 121.50 to the control head during the wake-up period after the unit is turned on. Currently,
the control head accepts and displays a valid 121.50. When the transceiver catches up to the
control head, the control head displays the previous valid frequency. The proposed software mod
will let the unit ignore the first valid frequency for 3.5 seconds and eliminate intermittent operation.

Nav - Following a power interrupt, with the system in the remote tune enable mode, the Nav
control head displays “F---,” indicating no data is being received. During the wake-up period, the
transceiver sends “100-NCD” - a burst tune stating no control data. The control head bursts the
last valid frequency. The transceiver takes too long to accept the valid frequency from the control
head and to echo it back to the control head.
The proposed software modification will allow the transceiver sufficient time to echo the last valid
frequency sent by the NAV control head. GIV - Gables Control Head Modified for 8.33 kHz
Spacing Awaits FAA Approval Gulfstream has reviewed a Gables control head that will conform
to the upcoming European 8.33 kHz VHF communication frequency spacing requirement. The
proposed unit drops the 100s digit and moves all other digits one space to the left, e.g., 121.50
becomes 21.500.
A software change will also be required. This proposed modification is awaiting FAA approval.
ICAO (International Civil Aviation Organization) has granted an extension until January 1, 1999,
for mandatory implementation of the 8.33 KHz spacing.
(Editor’s Note: An article on the 8.33 kHz spacing is forthcoming in Service News 97-2.)

(GAC Breakfast Minutes – 06/17/97)

Gables Control Head Being Modified for the 8.33kHz Spacing

The new Gables control head is similar in appearance to the old control head, with the exception
of the toggle switch. The toggle switch, which used to select 121.5, now toggles between the
standard 25kHz spacing to the 8.33kHz spacing. Digits move one space left for 8.33kHz tuning.
Anticipated approval is first quarter of 1998.

It is important to reiterate that if you want to do remote tuning with the flight management system
(FMS) to this unit, you need the NZ-2000 5.0 mod.
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(GAC Breakfast Minutes – (01/20/98 )

8.33 kHz Control Head Spacing Upgrade

Charlie said that quite a few calls are coming in about the GIV Gables control head requirements
for 8.33 kHz spacing, the new European VHF communication frequency standard that is
scheduled to become effective January 1, 1999.

The new Gables control head is similar in appearance to the old control head, with the exception
of the toggle switch. The switch, which used to select 121.5 kHz, now toggles between the
standard 25 kHz spacing and the 8.33 kHz spacing. Digits move one space left for 8.33 kHz
tuning.
(GAC Breakfast Minutes – 5/19/98)
8.33 kHz Tuning Via the FMS CDU

In order to tune 8.33 KHz via the FMS CDU, an FMS software modification is required. NZ5.0,
and later software versions, for the NZ-2000/IC-800 platforms, will support 8.33 KHz tuning. Older
hardware platforms (NZ-9XX/8XX/6XX) will not be updated to support this functionality.
(Honeywell FMS Technical Newsletter – September 1998)

HF COMMUNICATIONS RADIOS

OVERCOMING UNCERTAINTY OF HIGH FREQUENCY RADIO

CAPABILITIES

This year has been a particularly bad year for high frequency (HF) radios. A combination of
sunspot activity, meteor showers, El Nino, and just generally bad atmospheric conditions have
caused some operators to be concerned about their overseas HF operational capabilities.

Following are a few HF radio operating tips:

· Run HF radios periodically in your area; check both radios
· Call some operators in your area and inquire if they are having any problems
· Call Technical Operations. You or your Technical Operations contact can call Collins
Radio to inquire if the current conditions are good or bad for HF transmission.

Before you doubt your HF radio’s capability or turn to measures like swapping out boxes,
Gulfstream can provide you with several avenues to explore. One is to dial up WWV
(www.ubr.com/clocks/nist/wwv/wwv.html) which broadcasts on 2.5, 5, 10, 15, and 20 MHz to see
what the best frequency is for that day. (Ref. 4/16/96 Breakfast Minutes.)
(GAC Breakfast Minutes – 7/28/98)

TRANSPONDERS

Excessive Ground Wire Lengths Cause Transponder and Comm Irregularities

Some GIV aircraft have experienced problems with the transponders dropping off standby and
changing frequencies. Also, some comm radios were dropping off and changing frequency to
121.5 MHz. A GIV aircraft was analyzed by Collins and Gulfstream engineering. They found the
ground points were good; however, the ground wire lengths were too long. This extra wiring acts
Gulfstream IV Notes 91
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like an antenna and picks up “noise.” The best way to attenuate the EMI is to shorten the wiring.
An acceptable length is 6 inches with an allowance up to about 18 inches.

The grounds were localized and the aircraft has been back in service for about a month without
further transponder or comm problems. We have modified other aircraft and no repeat incidence
has been reported. Production engineering is evaluating the modification to see where changes
may be needed.

(GAC Breakfast Minutes – 03/11/97)

Collins Service Bulletin

Modify TDR-94D Squitter Test

In the March 11, 1997, Breakfast Minutes, we reported that some GIV aircraft were experiencing
problems with the transponders dropping off standby and changing frequencies. Ground wire
lengths were found to be too long. The grounds were localized to correct the condition.

Rockwell/Collins recently notified us of an aircraft operating at the Minneapolis-St. Paul

(Minnesota) Airport reporting a similar problem after correcting and localizing the aircraft grounds.
The selected TDR-94D transponder would go to standby mode, and the ATC control altitude
display would become dashed. Analysis determined the TDR-94D transponder squitter test had a
small potential to fail in a dynamic interrogation environment. The airport’s new Precision Runway
Monitor (PRM) radar, Mode-S SSR (Secondary Surveillance Radar) interrogation, and heavy
TCAS traffic provided such an environment. With all the interrogation rate information, the
transponder could not keep up.
When the squitter test failed, the TDR-94D set its output data to the Fail/Warn state as directed
by Mode-S requirements. However, the TDR-94D also set the control word to the Standby state.
When the Gables control heads received the standby condition, they issued a Standby command
to the transponders, which kept them in standby.
Current Events
A forthcoming software solution adds a modification to increase tolerance for interrogation rates
of the TDR-94D squitter test. If the squitter test fails, the TDR-94D will not set the control word to
Standby. When the Rockwell/Collins service bulletin is available, it can be installed when
practical.
(GAC Breakfast Minutes – 06/17/97)

TCAS SYSTEM
GIV TCAS is heat sensitive -- needs good cooling

ANGLE OF ATTACK SYSTEM (AOA)

If an AOA sensor ices up -- pull out the affected CB on the CPO.

Can set off the Shaker when frozen.

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HUD

HUD/EVS Increases Landing Safety

The following information about Head Up Display is taken from a recent Gulfstream press
release.

A new Head Up Display (HUD) with Enhanced Vision Systems (EVS) is being readied as an
option for the Gulfstream IV-SP and Gulfstream V aircraft. The HUD will display the runway
image for pilots flying in bad weather - even when conditions such as fog, smoke, or haze limit
visibility. What the pilots actually will be viewing is the Honeywell/GEC Marconi HUD 2020, which
incorporates a transparent screen or “combiner” to display computerized optics in a picture format
that outlines the runway, and provides a glide path, center line, altitude, air speed, aircraft flight
path, and flight director - all that is needed to land the plane.

The HUD provides a “conformal picture,” meaning the images on the combining glass relate to
the real world. It allows lower landing minimums and is particularly useful as pilots make the
transition from an instrument approach to visual conditions. It also provides instant recognition of
windshear conditions and guidance to optimum recovery.

“The advantage is that the image the pilot sees overlies the landing runway so he sees a scene
that is very much like the visual landing scene,” said Bob Morris, HUD/EVS Program Manager at
Gulfstream. “The pilot’s ability to generate a visual glide path and continually assess his position
relative to the runway is a tremendous improvement in safety when approaching some airports at
night and in low visibility situations.”

When combined with an Enhanced Vision Sensor such as an infra red detector, the HUD can
significantly lower landing minimums at many airports while improving the pilot’s ability to “see”
the outside scene in all weather and darkness conditions.

Certification for Category II operations is expected later this year along with the demonstration of
EVS capability. Certification of the Enhanced Vision capability is expected in 1997.

"The Gulfstream IV-SP will be the first business aircraft to incorporate Enhanced Vision
technology, keeping it on the leading edge of technology," Morris said. “This is a pace-setting
effort by us,” Morris said, noting the option is also being offered on the new Gulfstream V, the
world’s first ultra-long-range, large-cabin business jet. Nearly half of the Gulfstream V customers
have indicated they want the HUD and EVS capability. They want the ability to safely lower the
landing minimums at the airports they frequently use. EVS incorporates sensors so pilots can
gauge the runway environment on a HUD before actually seeing it. Infra red and millimeter wave
radar sensors are being tested by several sensor manufacturers.

Gulfstream has been evaluating EVS sensor performance and has selected Kollsman, Inc., of
Merrimack, New Hampshire, to produce an infra red system for the Gulfstream IV-SP and
Gulfstream V, according to Morris. A prototype system could be operating later this year.

“About 65 flight tests of the HUD involving more than 40 pilots have been conducted already, and
we’re getting very precise landing guidance, including guidance during the flare,” Morris said.
Gulfstream IV Notes 93
Revision 2-98 Avionics

Unique to Honeywell’s system for the GIV-SP and GV is a pitch limit indicator that gives pilots
good low- speed awareness when they are approaching a stall situation. It also provides valuable
information for windshear recovery guidance and enhanced altitude awareness cues to alert
pilots.
(GAC Service News -- July - August - September 1996)

EFFECT OF YEAR 2000 TRANSITION ON HONEYWELL PRODUCTS

There is continued interest in the effect of the year 2000 on various computer systems. As a
result, we are providing here in the Breakfast Minutes the answer to the following question asked
in the 1997 Workshop GIV session concerning Honeywell products.

Question: What is the effect of the transition at 1 January 2000 on the operation of existing
Honeywell products?

Answer: LASEREF, GNSSU, and Air Data Computers will see no effect of the year 2000.

For reference, the only Honeywell product that will exhibit problems with dates is the 2-channel
GPSSU HG2021AB01. This will not handle the GPS week rollover. The GPS week rollover is in
1999 and has nothing to do with the year 2000. The week rollover is because of the GPS week
counter being 1024 weeks from the beginning of GPS (around 1980). Newer GPS units account
for this and will set another bit internally to indicate that we will be in the second 1024 week
period.

The following text is from a Honeywell document which addresses the effect of the year 2000
transition on their existing FMS products.

“The FMS Product Team has investigated the effect of the transition at 1 Jan 2000 on the
operation of our existing products. Following are the results of this investigation.

“In general, the flight management hardware and software will operate through and beyond the
year 2000 transition without interruption. All core functionality, including flight planning,
navigation, and performance, will continue to operate as normal.

“The only detrimental effect of the transition is related to the navigation database. The database
cycle which spans the transition (30 Dec 99 to 26 Jan 00) will be displayed on the CDU IDENT
page as 30 DEC 99 to 26 JAN **. The software currently adds 28 days to the cycle’s start date to
compute the cycle’s ending date. Unfortunately, it does not account for year 99, incorrectly
computing 100, which cannot be displayed in the field provided.

“In addition, the FMS will not automatically select that cycle during its effective period. The result
of this is that, from 30 Dec 99 to 26 Jan 00, both Nav database cycles will be displayed in amber,
and the pilot will be required to manually select the correct cycle.

“We plan to include a software change in all future FMS versions (NZ 5.0 +) to correct this
problem. In addition, all software mods released to previously certified versions will include this
correction. We do not plan to provide any software mods specifically for this problem. As the year
2000 transition approaches, we will determine which FMS versions continue to contain the bug.
At that time, we will send letters to the customers who will be affected describing the problem and
its work-around.”
(GAC Breakfast Minutes – 10/14/97)

Q - What is Gulfstream doing to ensure the Gulfstream fleet does not suffer from any Year 2000
(Y2K) related computer failures?
Gulfstream IV Notes 94
Revision 2-98 Avionics

A - Gulfstream has a dedicated team working this issue. We started in 1994 with our internal
Information Technology (IT) hardware and software data systems. About the middle of 1997, we
began looking at the aircraft systems for GIV and GV production aircraft. Another group is now
looking at post-production equipment installed by Gulfstream at our service or completion
facilities.

We have issued letters to all the authorized facilities in our support network, asking them what
steps they have taken to be in Y2K compliance. We will meet with these facilities on June 5,
following the 1998 Gulfstream Workshop.

We have communicated to around 2,400 suppliers about Y2K compliance. The ultimate objective
is to have satisfaction in our minds that the suppliers’ products are not susceptible to any Y2K
shortcomings nor are there inabilities to support Gulfstream production and in-service aircraft.

Gulfstream will be issuing a Maintenance and Operations Letter this week detailing our efforts.
We will also have a special Y2K presentation at Workshop.
(GAC Breakfast Minutes – 4/7/98)
Gulfstream IV Notes 95
Revision 2-98 Avionics

GIV HIGH REMOVAL COMPONENTS

Gulfstream IV Top 20 Removal Components as of July, 1998

As of July 1998

1000 Hr.
12 MONTH Removal
RANK NAME REMOVALS Rate

1 Display Unit........................................................211..................1.04
2 WING / TAIL STROBE LIGHT...................................161...................0.99
3 IRU / EMERGENCY BATTERY................................152...................1.87
4 RADAR RCVR/XMIT/ANT.........................................106...................0.67
5 CONTROL DISPLAY UNIT.........................................86...................0.42

6 INERTIAL REFERENCE UNIT....................................85...................0.42

7 DISPLAY CONTROLLER...........................................84...................0.41
8 VSCF CONVERTER...................................................82...................0.40
9 MAIN / BAGGAGE DOOR SEAL CHECK VALVE......81...................0.50
10 STANDBY ALTIMETER..............................................78...................0.48

11 AIR DATA COMPUTER..............................................78...................0.38

12 DATA ACQUISITION UNIT.........................................76...................0.37
13 FLIGHT GUIDANCE COMPUTER..............................73...................0.36
14 FLIGHT GUIDANCE PANEL.......................................70...................0.35
15 PERFORMANCE COMPUTER...................................68...................0.34

16 ATC TRANSPONDER................................................64...................0.39
17 VHF TRANSCEIVER..................................................62...................0.44
18 VSCF ALTERNATOR.................................................60...................0.30
19 APU INLET DOOR ACTUATOR.................................59...................0.36
20 T/R SECONDARY LOCK ACTUATOR.......................59...................0.36
(Taken from Gulfstream Web Site)

GIV — Overview of Dispatch Critical Component List

Gulfstream Aircraft Services developed the GIV/V Dispatch Critical Component Lists
last year to catalog operator-identified components that either caused a missed mission or
(based on the operator’s perception) had a high probability of affecting the outcome of a
mission. We did not consider the Master Minimum Equipment Lists (MMELs) as criteria
for the list selection. Reports sent in by operators and field service representatives are
collected by Gulfstream Information Services personnel, who compile the information
into a daily Aircraft Status Report. For the Dispatch Critical Component Lists, we looked
at Aircraft Status Reports spanning a 12-18 month period to identify which components
had affected a mission.

The GIV Dispatch Critical Component List total is 18. With each component we are
working with the component supplier to look for potential opportunities for
Gulfstream IV Notes 96
Revision 2-98 Avionics

improvements to reduce the number of missed/affected missions which are being

reported from the field. These improvements may come through training, troubleshooting
techniques, manuals, etc.

The lists are fairly dynamic in that when we see improvement, acknowledged through
reports from the field, we revise the list. The Gulfstream management team reviews the
lists monthly to ensure we are maintaining the correct focus and provide us assistance
when we require it.

Gulfstream is putting together the GI, GII, and GIII Dispatch Critical Component Lists. On
completion we will post these lists on the Gulfstream Web site (www.gulfstreamaircraft.com), within
the Customer Services area, in aircraft-specific areas, as we have done with the GIV and GV Dispatch
Critical Component Lists.

The GIV Dispatch Critical Components are:

GIV Component: Component Supplier:

VSCF Alternator AlliedSignal
Brake-By-Wire Brake ECU Aircraft Braking Systems
Cabin Pressure Safety Valve AlliedSignal
VSCF Converter AlliedSignal
Digital Air Data Computer (DADC) Honeywell
Flap Actuator Moog
Flap Follow-up Switch Eaton/Aerospace Controls Division
NWS ECU Messier Dowty
NWS Feedback Manifold Messier Dowty
NWS Servo Valve Manifold Assembly Messier Dowty
NWS Shutoff Valve Pneudraulics
Outflow Valve AlliedSignal
Cabin Pressure Transducer AlliedSignal
Power Distribution Box AlliedSignal
T/R Actuator Northrop Grumman
T/R Secondary Lock Actuator Northrop Grumman
Weather Radar Honeywell (P-870)
Windshield PPG
(GAC Breakfast Minutes – 7/4/98)

JAA LEAFLET HAS BASIC RNAV (B-RNAV) GUIDANCE

Gulfstream IV Notes 97
Revision 2-98 Avionics

With the release of the Joint Aviation Authority (JAA) Temporary Guidance Leaflet No. 2 revision
1, an operator asked Gulfstream whether the production GIV still met basic area navigation
(RNAV) requirements for Europe. Besides providing guidance material for airworthiness approval
and operational criteria for basic RNAV in European airspace, the JAA document also contains
guidance material for using stand-alone Global Positioning System (GPS) equipment for these
operations. The document’s reference to GPS equipment that is not a standard production
installation may have caused a few operators to think that it may now be a requirement. The JAA
leaflet considers existing airworthiness approval standards as providing acceptable means of
compliance. The following FAA Advisory Circulars are listed within the related navigation
documents and are acceptable for basic RNAV operations: AC 90-45A, AC 20-130, AC 20-138,
and AC 25-15. The GIV AFM notes, which appear on page 5-17 for the SPZ-8000 FMS and on
page 5-24K for the SPZ-8400 FMS, state: “Provided the Flight Management System (FMS) is
receiving suitable navigation information from at least one (1) VHF Omni Range/Distance
Measuring Equipment (VOR/DME) or two (2) DMEs, it is approved as an area navigation system
for enroute, terminal, and approach operations in accordance with FAA Advisory Circular No. 20-
130.” As described in the GIV AFM note, the GIV production aircraft comply with basic
requirements and no further documentation is required. Similar wording will be added to the GV
AFM for basic RNAV, and both the GIV AFM and GV AFM will have wording added to address
using GPS.
(GAC Breakfast Minutes – 09/23/97)
Gulfstream IV Notes 98
Revision 2-98 Avionics
Gulfstream IV Notes 1
Revision 2-98 Miscellaneous Systems

17. MISCELLANEOUS SYSTEMS

MAIN ENTRY DOOR
DOOR CLOSING

On 1156 + Subs -- The door can be closed using the External Door Closing Switch
without first activating the External Battery Switch.

If used in this manner, only battery #2 is used, preserving the capacity of battery #1.

If used after activating the External Battery Switch, both main batteries are used.

DOOR RETRACTION FAILURE

If the Main Entry Door fails to retract it may be a switch or an electrical problem. If this
is the problem, the door retraction mechanism can be activated by a mechanical valve just
aft of the door near the Brake Control System (BCS) box.

1. Remove the access panel covering that area.

2. Turn the valve counter-clockwise.
3. Turn on the Auxiliary Pump.
4. When door has stopped, lock the door using the normal procedure.
5. Turn the Auxiliary Pump off.
6. Close the valve (clockwise turns).

Note: If the control valve is not returned to the closed position (fully clockwise), the
door, when unlocked, will fall partially open and then stop due to a hydraulic lock. If this
occurs, return the valve to the fully closed position and the door will continue to settle
open normally.
Gulfstream IV Notes 2
Revision 2-98 Miscellaneous Systems

WINDSHIELD CARE

Windshield and Cabin Window Care & Cleaning

Dave updated the Breakfast audience on the new cabin windows and cockpit windshields being
installed on the GV, compared these with the older model GII/III/IV windows, and gave
maintenance considerations to take for each a/c model.

GIV Windshields

The original GII, GIII, GIV glass windshields have no exterior coating for rain repellent. Some
after-market products have been made available, and PPG recognizes Rain Away® as an
effective product for rain repellent on these earlier windshields.

Recommended cleaning of the older windshields is accomplished using a 50/50 mix of isopropyl
alcohol and water. We have received numerous questions lately concerning use of Methyl Ethyl
Ketone (MEK) on the early aircraft (GII/III/IV) windows; we do not recommend this product.

You should exercise caution when working around GI/GII/GIII/GIV glass windshields; if they get
scratched, cracked, or nicked there is no field repair available for them.

Later GIV (S/N 1320 and sub) and All GV Windshields (1159SCB3102 -11, -12)

The windshields used on the later GIVs and all GVs, which are also the preferred spares and
replacement for GIII and GIV aircraft, have incorporated some significant changes. The most
notable change is the weight reduction—of approximately 8 pounds. Another change is the rain
repellent coating, SurfaceSeal®, which is factory-applied (by PPG).

SurfaceSeal is a thin coating applied to the exterior surface to enhance rain shedding
characteristics. It is imperative that you use extreme caution when working around these
windows, as the SurfaceSeal can be scratched and its effectiveness compromised. Field repairs
are available to reapply the SurfaceSeal. The repair takes up to nine hours to accomplish, and
requires a kit that contains all required materials, including the seal solution and a heat blanket.
The kit is available through Gulfstream or PPG. Along with the nine-hour standard repair kit, a
one-hour repair kit is available for instances where flight schedules dictate a quicker turnaround.

Cleaning of these windows is accomplished using a 50/50 mix of isopropyl alcohol and water.
Again, Gulfstream does not recommend using MEK.

GII/III/IV Cabin Window Care and Cleaning

Cabin windows used on the GII, GIII, and GIV aircraft have some special considerations when it
comes to care and cleaning. The assemblies have no external coatings applied and should be
cleaned using a mild detergent or a plastic polishing compound such as Novus® 1 or 2 plastic
polish, if minor scratches—to 0.003 inch deep—are present.

Each aircraft-specific maintenance manual (MM) provides field repairs for surface scratches up to
0.020 inch. The appropriate MM also has repairs for edge defects or chips.
(GAC Breakfast Minutes – 5/19/98)
Gulfstream IV Notes 1
Revision 2-98 Performance

18. PERFORMANCE
INITIAL FLIGHT PLANNING
Initial flight time, fuel burn and maximum initial altitude can be derived from the Twin
Engine Flight Planning chart 1-7 found in the GIV Cruise Control Manual.

PERFORMANCE LOSS WITH ENGINE LOSS

With the loss of one of two engines 50% of total power is lost – but 80% of aircraft
performance is lost.

For a 60,000# GIV, a twin engine 20% climb gradient would be reduced to a 4% climb
gradient with an engine loss.

TAKEOFF CONSIDERATIONS
V1 SELECTION CRITERIA

The FMS selects max V1 when not runway limited and moves towards a balanced field
V1 as runway length becomes critical.

V1 Min (80% of VR) -- For slippery runways set V1 to minimum (Allows more stopping
distance)

Pro's:  Shortest accelerate-stop distance

 Best for use with contaminated runways (degraded stopping power).

Con's:  Bad for obstacle clearance

 May not be able to reach VR within available runway after an engine
failure with retarding slush contamination.

 V1 Min may be greater than 80% VR as restricted by V1 MCG .

V1 Max (100% VR) -- For obstacle clearance set V1 to maximum (allows more climb
distance to obstacle from the rotation point). This is used as the default setting by
Honeywell.

Pro's:  Maximum time to abort takeoff (with long runways, plenty of stop
distance).
 Shortest accelerate-go (takeoff) distance.
 Best obstacle clearance (single engine climb out).
Gulfstream IV Notes 2
Revision 2-98 Performance

Con's:  Bad for V1 aborts -- higher stopping speed, longer stopping distance

Balanced Field V1 -- Accelerate-go distance = accelerate-stop distance.

Pro's:  Allows the shortest runway requirement.

Con's:  Not optimized for either stop, go or obstacle clearance.

 May not be available due to gross weight or obstacles.

Balanced Field V1 Rule of Thumb – Reduce V1MAX by 3% or 3-5 knots.

(V1 BFL = 0.97 x V1 MAX )

V1MCG – The minimum speed at which you can lose an engine at T/O power and maintain
directional control by rudder alone.

TAKEOFF COMPUTATIONS

Accelerate-Stop Accelerate-Go

Stopway Clearway
 500' wide to max distance of 2000'
 Overrun* that will support the  Hard to find availability
weight of the A/C.  Located on Pt 135 airport data
 Located on Jepp Chart  Must be under the control of the airport
 Can use all available  Can't use water body unless under airport
control

Slope Slope
Winds Winds
Anti-Ice Anti-Ice
Anti-Skid
Ground Spoilers

* Note: "Overrun" when used on civil fields (non-military) may only refer to a clearway
-- might not bear A/C weight. May not use even as Clearway since the Clearway must be
500' wide and there is no guarantee that the 500' width exists.

International fields often list TODA & TORA

TODA -- Take Off Distance Available (Runway + usable clearway)

TORA -- Take Off Runway Available (Runway + usable stopway)
Gulfstream IV Notes 3
Revision 2-98 Performance

TIRE SPEED LIMITATIONS

Tire speed limitation on takeoff are not a consideration if the airport elevation is below:

Baseline GIV: 8,000 feet

SP 11,000 feet

TAKEOFF CLIMB SEGMENTS

Accelerate-Go Distance -- Takeoff roll and climb to 35' AGL

1st Segment -- 35' AGL to landing gear retraction
2nd Segment -- Gear retraction to 1500' AGL/flaps up

SECOND SEGMENT CLIMB GRADIENTS

Clearway 1.2% (runway lights may penetrate plane 6"-8")

Gross climb gradient 2.4%

Net climb gradient 1.6%

Note: Both GAC performance charts and the FMS compute Second Segment Gradient
of 2.4% to 400' AGL.

After 400' AGL performance improves enough to maintain minimum gradient to the
top of the Second Segment at 1500' AGL.

Eagle (KEGE) requires a 650/NM climb. That equates to a 10% gradient.

CALCULATING CLIMB GRADIENT RESTRICTIONS

Normal SID Climb Requirements: 360'/nm (360/6080=6% gradient)

To find the Max TOGW limitation for the required climb gradient:

 Take gradient to the Flight Safety/Gulfstream Normal Checklist (blue checklist)

page P-40
 Enter temp/PA and go up
 Enter gradient and go right to cross temp/PA vertical line
 Find Max TOGW

CLIMB GRADIENT RULE OF THUMB

Gulfstream IV Notes 4
Revision 2-98 Performance

To find required climb gradient quickly, look on SID for required climb rate versus
airspeed

Under 100kt speed find the feet/NM climb required and divide by 100 to find
required climb gradient

Example: If you are required to maintain 360 ft/NM at 100 KTS GS

The required climb gradient is 360/100 or 3.6%

ACTUAL OBSTACLE CLEARANCE CALCULATION USING THE FMS

To calculate actual obstacle clearance (as opposed to SID climb gradient) use the distance
from the end of the runway to the obstacle in feet.

The computer automatically factors in the additional distance (if any) between the lift
off point and the end of runway

Add AGL obstacle height to field elevation to obtain the MSL figure for use in the
computer -- enter the MSL figure for the obstacle.

If the obstacle distance is stated as a distance from the runway threshold, subtract the
runway length from the obstacle distance and enter that figure.

PERFORMANCE LIMITED TAKEOFF

Problem: If the runway is not sufficient for takeoff, no V-speeds are presented (Note:
This problem has been solved with the latest performance (PZ) software).

It is possible that runway is sufficient with balanced field numbers but they cannot be
adjusted because they are not displayed.

Solution:  Manually enter longer runway length in order to get V-speed computation.
 Adjust V-speeds to balanced field numbers.
 If resulting runway required is within available runway, box V-speeds and
delete manual runway length entry.

Miscellaneous Takeoff Notes

OIS-7 -- Written to address the situation at Aspen. (located in back of AFM)

APPROACH/LANDING CLIMB GRADIENTS

Approach Climb -- Based upon a single-engine, flap 20, gear up configuration.

Gulfstream IV Notes 5
Revision 2-98 Performance

Requires a minimum 2.1% climb gradient.

Landing Climb -- Based upon a two engine, flap 39, gear down configuration.

Requires a minimum 3.2% climb gradient.

OPERATING RULES OF THUMB (FROM FSI-SAV)

FUEL

Once BOW CG is calculated, CG will not change with fuel addition

400 lbs used for taxi allowance

Two Engine Ground Idle: 600 lbs/hr

T/O Thrust consumption: 6000 lbs/hr

3000 LB reserve typically used by operators

FLIGHT CREW REPORTS EXCESSIVE FUEL BURN

A GIV flight crew reported their aircraft was burning more fuel than when they first began
operating it. Previous investigation into items that would affect fuel burn had not resolved the
problem.

During recent conversations with their area Field Rep and Technical Services, the flight crew
reported they were carrying 3° right rudder trim during takeoff and cruise and removing the trim
during descent or low power settings. The left engine was burning 30 to 40 pounds more fuel per
hour than the right engine. With this information available, the fan air modulating valve was
suspected to be a contributor to the problem.

Technicians checked the fan air valve system for voltage going to the servo torque motor and
found the right side holding steady at approximately 14 volts. A check of the left side found the
voltage starting at 14 volts then degrading to 3.3 volts. When the temp sensors were swapped,
the problem followed the faulty sensor. A new sensor was installed, returning voltage readings to
normal.

The aircraft just returned from an overseas trip with the trim problem resolved and fuel flow
matched.

Comment: With the left fan air valve in a position other than closed, there were never any
complaints of insufficient heat in the cabin.
(GAC Breakfast Minutes – 7/14/98)

FliteStar® Flight Planning Software

Jeppesen/Mentor is nearing completion of a new version of their FliteStar® Flight Planning

Software. The software update will implement Honeywell FMS formats as an embedded feature
in their FliteStar® corporate line. With this version of the FliteStar® software, the user will have
Gulfstream IV Notes 6
Revision 2-98 Performance

access to state-of-the-art PC-based flight planning methods. This will be supported with the ability
to save the resulting flight plan to a disk and then subsequently load the flight plan into the FMS
on-board the aircraft. Jeppesen/Mentor is planning to include this feature in a version of FliteStar,
tentatively referred to as 7.1, targeted for release by NBAA. For additional information, contact
FliteStar Marketing Manager Dan McGaw at (303) 784-4590.
(Honeywell FMS Technical Newsletter – Summer 19970

MISCELLANEOUS

T/O Flaps -- Always use 20o flaps unless 2nd segment limited.

Routine Takeoff -- hold brakes to 1.5 EPR, then set Rated EPR on roll.
Climb Power Setting: Most operators use 650O TGT as target setting.

WAG FUEL BURNS

Hour Short Flight Long Flight

1 4500 4500
2 3500 3500
3 3000 2700
4 3000 2700
5 ----- 2700
6 ----- 2700
7 ----- 2700
8 ----- 2700
9 ----- 2700

Computer Flight Plans very good on GIV

Step Climbs – If the flight duration is less than 6 hours, a step climb will normally not be
required. Initial climb will not be restricted.

FMS Required Fuel Calculation – When entering Performance Initialization, enter zero
fuel to force the FMS to compute required fuel.

Route Planning Assumptions – Use M0.80 and ISA temperatures for general flight
planning.

The North Atlantic and Mid Pacific areas are normally warmer than ISA.
Gulfstream IV Notes 7
Revision 2-98 Performance

VMCG CALCULATIONS

VMCG is nominally set at 111 KT. Actual VMCG runs from 117-119 KT.

The FAA requires a one second recognition time be factored in resulting in reducing the
actual VMCG by 7 KT. (118-7=111 KT)

V1MIN is based on actual VMCG.

VMCG Crosswind Considerations

VMCG is calculated based on zero crosswind. VMCG increases with the crosswind
component. The upwind engine becomes the critical engine.

Pilots should consider using a V1 higher than V1MIN for takeoff (V1MIN = VMCG no wind) in
crosswind conditions to avoid controllability problems if the engine fails at V1.

AIRPORT SUITABILITY FOR GIV OPERATIONS

WARNING FLAGS THAT AN AIRPORT MAY NOT BE SUITABLE

Longest runway is 6,000’ or less.

Check runway/taxiway weight categories.

Check noise procedures/restrictions.
Check wet/slippery runway restrictions.
Check ramp space availability/suitability (thin asphalt in the summer?).

Jet fuel is not sold on field.

The airport may not be suitable for jet operations.

WHEEL LOADING

GAC considers that the weight at the nosewheel is 2,600 pounds regardless of
fuel/payload loading.

For wheel weight footprint, take the actual or planned gross weight of the aircraft
and subtract 2,600 pounds, then divide by two. This will result in the weight per
main gear.

Example: GIV TOGW - nosewheel loading: 63,000 lbs. - 2,600 = 60,400 lbs
Divide the result by two for a
per-gear loading of: 60,400  2 = 30,200 lbs
Gulfstream IV Notes 8
Revision 2-98 Performance

RUNWAY WEIGHT BEARING CAPABILITIES

ACN -- Aircraft Classification Number -- Aircraft rating at given weight

PCN -- Pavement Classification Number -- Airport rating published in airport directory

Used for determining maximum operating weight on runway

The ACN/PCN method was adopted some years ago by the International Civil Aviation
Organization (ICAO) as the worldwide standard for reporting pavement strength. This method
supersedes previous methods such as Load Classification Number (LCN) and Load Classification
Group (LCG). ACN is a number that expresses the relative effect of an aircraft on a pavement for
a specified standard subgrade strength. The two pavement types are flexible (asphalt) and rigid
(concrete). The primary input variables are: gross weight, percent load on main wheels, wheel
spacing, and maximum tire pressure. PCN is a number that expresses the bearing strength of a
pavement for unrestricted operations. PCN values are listed in various aeronautical publications
for individual airports. The PCN will be the allowable ACN for a given pavement. An airplane at a
known gross weight and tire pressure can use a pavement without restriction if the ACN is equal
to or less than the published PCN.
(GAC Service News -- April - May - June 1997)

PCN must be greater than or equal to ACN

PCN's apply to runways only, not taxiways or ramps

Check airport diagrams for taxiway restrictions

Call airport manager: "Have you had GIV's on your airport/ramp before?"

Avoid drain gratings (may be the weak point).

ACN/PCN information can be found in the Performance/Servicing Section of the Flight

Safety/Gulfstream Normal GIV Pilot Checklist, page P-56.

PCN RULE OF THUMB:

For an PCN below 15 -- can't operate a Gulfstream onto the runway (45,000 pound limit).

For an PCN above 26 -- can operate a Gulfstream at any weight (75,000 pound limit).

For an PCN between 15 and 26 -- may be able to operate, but must compute on the
ACN/PCN chart that isn't available.

Government airport facilities manual shows weight limitations as: S-80 D-140 DT-210
Gulfstream IV Notes 9
Revision 2-98 Performance

GIV uses the dual wheels category: “D-___”, or in the above example, a max
permissible weight of 140,000 lbs.

Note: Runways weight certified only within the painted sidelines. Taxiways, if certified,
only apply to center of taxiway.

AIRCRAFT MAIN GEAR SINKS THROUGH TARMAC

A GIV recently operating at a small midwest US airport sank through the asphalt. The crew was
making a right turn for runway lineup when the right main gear sank into the asphalt runway.
Shortly afterwards, the left main gear began to sink.

This type incident happens infrequently. However, Gulfstream would like to remind our operators
that although the runway length may be capable of handling your aircraft, the runway pavement
may not be capable of handling the aircraft’s weight or ACN (Aircraft Classification Number).

In this case, the aircraft carried 16,000 lbs. of fuel - slightly over half of the wing’s capacity. With
this fuel load, the aircraft’s ACN was 23. The airport runway’s PCN (Pavement Classification
Number) is not known, but the pavement was reported to be only 2-3 inches thick. After the fuel
load had been removed, workers lifted the aircraft using air bags and covered the holes in
cement.
(GAC Breakfast Minutes – 05/20/97)

WEIGHT & BALANCE

Aircraft Weight Gain: On re-weighing aircraft -- if weight goes up dramatically:

Service bulletins have added about 200 lbs over 3 years

If weight is considerably higher, may be water in insulation

Check door and belly insulation

Pitch Trim Chart is found in the recurrent training manual pg 7-19

Gulfstream IV Notes 10
Revision 2-98 Performance

GROSS WEIGHT INCREASE UPGRADES

EXISTING LEVELS OF ENHANCEMENT:

GIV Basic -- Baseline GIV

GIV IP Improved Performance -- ASC 266 -- Dunlop Brake-By-Wire
Wheels/Brakes/Tires
GIV SP Special Performance -- ASC 190 -- SP Weight increase w/ heavier
gear/Dunlop Wheels/Brakes/Tires
GIV AS Auto Spoilers -- ASC 314 -- Auto Ground Spoilers factored into landing
distances
GIV EN Enhanced -- Baseline GIV with ASC 349 -- FMZ-2000 conversion
GIV ED Enhanced IP with FMZ-2000 added (the “D” is for Dunlop Wheels)
GIV EP Enhanced SP with FMZ-2000 added
GIV ES Enhanced AS with FMZ-2000 added

The “E” in the above designations indicates FMZ-2000 equipment.

ZERO FUEL WEIGHT INCREASE

ASC 061 -- Zero Fuel Weight Increased to 49,000 (From 46,500 Lbs)

Available now

No real modifications -- A/S restricted to M 0.86/320 KT

Known as the Saudi ASC. Many of their GIV's have high BOW's. This ASC allows
them to carry a meaningful load.

ASC 190 -- Upgrades GIV to GIV SP

New landing gear, brakes, wheels, structural support – still a brake-by-wire system, but
utilizing the Dunlop wheels and brakes.

Original price: $1,000,000, now going for $700,000 (1998).

Zero Fuel GW: 49,000 Lbs

Max Ramp GW: 75,000 Lbs
Max Takeoff GW: 74,600 Lbs
Max Landing GW: 66,000 Lbs

GIV SP

SN 1215 And above are SP'S

Gulfstream IV Notes 11
Revision 2-98 Performance

Performance Improvements:

Change Baseline SP
Ramp Weight: +1,400 73,600->75,000
MZFW: +2,500 46,500->49,000
MGLW: +7,500 58,500->66,000
T/O Distance: +210 5,280---> 5,490
Lndg Distance: -180 3,380---> 3,200
Initial Alt: -400 41,500->41,100

Landing Distance is shorter despite heavier landing weight due to factored thrust
reversers.

The SP aircraft has become Category D for approaches.

ASC 320 -- Known as the “Aspen ASC” for SP/ASC 190 Aircraft.

Enhanced landing weight aircraft must currently use Category D for approaches. ASC
installs placard permitting Category C approaches if landing weight not greater than
standard 58,500#.

Performance Computer Upgrade

The Dash 920 (-920) Performance Computer was approved 01/94

Covers Enhanced Performance in ASC 190 & ASC 266 modified aircraft

GIV BASELINE TO SP UPGRADE OPTIONS BREAKDOWNS

SUMMARY OF THE ASC’S AVAILABLE TO UPGRADE
WEIGHT/PERFORMANCE

ASC 061 -- A paperwork ZFW increase to 49,000 lbs

ASC 190 -- A ZFW increase including heavier landing gear, Dunlop Brake-By-Wire
brakes, wheels and tires.
ASC 261--A ZFW increase to 49,000 lbs.
ASC 266 -- Changeover to Dunlop Brake-By-Wire brakes, wheels and tires.
ASC 307 -- Changeover to Dunlop HMAB brakes, wheels and tires.
ASC 350 -- A MGW increase to 75,000 lbs.
ASC 314 -- Credit for ground spoilers on landing distances (computer/paperwork
change).

ASC 261 & ASC 350 together are the equivalent of ASC 190
Gulfstream IV Notes 12
Revision 2-98 Performance

ASC 190 & ASC 307 together are the equivalent of a GIV SP (See GIV SP on page 18-?)

GIV OPTIMIZATION

CLIMB VS. RANGE

Best Angle of Climb to altitude will increase overall range

Found in GIV Performance And Operational Data Handout along with the best Rate
of Climb speeds

FUEL LOADS

Impact of reduced Fuel Density with increased temperatures:

With full fuel load there will be a decrease of 40 NM range with every 10o c increase
in fuel temperature.

Fuel load varies with fuel grade, temp of fuel, A/C altitude.

See table in the GIV Performance and Operational Data handout

Expect about a 1.8% decrease in fuel quantity for every 20 degrees of temp increase (and
visa versa).

Fuel Tankering -- GIV tab data in the GIV Performance and Operational Data handout

Weight Sensitivity -- See Tab Data in the GIV Performance and Operational Data
handout for cost in fuel for extra weight carried

SHORT RANGE OPTIMIZATION

Minimum Fuel Profile -- Best for short (1000 NM) trips

Minimum Time Profile -- High fuel price for small time savings

EARLY DESCENTS

Effects of Early Descents & Extended Approaches:

500-1000 lbs of extra fuel in busy terminals for Tay engined aircraft

1000-1500 for Spey engined aircraft

Gulfstream IV Notes 13
Revision 2-98 Performance

OIS-2

Found in back of the AFM.

Advisory data is in compliance with FAA procedures but not FAA approved.

Incorporates the James Brake Index (JBI)

Shows runway length required for runway conditions

In Contaminated T/O Data:  V1 decreases

 Distance increases

Equivalent Runway Contamination Based on Retarding Effect

 0.5" Water (maximum standing water limitation)

 0.6" Slush/Wet Snow
 1.3" Dry Snow (Loose)

BRAKING EFFECTIVENESS

 Dry Runway 100%

 Wet Runway 50%
 Icy Runway 1.5%
 Normal Rolling Resistance 5.5%

TAKEOFF ACCELERATION CHECK -- T/O PERFORMANCE MONITORING

Time to 90 Knots Tables

Numbers found in the GIV Performance and Operational Data handout
Check speed at calculated time
Not time at 90 KTS -- may never make 90 KTS

GULFSTREAM RANGE FIGURES FOR THE BASELINE GIV

3800 NM, No winds, 8 Pax, NBAA Reserves

Gulfstream IV Notes 1
Revision 2-98 Miscellaneous Information

19. MISCELLANEOUS INFORMATION

ONLINE RESOURSES

Information is power and the information now available on the World Wide Web is truly
spectacular. The following is a partial listing of what is available online and free for the
taking. If you don’t see what you are looking for, check one of the web sites below that
is related and more than likcly, there will be a hypertext link (jump button) to the site that
you are seeking. Or do a web search on one of the many web based search services.

Gulfstream World Wide Web Site -- Visit Gulfstream's web site at

www.gulfstreamaircraft.com. The available options are: Gulfstream Home Page; Corporate
Information; Aircraft; Links to Supplier Web Sites; and Gulfstream Customer Services, a secured
area requiring a user I.D. and password.

Also to be found on the Gulfstream web site): CMP, Manual, and CB Revision Status; and CMP
EDT Downtime Notice. You will be able to enter the “Customer Services” area and link to the
“Publications Support” page or “Computerized Maintenance Program” page for an update.

To access the Service Center regional sales manager information, enter the “Customer Services”
area and link to the “Service Centers” page. Go to the “Aircraft Services Contacts” page to find
the sales manager for your particular area. You will also find 24-hour hotline numbers for Spare
Parts Sales – 1-800-810-GULF(4853) and Technical Services – 1-800-422-5381

Breakfast Minutes Available Via Web Site and E-mail – The weekly Breakfast
Minutes are no longer available by fax and mail subscriptions. The information packed
Minutes are available for reading and download from the Customer Service section of the
Gulfstream Web Site. They are provided in HTML, Acrobat (.pdf) and Microsoft Word
(.doc) formats.

A Breakfast Minutes email subscription option is now available for those who cannot access
Gulfstream’s website. Each issue is sent out as a Microsoft® Word for Windows™ 2.0c document
that is zipped using WinZip 6.0a. E-mail subscribers must have Microsoft Word for Windows 2.0c
or higher and WinZip 6.0a or higher (or a comparable zip utility) to extract the Word document for
viewing or printing. If you have the correct software and would like to begin a Breakfast Minutes
e-mail subscription, send a message stating so to Gary Arms, Editor, Breakfast Minutes at:
gary_arms@mhsmail.gulfaero.com. Please include your name, company, aircraft operated (type
and S/N), and your e-mail address.

Service News Now On-line at Gulfstream's Web Site

Service News Discontinued -- Gulfstream has discontinued publishing the Service News. The last
published quarterly issue was 97-4 October-November-December 1997. More and more information
regarding our operator support has moved to the Gulfstream Web site and we felt this publication had
run its life cycle. Now we can relay information (such as Top 20 Removals and Field Service
contacts) in a more timely manner and you can gain more immediate access to it, while in your home,
office, or away.
Gulfstream IV Notes 2
Revision 2-98 Miscellaneous Information

The Service News Web site now contains the 1995, 1996, and 1997 issues, plus an index. All are in
Adobe™ PDF format.

AvPro Forum -- Visit Gulfstream’s section within CompuServe® Information Service’s Aviation
Professional (AvPro) Forum. You can now type “GO AVIPRO” to access this forum, then look for
the Gulfstream section.

MedAire Inc Internet Web Site -- Gulfstream’s medical consultant, has set up an Internet
web site. You can now use your favorite browser to access information about MedAire’s 24-hour
medical emergency hotline, medical training, first aid and medical kits, travel medicine information
services, defibrillators and defibrillator training, MedLink Inflight, passenger assistance services,
MedLink Worldwide, and MedLink Lifeline. The web site URL is: http:// www.medaire.com. For
more information, contact Gaye Johnson at MedAire, 1301 E. McDowell Rd., Suite 101, Phoenix,
AZ 85006. Telephone: 602-263-7971; fax: 602-252-8404; e-mail: information@medaire.com.
(GAC Breakfast Minutes – 02/18/97)

FlightSafety

FlightSafety’s corporate web site is located at: www.flightsafety.com.

FlightSafety’s Gulfstream Training web site at
http://www.sentex.net/~fsi/corslink/gulfstream.html.
FSI-SAV’s Director of Training is Dempsey Birmingham. His e-mail address is:
birminghamd@fsi007.flightsafety.com.
Other FlightSafety Savannah Training Center staff may be reached at
lastname + first initial@fsi007.flightsafety.com (use all lowercase letters and no spaces).

OTHER AVIATION WEB SITES OF INTEREST

AC-U-KWIK International Web Site — http://www.acukwik.com/

AC-U-KWIK ® has introduced a web site which accesses the company's databases.
You'll find the Airport FBO Search, an expansive directory of airports and FBOs that
includes coordinate information, elevation, hundreds of airport diagrams, plus
information on services and hotels. The Air Charter Guide section (also yacht charter)
offers an easy retrieval reference to hundreds of charter operators and brokers throughout
the world. In the Weather Information link, you can get local forecasts for any city in the
US, the latest satellite images, infrared, radar composites, severe storm warnings, and
jetstream information. Also available are 12, 24, 36, and 48-hour aviation forecasts.
Mapquest, a Java applet that allows you to find your way from any location in the U.S. to
any other location, is part of the experimental Global Positioning System.

 AOPA -- http://www.aopa.org

AOPA’s Airport Directory Now Available to Members on the Internet

Gulfstream IV Notes 3
Revision 2-98 Miscellaneous Information

Frederick, MD—The on-line edition of AOPA’s Airport Directory is now available free in the
Members Only section of AOPA Online (www.aopa.org). AOPA members can now use the
Internet to search the industry’s most comprehensive listing of airport information.

“With a few simple keystrokes, an AOPA member can get the essential airport information
needed to plan a flight,” said Seth Golbey, AOPA Internet Services managing editor.

The database for AOPA’s Airport Directory Online is constantly updated to ensure the airport
information is the most current and accurate available to AOPA. It includes records for more than
7,500 public and private-use landing facilities; 4,400 FBOs; and some 33,000 on-airport and near-
airport services.

A simple user interface allows an AOPA member to search for airports using a variety of
criteria. For example, a member can obtain a list of all the airports serving a particular city.
Members may search for airports using any combination of airport name, city, state, zip code, or
airport identifier. Other retrievable information includes: safety information, runway length,
communications frequencies, weather contacts, and FBO and facility information.

To access AOPA’s Airport Directory Online, go to the Members Only section of AOPA Online
(www.aopa.org) and click on the “AOPA’s Airport Directory” button. A simple on-line registration is
required for first-time users.
(GAC Breakfast Minutes – 8/11/98)

 ARINC -- http://www.arinc.com/
 ASRS Reports -- http://www-afo.arc.nasa.gov/ASRS/ASRS.html
 Aviation International News – http:// www.ainonline.com
 Aviation Week & Space Technology Magazine -- http://www.awgnet.com/
 Avweb aviation information website -- http://www.avweb.com/
 Bermuda -- www.dca.gov.bm -- Department of Civil Aviation
 Business/Commercial Aviation Magazine -- http://www.AWGNET.com/bca/
 DOT HAZMAT -- http://hazmat.dot.gov

The Office of Hazardous Materials Safety, which is within the United States Department of
Transportation's Research and Special Programs Administration, is responsible for coordinating a
national safety program for the transportation of hazardous materials by air, rail, highway, and
water. Visit their Web site for information on rules and regulations, international standards,
emergency response, and other related topics of interest

 Embry-Riddle Aeronautical University -- http://comm.db.erau.edu/

 FAA Web Sites — The FAA Aviation News is now on-line at the following URL:
http://www.faa.gov/avr/news/newshome.htm. Articles in the current issue and back
issues can be viewed.
 The FAA Aviation Safety Program web site is
http://www.faa.gov/avr/news/asphome.htm. On-line topics include Land and Hold
Short Operations, Reducing Runway Incursions, Surface Movement Guidance and
Control System, Aviation Safety Program "P" Pamphlets, and METAR/TAF.
 Federal Government Web Site -- http://www.fedworld.gov
 Honeywell -- http://www.cas.honeywell.com/bcas/index.html
 International Air Transport Association (IATA) – http://www.iata.org/8.33 -- for news on
the VHF comm 8.33 MHz spacing issue.
Gulfstream IV Notes 4
Revision 2-98 Miscellaneous Information

 ICAO -- http://www.icao.org/
 Jeppesen-Sanderson -- http://www.jeppesen.com/
 Jet Aviation -- http://www.jetaviation.com
 Jet Professionals -- http://www.jet-professionals.com
 Landings – http://www.landings.com

Aviation enthusiasts worldwide have made Landings one of the best aviation directories/info
sources on-line. Landings' directory will connect you to virtually every lift-generating web site on
the net, from airports to flying clubs, organizations and publications to aviation events, home-
building to airlines, and many more. Landings is an active community featuring biweekly news,
professional pilot resources, aviation databases, and expert mediated discussion forums. Among
Landings various databases you will find sophisticated searches of FAA Regulations, Canadian
Regulations, AIM, the Pilot Controller Glossary, Service Difficulty Reports, Airworthiness Alerts,
NTSB Briefs, N Numbers, the FAA Airmen Database, Airmen Knowledge Test Information, and
more.

Landings’ Aviation Directory includes the following areas of interest: Aerobatics-Flying,

Aircraft-Sales, Aircraft-Service/Parts, Aircraft-Manufacturers, A/C Values, Airlines, Airports,
Airshows/Events, Aviation-BBSs, Aviation-Images, Aviation-Lists, Aviation-News-Groups,
Avionics, Classifieds, Companies, Databases, Flight-Schools/FBOs, Flying-Clubs, Flight-
Planning, General-Aviation, Government/Research, GPS/Technologies, Hang Gliding/
Paragliding, Helicopters/Gyrocopters, Homebuilding, Lighter-than-Air, Military,
Miscellaneous, Museums/History, Organizations, Pilot-Supplies, Publications, Regional,
Regulations, Reports/Alerts, Schools, Simulators, Skydiving, Soaring, Training, Travel/Tours,
Ultralights, Various-Products/Services, and Weather.

As one aviation publication commented about Landings: "If you can't find it here, it isn't on the
Web."
(GAC Breakfast Minutes – 4/28/98)

 Master Minimum Equipment Lists --

http://www.aerolink.com/regulatory/mmel.html
 NBAA -- http://www.nbaa.com/

NBAA Air Mail — NBAA Air Mail is a series of e-mail mailing lists, or "users
groups," set aside for collaboration and discussions on topics of interest to business
aircraft operators. Any e-mail message sent to an Air Mail list address is broadcast to
everyone on that list. Through Air Mail, NBAA Members (and employees of Member
companies) can communicate their concerns, questions, gripes, and insights with their
fellow Members on any topic relevant to the group. Best of all, messages posted to
the Air Mail groups will be archived on NBAA's Web Site, creating a living
institutional memory of issues of the day. Web site visitors can read all messages
posted to the Air Mail groups, and can sort messages by date, subject, author, or
thread. It's easy to subscribe to the Air Mail lists, and like NBAA's Web site, Air Mail
is a free service provided to NBAA Members and employees of Member companies.
The URL is http://www.nbaa.org/member/airmail/welcome.htm.

NBAA's Airport Database Has Over 2,500 Reports -- Many years of gathering member reports
have allowed the National Business Aviation Association (NBAA) to create an archive of
information about specific airports around the world. Reports on everything from aviation issues
Gulfstream IV Notes 5
Revision 2-98 Miscellaneous Information

to facilitation and local accommodations are available. There are more than 2,500 airport reports
in the database. Upon query, results are displayed in reverse chronological order, most recent first.
Although primarily international, the database does contain domestic airport reports. Member
companies can query NBAA's airport database at:
http://www.nbaa.org/member/airport/iobsearch.htm.

All submissions, domestic or international, are encouraged. Submissions can be made at:
http://www.nbaa.org/member/airport/enteriob.htm.

Federal Excise Tax Handbook on NBAA Web Site -- The National Business Aviation
Association (NBAA) recently published the 1998 Federal Excise Tax Handbook. This book
explains how the IRS Rules and the FAA Regulations work together. Also, it tells how the federal
excise taxes apply to Part 91 and Part 135 operations. The Federal Excise Tax Handbook is now
posted on NBAA's Web site at http://www.nbaa.org/
member/politics/taxissues/excisebook/welcome.htm. Major headings include: Federal Excise
Taxes on Aviation; Enforcement; State Taxes on Aviation; Related Examples; and IRS Tax Rules
Synopsis. IRS Forms 720 and 8849, and Publication 378 are available in Adobe Acrobat PDF
format.

 NTSB -- http://www.ntsb.gov/Aviation/Aviation.htm
 Oceanic Operations Information (RNP-10) --
http://www.faa.gov/aua/ipt_prod/oceanic/rnp.htm
 Pro Pilot Magazine -- http://www.flightdata.com/propilot/
 Related Gulfstream Web Site Directory -- http://home.att.net/~doug.gordon/
 RVSM Information -- http://www.arinc.com/Ind_Govt_Srv/RVSM/rvsm.html
 Transport Canada –http://www.tc.gc.ca/aviation/

Anyone flying in Canada will find Transport Canada’s Civil Aviation web site helpful. Visit
www.tc.gc.ca/aviation/index.htm for information about safety issues, events, publications, and
regulatory changes. You can also search by branch (General Aviation, Commercial and Business,
Regulatory Services, etc.) or region (Atlantic Region, Quebec Region, Ontario Region, etc.).
Quick Reference topics include Airworthiness Directives, Canadian Aviation Regulations
(CARs), and Master Minimum Equipment List (MMEL). You can also read press releases and
find out more information about Transport Canada’s organization.
(GAC Breakfast Minutes – 4/14/98)

Hurricane, Weather, and Volcano Web Resources

 Aviation Weather Center -- http://WWW.awc-KC.NOAA.gov/awc/Aviation_Weather_

Center.html
 EarthWatch -- http://www.earthwatch.com 3-D weather information and forecasts
 The Federal Emergency Management Agency (FEMA) Tropical Storm Watch --
http://www.fema.gov/fema/trop.htm
 Landings -- http://www.landings.com click on weather link
 National Weather Service Interactive Weather Information Network -- http://
iwin.nws.noaa.gov/iwin/graphicsversion/main.html
 Storm 98 Hurricane Central -- http://www.storm98.com FEMA is co-sponsoring this web site.
 The Weather Channel Aviation Weather -- http://www.weather.com/aviation
 Universal Weather and Aviation Inc. -- http://www.univ-wea.com
 VolcanoWorld -- http://volcano.und.edu
Gulfstream IV Notes 6
Revision 2-98 Miscellaneous Information

 WeatherNet -- http://cirrus.sprl.umich.edu/wxnet

FSI/GULFSTREAM EMERGENCY/ABNORMAL CHECKLIST

A new approach to locating troubleshooting checklists must be followed when using the
new red FSI/Gulfstream Emergency/Abnormal Checklist because of changes in the
organization of the procedures.

All red warning (urgent) items are located under the Red Warning Messages tab in the
front of the checklist, pages E-1 through E-11. These messages are organized in
alphabetical order as they have been in the past.

The amber messages are now organized by system type such as avionics, electrics,
engines, flight controls, etc beginning on page E-13. The malfunctions that result in an
amber message are grouped at the front of each system type. A failure message such as R
CONV FAN FAIL would be referenced in the front of the ELECTRICS tab area where all
electrics related messages are located. An index is printed on the first page of each
system tab section, referring to the numbered tab within that system area in which the
corrective procedure/checklist may be found.

Blue messages are listed together in a Blue Advisory Messages section starting on page
E-153 of the checklist following the systems malfunctions area. The blue message
section contains a traditional listing of blue messages with associated explanations or
procedures to follow.

For problems that generate just one CAS message, the full corrective procedure will be
covered in the red message tab section or in the amber message section of the respective
system malfunction section. In the case of red warning messages, the procedures are
clearly concluded with the < END > indication or referred to another section for followup
treatment using a go to instruction such as the following example: < GO TO PAGE E-
147; MISC, TAB-3 >.

Some malfunctions either don’t produce a warning message or cause multiple warning
messages associated with other effected equipment and systems. An example of this
would be the failure of a Corrective actions for these malfunctions will be covered in the
Emergency/Abnormal Tab (yellow) behind the Blue Message Section.

If a Note or Caution follows a checklist item, it refers to the preceding item. Read the
Note or Caution before executing the item to which it refers.

A very useful index is included in the back for fast location of a problem. It is divided
into red warning messages, amber caution messages, emergency/abnormal procedures
and blue warning messages mirroring the organization used in the body of the checklist.
Gulfstream IV Notes 7
Revision 2-98 Miscellaneous Information

GAC HELPLINE CONTACT NUMBERS

Switchboard (24 Hours) 912-965-3241

After Hours 800-422-5381
Field Service (Marsha Grovenstein) 912-965-3253
Customer Service (Danny Langford) 912-965-4724
Flight Operations (Ted Mendenhall) 912-965-3642
Flight Sciences (Ed Flinn) 912-965-3563
Technical Services (Sandy Wiggins) 912-965-3249

Customer Frequency (Business Hrs) 128.92 MHZ

GAC Helpline Card 10/91

REMOTE INTERNATIONAL OPERATIONS

Inform GAC Field Service Office

They will inform client of appropriate Support Personnel and put them on notice

Client may want to include GAC Field Service Personnel names in applying for visas to allow
rapid response if needed
(GAC Breakfast Minutes -- 04/16/91)

TAY NOISE CERTIFICATION

Gulfstream is providing a notarized manufacturer noise certificate for proof of noise compliance in
Europe

Contact Technical Ops: 912-965-3247

(GAC Breakfast Minutes -- 01/18/94)

May need up to ten copies.

FSI student reported that Frankfurt wanted a seal on their copy.

NBAA Airport Noise Summary —The National Business Aircraft Association's 1996-1997 Airport
Noise Summary is now available. The 40-page booklet covers 622 US airports (with identifier and
runway length), arranged by states and outlining noise restrictions and a local phone number to
call for more information. Also included is information on the Airport Noise and Capacity Act and
FAR Part 150 rules concerning aircraft noise restrictions. Data on aircraft selection, European
operations, noise category definitions (Stages 1, 2, and 3, or Chapter 1, 2, and 3 in Europe), and
Stage 2/Chapter 2 retirement requirements are included in the booklet. Airport Noise Summary
information is also available on the NBAA's World Wide Web site at http://www.nbaa.org.

For a copy of this informative booklet, contact the NBAA at 1200 18th St. NW, Washington, DC
20036 / 202-783-9000 (phone), 202-331-8364 (fax).
Gulfstream IV Notes 8
Revision 2-98 Miscellaneous Information

(GAC Service News -- January-February-March 1996 )

ADVERSE WEATHER AND SAFETY REMINDERS

GIV AIRPLANE FLIGHT MANUAL APPENDIX E

ADVERSE WEATHER CONDITIONS/ABNORMAL ATMOSPHERIC
CONDITIONS

This major change was included in AFM Revision 14, dated October 18, 1996.

The following was taken from an article in the Gulfstream Breakfast Minutes.

Appendix E has a wealth of information for flight and ground operations and is a good resource
for maintenance technicians as well as pilots. This section contains only those procedures which
differ from or add to the AFM Normal Operating Procedures. These procedures are not intended
to address all Abnormal Flight or Adverse/Cold Weather Operational Procedures.

The following topics are included:

• Cold Weather Operations

• Securing Aircraft for Overnight or Extended Periods
• Wet Runway Conditions
• Weather and Tire Conditions
• Ground De-icing and Anti-icing Procedures
• Hot Weather Operation
• Desert Operation
• High Elevation Airports
• Windshear and Microbursts
• Volcanic Ash Encounter
• Heavy Rain/Hail Encounter
• Turbulence Penetration/Severe Gust Encounter
• Bird Ingestion
• Lightning Strike
(GAC Breakfast Minutes –02/11/97 )

COLD WEATHER OPERATIONS

Delay turning on cockpit systems such as DU's, IRS's and radios until cabin temperatures
are up to 50 F to avoid spurious failure messages and indications.
(AFM C-11 4 FEB 94).

Engine Pre-Heat
-- In a prolonged cold soak situation, preheat engines and APU if possible. If not
possible, after APU start and stabilization:

1. Turn A/C packs-OFF

Gulfstream IV Notes 9
Revision 2-98 Miscellaneous Information

2. Open Cowl Anti-ice Valves for 10 minutes to provide some preheating.

3. Run each engine thru a crank cycle achieving maximum levels of 5-6% LP and
02-22% HP.

4. If start valve doesn't open, repeat cowl anti-ice preheat another 10 minutes and
re-attempt. If still no start valve, operate manually until moves freely (air off)

5. Before opening HP cocks, allow each engine to achieve 20-22% HP and 5-6%
LP and visually check for LP fan movement outside.

6. Be alert for a hot start.

(AFM C-12 4 FEB 94)

How to Avoid or Minimize the Potential for Frozen Brakes

There have been two recent incidents of frozen brakes causing a blown tire upon landing. As a
result, we are repeating a 1/25/94 Breakfast presentation by John O’Meara, Gulfstream Flight
Operations. How To Avoid Or Minimize the Potential For Frozen Brakes

There have been three recent incidents of frozen brakes coincidental with record severe cold
weather in the Midwest and Northeast United States. All three events involved GIV airplanes.
Two airplanes had brakes frozen on the ramp. This was discovered prior to aircraft movement:
one prior to departure, the other before moving into a hangar. The brakes were Gulfstream
history. In 1991 a GIV reported a frozen brake incident. In 1988 a GIII encountered a frozen
brake. In 1985 a GII had a frozen brake. "It looks like we’re on about a three-year cycle," John
observed. "In 1997 we might have a GV. We don’t know."

All three recent incidents involved Dunlop carbon brakes. However, we have found that all brakes
are susceptible to freezing, whether they be steel, ABS carbon, or Dunlop carbon.

Other manufacturers report frozen brakes -This condition is not just peculiar to Gulfstream
aircraft. We’ve checked with other manufacturers and found that their aircraft are affected as well.
Boeing, which uses a variety of brake vendors, has seen this condition. Lockheed and Douglas
confirmed the same thing.

Procedures To Minimize Potential For Frozen Brakes

Parking/Ramp Positioning
* Avoid puddles and slush when possible.
* Chock wheels.
* Release Parking Brake.

Walkaround
* Check brakes, wheels, and wheel wells for snow, slush, or ice. Clean with mechanical means.
Use hot air for frozen brakes. Avoid chemical deicer.

Engine Start
* Set brakes just prior to engine start.

Taxi
* Taxi as soon as possible after engine start.
* Avoid puddles and slush when possible.
Gulfstream IV Notes 10
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* Use brakes to build up heat to dissipate moisture. 100° or slightly higher should dissipate any
moisture in the brakes.
* When stopped, perform several brake applications to 3,000 PSI. This exercises the brake
stacks and discourages ice buildup.
* Avoid the temptation to set the parking brake for any length of time.

After Takeoff
* Delay gear retraction if practical. This allows water, slush, and snow to be slung off.
* If possible, cycle gear once or twice.
* Recommended to wait for wheel spindown.
* Briefing of passengers is recommended.

Approach -- Gear Down

* Gear will assimilate the total air temperature in 3 to 5 minutes.
* Perform several brake applications to 3,000 PSI.
* Brake-by-Wire - Turn Anti-skid Off or use Brake

Nutcracker Override Switch.

* GII/GIII/HMAB GIV --Turn Anti-skid Off.
* Make sure Anti-skid is On for landing.

Landing
* Perform firm touchdown to reduce strength of ice bond on brakes (good idea to brief
passengers).
* Use firm braking techniques, dependent on run way conditions, following thrust reverser
deployment.

Taxi In/Parking
* Avoid puddles and slush.
* Chock wheels.
* Release Parking Brake.
* Hangar the aircraft ASAP.

Post flight
* Check wheels, brakes, and wheel wells for contamination.
Clean as necessary.

John indicated he has received questions about using wing anti-ice to warm the wheel wells.
Service experience has shown this produces some residual heat and may be helpful on GII and
GIII aircraft. It is of no help on the GIV aircraft.

Note: See ASC 381 below for additional information.

(GAC Breakfast Minutes – 01/25/94, reprinted in the 9/01/96 Minutes)

ASC 381: Main wheel well heat

PURPOSE: Changes the plumbing of the wing anti-ice bleed exhaust duct to increase
warming air flow to the wheel well area for brake warming. . (Due 2nd
Qtr. ’97.)

GROUND DEICING OPERATIONS

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Turn bleed valves off during de-icing to avoid cabin environment contamination due to
entry of deicer into the APU/engine intakes.
(AFM 2-16 15 JUL 94)
(AFM C-14 4 FEB 94)

Care must be taken to avoid contaminating APU and engine intakes with glycol deicing fluids.

Leads to fumes in the cabin air

If deicing contamination is suspected:

 Clean water separator socks

 Operate air-conditioning system at full hot to purge the system
 If the contamination continues, may be internal APU or engine oil leakage
(GAC Breakfast Minutes -- 02/15/94)

Shut Down APU for Aircraft Deicing/Anti-icing

A GIV operator reported that deicing fluid was ingested by the APU during deicing of the aircraft.
This is a reminder that the respective Gulfstream Airplane Flight Manuals require that the APU be
shut down and the inlet door closed during deicing operations. If the APU has ingested deicing
fluids, we recommend that the operator contact AlliedSignal for corrective action to clean the APU
of deicing fluids.

(GAC Breakfast Minutes – 09/08/96)

Securing Basics for Overnight or Extended Periods on Ramp in Cold Weather

The following information is taken from an article in the Gulfstream Breakfast Minutes and is
based on information from GIV Airplane Flight Manual Appendix E, Adverse Weather/ Abnormal
Atmospheric Conditions.

If remaining overnight or for extended periods during cold weather at airports where normal
support is unavailable, the flight crew should ensure the following actions are accomplished.

• Outflow Valve - Closed

• Wheel Chocks - In place

Do not leave aircraft parked in standing water that could freeze overnight.

• Parking Brake - Off

If brakes should freeze, use warm air, not chemicals, to thaw them.

• Protective Covers and Plugs - Installed

A written checklist will ensure all required items are installed.

• Water Storage Compartments - As required

Service potable water and waste water tanks as soon as possible after a flight. Table 1
indicates if it is necessary to drain or not (depending on the ambient temperature and the
Gulfstream IV Notes 12
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cold soak period). Ensure there are no residual fluids before you install the fill/drain caps.
When the temperature is below 0°C (32°F), drain valves can remain open to allow
residual fluids to vent. Drain all the galley equipment, such as coffee makers and water
boilers/heaters, which contains water. Also remove sodas, bottled water, wine, etc. - any
liquid that could freeze and soil the cabin interior should the container burst.

Table 1
Air Cabin Outside Air Cold Soak Time Water Tank
Cond. Temp. Temperature (Hours:Min) Drain

ON Above 10°C • Between 0° and Any Not Required

(50°F) - 7°C (32° and 19.4°F)
• Between 0° and 1:30 Required
-15°C (32° and 5°F)

OFF • Between -7° and : 0:30 Required

-15°C (19.4° and 5°F)
• Below -15°C Any Required

Note: As this article was being prepared, the Table 1 outside air temperatures with the Air
Conditioning ON were found reversed, and an AFM publications change was initiated. They are
correct above. If conditions do not permit draining of the galley equipment, the following heating
recommendations table should be used.

Ramp External APU Draining of

Temperature Heater Heater Water System

0°C ( 32°F) 1 Hour 1 Hour No

to Every Every
-5°C (23°F) 4 Hours 4 Hours

-5°C (23°F) 2 Hours 2 Hours No

to Every Every
-10°C (14°F) 4 Hours 4 Hours

-10°C (14°F) Continuous Continuous No

to
-15°C (5°F)

Below Continuous As Required Yes

-15°C (5°F)

• Toilets - Drained

• Batteries - Removed

If the nickel-cadmium batteries will be exposed to temperatures below -18°C (0°F), the batteries
should be removed and stored in a place warmer than -18°C (0°F) but below 40°C (104°F).
Gulfstream IV Notes 13
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• Doors - Closed

Remember to close the APU inlet door, in addition to the main entrance door, baggage door, and
other access doors. Some procedures for specific or unique operations should be addressed or
added as needed by an individual operator.
(GAC Breakfast Minutes –02/18/97)

PRODUCT TESTING LEADS TO APPROVAL OF UNION CARBIDE TYPE IV

DE-ICE FLUID

Gulfstream has recently reviewed the qualification test data on three different Type IV de-ice
fluids for possible use on Gulfstream aircraft.

We received data on:

• Union Carbide Ultra + Type IV
• Hoeschst AG Safewing MP Type IV and
• Kilfrost ABC-S.

After examining the remaining fluid thickness on the wing surface following high speed ramp
acceleration tests, the only product which provided acceptable results was the Union Carbide
Ultra +, when diluted 50:50 with water.

The use of Union Carbide Ultra + is Gulfstream approved for use on Gulfstream aircraft, provided
the fluid is diluted in a 50:50 minimum mix of product and water. Additional info on use and
dilution ratios will be addressed in a Flight Manual Supplement Revision.

Two other Type IV fluids have qualification test data available. When that data is received,
Gulfstream will evaluate it for possible approval.
(GAC Breakfast Minutes – (12/02/97 )

FAQ AND NOTES ABOUT TYPE IV DEICING FLUID

A Gulfstream operator recently posed several questions about Type IV deicing fluid to Breakfast
Minutes. What follows is Engineering’s response. Please note that Gulfstream has only approved
Union Carbide (UCAR) Ultra/Ultra+ Type IV fluid; therefore, these answers only relate to that
compound.

Q -- Does Type IV deicing fluid work cold or does it have to be heated?

A -- UCAR Ultra Type IV may be used cold as an anti-icing agent, but tests indicate that Type IV
fluid is most effective as a deicing agent when heated and applied to the surfaces under high
pressure (see question 3 response). As an anti-icing agent, it is most effective when the fluid
layer is .04 to .11 inches thick; too thin and its effectiveness is significantly reduced, too thick is a
waste of fluid.

The temperature of the heating apparatus that comes in direct contact with the fluid must not
exceed 120°F or thermal degradation and loss of fluid effectiveness will occur.

Q -- Can it be carried on the aircraft?

A -- The chemical is a glycol formulation; therefore, we would advise against it.

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The tests indicate that the toxicity level of the UCAR Ultra Type IV fluid is below that of pure
ethylene glycol. However, exposure to glycol vapors in a poorly ventilated area may cause
nose/throat irritations, headaches, nausea, vomiting, and dizziness. Ethylene glycol formulations
are moderately toxic for humans. Ingestion may cause abdominal discomfort, pain or dizziness,
and can affect the central nervous system.

Anyone handling these fluids should be fully aware of the health effects and protective clothing
required. Detailed information is generally contained in the material safety data sheet (MSDS)
available from the fluid manufacturer.

Ethylene glycol is regulated as a hazardous substance in some states.

Q -- Could it be carried in a garden type sprayer for emergency use in a quick-turn situation?

A -- Generally, no. For overnight anti-icing applications, the garden sprayer technique may be
used. As an anti-icing agent, it is most effective when the anti-icing fluid layer is .04 to .11 inches
thick; too thin and its effectiveness is reduced, too thick is a waste of fluid.

To one-time properly coat a GIV wing upper surface would require: (950 square feet wing surface
area) x (144 square inches/square foot) x (0.04 inches of fluid thickness)/(231 cubic
inches/gallon) = approximately 24 gallons of fluid.

For deicing applications using fluid, hot fluid sprayed under pressure is the preferred and most
effective method of deicing an aircraft. Deicing is typically achieved by applying a high velocity
stream of hot fluid. The thermal and mechanical energies of the hot fluid melt, dislodge, and
flush away frozen accumulations. Sufficient fluid should be used to ensure complete removal of
the frozen deposits.

UCAR Ultra Type IV is described as non-corrosive. Long-term storage should be in opaque

containers, since ultraviolet radiation (UV) will degrade the viscosity of the fluid. The
recommended storage containers are dedicated tanks of: carbon steel, coated carbon steel,
stainless steel, fiberglass reinforced polyester, or aluminum.

Other Notes of Interest

Trained Personnel – Only trained personnel should be permitted to deice aircraft. Insufficient
knowledge and improper technique may be detrimental to safety as much as an iced-over wing
surface. Knowledge required, for example:
 UCAR Ultra may not be used on helicopters.
 Type IV deicing fluid thickeners can be degraded by mechanical pumps. Special low
shear pumps and nozzles are recommended when pressure spraying Type IV fluids.
 Intentional or unintentional dilution of the fluid raises its freezing point. Proper use of
deicing fluid formulations generally requires that the freezing point of the mixture be determined
before the application. A portable refractometer can be used in the field to determine the
suitability of the fluid. Refractometers such as the Misco 10431 VP or Leica 753L are hand-held
units that can be used in the field.

Charts are available from the fluid manufacturer that allow determination of the mixture freezing
point. For UCAR Ultra, charts plotting the refractive index in degrees "Brix" vs. fluid freezing point
are available.

Type IV fluids were developed for large transport aircraft. The undiluted (neat) Type IV fluid is
intended to shear off of the wing at no more than 150 knots. Some Type IV fluids were found to
jell when drying out, leaving residue contaminating the wing surface, thus affecting aerodynamic
performance. All traces of the anti-icing/deicing fluid must depart the wing surface before rotation
speed (Vr) is achieved. Residual fluid remains do have a detrimental effect on wing lift.
Gulfstream IV Notes 15
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All deicing fluids are tested in a wind tunnel by an independent agency to determine the effect of
the fluid, at various standard mixtures, on the aerodynamic characteristics of the wing. The wind
tunnel startup characteristics model the aircraft’s acceleration to a standard defined Vr speed.
That data is published and provided to the airframe manufacturer for use in determining whether
the fluid/fluid mixture is acceptable for use on their particular aircraft.

Note: Gulfstream has not approved any Type II or Type IV fluid in concentrations higher than
50/50.

FAA Holdover Charts – The FAA publishes an update to the anti/deicing fluid holdover charts
every September. The charts are published in a Flight Standards Information Bulletin For Air
Transportation (FSAT) available for download at the FAA web site www.faa.gov/avr/afs/fsat/. This
year’s bulletin number is FSAT 97-10B: FAA-Approved Deicing Program Updates, Winter 1997-
98 Amended. The publication also contains informative and updated information on deicing fluids,
uses, pitfalls, etc. that have been found during the past year. FSAT bulletins for previous years
are also available.

Similar information can be obtained from Transport Canada's web site at www.tc.gc.ca/aviation/
by searching the publications for anti-icing or deicing related publications. Transport Canada's
version of FSAT 97-10B is Air Carrier Advisory Circular (ACAC ) No. 0113R, Title: Aircraft
Ground Icing Update. Other Air Carrier Advisory Circular's dealing with anti/deicing are also
available.

Russian Arktika – In regards to Russian Arktika anti/deicing fluid, very little is known in general.
We have requested information from several Russian organizations but with little success to date.
Our contacts that belong to SAE/ISO organizations dealing with aircraft anti-icing/deicing
technology have stated that, to their knowledge, there is currently no Russian participation in any
international forum dealing with aircraft icing issues.

What is known is that Arktika is an ethylene glycol-based fluid with a thickener added. Some
references have been made among users that it is a Type I &1/2 fluid; that is, it is a Type I anti-
icing fluid with an additive to increase its viscosity, reducing its tendency to flow off the wing. It is
generally a Type I anti-icing fluid with a level of increased viscosity that is found in Type II fluids.
Arktika is described as a transparent, colorless, slightly yellow liquid without smell. It is used both
as an anti-icing and deicing fluid. Arktika is not certified to any SAE/ISO standard.

We have not been able to obtain any holdover chart type data for this fluid, or the chemical
formulation of the thickener additive to ascertain its chemical safety or long-term effect on aircraft
materials. US Military (MIL-A-8243D) glycol based anti/deicing fluids contain corrosion inhibitor
compounds as part of the formulation. We also have no data on the fluid’s aerodynamic effects.
Until further data is obtained, Gulfstream recommends that any use of Arktika be avoided where
possible and SAE/ISO fluids be used.
(GAC Breakfast Minutes – (01/13/98 )

Arktika 2000 – Reported to be toxic and caustic to paint.

CLOSE ENTRANCE DOOR FOR INCLEMENT WEATHER AIRCRAFT

TOWING

A Gulfstream operator reported a situation that happened as they were towing their aircraft
across an icy ramp with the main door closed. The tug lost traction and began to slip. As the
aircraft continued its forward momentum, the tug swung to the left side of the aircraft then under
the fuselage. No one was injured and the only damage was a broken antenna. Had the main
Gulfstream IV Notes 16
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entrance door been open, the damage would have been worse with possible injury to the tug
driver. This brings us to the point. When towing your aircraft in inclement weather, take whatever
precautions are necessary, verify the tug is of proper size, and use wing walkers and a cockpit
brake man. It is also a good idea to close the main entrance door, as was the policy of this
operator.
(GAC Breakfast Minutes – 02/25/97)

HOT WEATHER OPERATION TIPS

The following general information, although excerpted from GIV AFM Appendix E - Adverse
Weather/Abnormal Atmospheric Conditions, applies to all aircraft. Hot weather operation
generally means operation in a hot, humid atmosphere. High ambient ground temperatures have
a pronounced effect on aircraft and crew performance, and operating efficiency. High
temperatures, alone or coupled with high humidity or blowing sand and dust, will complicate
normal operations. High humidity usually produces condensation throughout the aircraft, which
will cause the following: • Malfunctioning of electrical and electronic equipment

• Fogging of instruments
• Growth of fungi in vital areas of the airplane
• In extreme cases, pollution of lubricants, hydraulic fluid, and fuel.

Here are selected recommendations for operation in hot climates:

• Closely monitor strut servicing and aircraft level.

• Inspect for leaks where seals may have swollen.
• Limit the use of brakes during taxi and after landing to prevent overheating. Idle reverse thrust
can be used on clean taxiways to help reduce brake usage.
• Examine the effects of high temperatures on aircraft performance, especially at high altitudes.
• Give the engines extra time to cool after shutdown before installing plugs/covers.
(GAC Breakfast Minutes – 04/15/97)

DIGITAL AIR DATA COMPUTER (DADC) IN-FLIGHT FAILURE DUE TO

OVERHEAT CONDITION

A GIV operator reported that the DADC #1 on his aircraft partially failed while en route from
Monclova, Mexico to San Antonio, Texas. This incident may be one to blame on El Nino and the
unusually hot weather conditions recently experienced in the southwestern U.S. and Central
America. During the flight the autothrottles disconnected, but the radar and pressurization
systems were functioning normally. Switching over to DADC #2 corrected the situation.

Upon landing in San Antonio, the crew switched back to DADC #1 and it appeared to function
normally. Further conversations between the crew and the on-site representative noted that the
aircraft had sat on the ground for over 2½ hours in Monclova with the auxiliary power unit (APU)
running and both the main entry door and the baggage door open. The outside air temperature
before departure was well over 100°F. This incident involved an early GIV, manufactured before
S/N 1156, which does not have the improved radio rack cooling modifications.

It was determined that not having these radio rack cooling modifications, combined with the open
main entrance door and baggage door, caused an overheating condition. The technician that
swapped the DADC units stated the #1 unit was very hot when it was removed.
Gulfstream IV Notes 17
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Gulfstream suggests that when operating your aircraft in a hot environment, the main entrance
door and the baggage door be kept closed until the passengers arrive. This will help maintain
adequate cooling. This should be observed on all aircraft, but is especially essential for those
aircraft where improved radio rack cooling modifications have not been installed or been
equipped during production.
(GAC Breakfast Minutes – 8/4/98)
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HIGH ELEVATION AIRPORT OPERATIONS

Effects of High Elevation Airports on Engine Start

The following information was taken from GIV AFM Appendix E, Adverse Weather/Abnormal
Atmospheric Conditions. Service News 95-3 contains GII/III suggestions for operating at airport
altitudes of 7,000 ft. or higher. The information has been submitted for inclusion in an Operational
Information Supplement. Be alert for higher than normal TGT and the possibility of a warm or hot
start.

Right Engine

• If you use the APU as an air source for starting the right engine, reduce APU alternator electrical
loads to provide maximum airflow.
• Utility Pump - Off. Caution: Ensure wheels are chocked and parking brake accumulator is fully
charged.
• Boost Pump - One On
• Crossflow Valve - Open
• Ram Air Switch - Ram
• Airstart Ignition - On (for S/N 1144 and subsequent and earlier aircraft with ASC 151)
• HP RPM - 16 to 22% - Max available
• HP Fuel Cock - Open
• TGT - Monitor

After engine stabilizes at idle

• Airstart Ignition - Off

• Utility Pump - On

Left Engine

• Increase available bleed air using right engine (if required)

• HP RPM - 16 to 22% - Max available
• Airstart Ignition - On (for S/N 1144 and subsequent and earlier aircraft with ASC 151)
• HP Fuel Cock - Open
• TGT - Monitor

After engine stabilizes at idle

• Airstart Ignition - Off

• Right Engine - Reduce to idle
• Utility Pump - On

Taxi

Ground idle speeds may be lower than required to keep the alternators on line. It is
recommended that the APU remain running with the APU alternator on for all ground operations.

(GAC Breakfast Minutes – 07/22/97)

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ADVERSE WEATHER TIP - FLIGHT THRU HEAVY RAIN/HAIL

Monday’s heavy rain in the Savannah area served as a reminder of procedures for a heavy
rain/hail encounter. The thunderstorm season is upon us. Spey and Tay engines are tolerant of
normal in-flight water ingestion. However, heavy rain/hail is a different story. Engine parameters
may fluctuate, and there may be a noticeable drop in TGT. AFM procedures recommend the
following during flight thru heavy rain/hail:

 Avoid rapid power adjustments

 Airstart Ignition - ON
 Autothrottles - OFF
 Maintain as high a power setting as possible.

In closing, Don relayed a humorous observation from the GIV AFM Appendix E. In what may be a
classic understatement, the AFM says, “If both engines flameout, immediate relight is
recommended.”

ADVERSE OPERATIONS: ELEVATORS INGEST WATER DURING HEAVY

RAIN

With the tropical season here, we highlight the following event as our adverse operations topic. A
GIV operator reported their aircraft had been parked in a monsoon-type rain for several hours,
and their pressing flight schedule required departure during the storm. Shortly after takeoff, the
flight crew noticed that when making pitch/longitudinal changes, it felt as though the gremlin from
the “Twilight Zone” was hanging from the elevators.

After landing at the next destination, the flight engineer began inspecting the longitudinal system.
No abnormalities were noted, but when the crew pulled the control column full aft, water drained
from the elevators. It was surmised that the elevators ingested water during the storm and the
water froze in flight. This created the resistance felt in the control column. There are two drain
holes in each elevator. However, an excessive amount of precipitation may render them
ineffective. Therefore, when the elevators are subjected to heavy rains, we recommend the crew
hold the control column full aft for 10 to 15 seconds just before beginning the takeoff roll. This
should allow entrapped water to drain from the elevators.
(GAC Breakfast Minutes – 07/08/97)

Rainy Weather Affects Tire Performance

During this time of year, we generally see a lot of thunderstorm activity across the country. So
here’s a reminder about rainy weather’s effect on tire performance. A smooth tire may hydroplane
in water depths as little as 0.1 inch. A ribbed tire will release the hydrodynamic pressure and will
not hydroplane until water depth is 0.2 to 0.3 inch. Without measured runway water depths, we
recommend you use the following information to determine the possibility of hydroplaning.

• Light rain reported - Dynamic hydroplaning is unlikely.

• Moderate rain reported - All types of hydroplaning are possible. Smooth tires will likely
hydroplane.
• Heavy rain reported - Hydroplaning will occur.
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We normally think of hydroplaning affecting braking control. However, nose tire hydroplaning will
also reduce nose wheel steering effectiveness and, consequently, the pilot’s ability to cope with
crosswinds.
(GAC Breakfast Minutes – 05/20/97)

INSPECTIONS RECOMMENDED FOLLOWING ACTUAL OR SUSPECTED

LIGHTNING STRIKES

Lightning strikes occur more frequently this time of year. Summertime brings out thunderstorms
and lightning activity. Mark discussed where you can find the information to get your airplane up
and running after a lightning strike and some particular areas to inspect on the aircraft.

When and where can you expect a possible lightning strike? Lightning is very unpredictable by its
nature and can be potentially very damaging to an aircraft. We have heard reports of lightning
strike occurrences at every flight attitude—on climbout to 27,000 ft; on approach; and in clear air
where the aircraft was being vectored well clear of storm cells. We do not completely understand
the nature of lightning. An article titled “Weather on the Web” from the July 1998 issue of AOPA
Pilot magazine reports the discovery of a new form of lightning. Called a sprite, this new lightning
emits from the top of a thunderstorm cloud and goes past the stratosphere (up to about 59 mi./95
km). Sprite lightning was first reported by NASA astronauts on space shuttle missions. As sprite
lightning is so elusive, the photograph shown in AOPA Pilot represents one of the first available
images.

Be Aware of Lightning Occurrences

Lightning is something we have to pay attention to. What should you do when you suspect your
aircraft has incurred a lightning strike? First, you need to be aware of it. There have been reports
where the flight crew was unaware of a lightning strike and the passengers reported it to the flight
crew. There have been situations where nobody aboard the aircraft was aware of the lightning
strike and it was found on the post-flight inspection.

If a lightning strike is suspected, there are certain things the flight crew can do to help out ground
personnel. The crew can annotate the position of the flight controls. Beneficial would be answers
to these questions:
• Were the speed brakes up?
• Were the flaps down?
• Was the landing gear down?
• What were the trim settings?

All of this info will help the maintenance personnel in their inspection of the aircraft. Chapter 5 of
each Gulfstream Aircraft Maintenance Manual outlines inspection procedures following a lightning
strike.

Check Entry and Exit Points

One of the first things we ask you to do is find the lightning entrance and exit points. Exit points
are pretty easy to find and can be identified by discolored paint and by the static wick dischargers
—bases and static wicks themselves—being damaged. The trailing edges may be eroded and
splattered with molten aluminum. There may be pitting at the rivet heads. These are all good
indications of the lightning strike exit point.

The entry point of a lightning strike is a little more difficult to ascertain. Points where lightning
typically enters include: the radome, the forward fuselage area, the nose landing gear door area,
Gulfstream IV Notes 21
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wing tips, and winglets. These are typical points of entry, but by no means are they the exclusive
points of entry. Lightning can enter and exit an aircraft at any point.

Look at Hinge Point Areas

Following the inspection of entry and exit points, the next thing to do is inspect the moveable
surfaces, paying particular attention to the hinge point areas of all flight controls. If there is any
evidence there has been lightning damage at the hinge area, then the associated flight control
must be removed. The bearing and its associated grease path (if any) or the sealing qualities of
the bearing must also be ascertained. If there is any doubt about damage, you should replace
that bearing. Trim tabs and all of the associated linkage going to the trim tabs (push rods, cables,
etc.) need to be inspected. The flaps need inspection. In one reported case, lightning came in
through the radome, migrated down the fuselage and out toward the flaps. It used the four flaps
tracks as a discharge wick, thereby damaging the rollers and flap tracks. The entire flight controls
have to be inspected, especially the trailing edges and any sharp protrusions.

Gulfstream uses the fuselage as the electrical ground for our aircraft. Lightning is lazy; it will take
the path of least resistance and use the fuselage and the fuselage surface coatings. As lightning
moves down the fuselage, it is going to impact certain areas: protrusions on the fuselage;
vulnerable areas, such as static wicks, pitot static tubes, angle-of-attack probes, VHF (or any)
antennae, and the tail NAV light. In one reported case, the steel screws in the NAV light were
impacted on the very tip of the aircraft. The louvers, both by the outflow valves and the vents for
the boiler room, should not be overlooked during inspection.

Look for Paint Discoloration

Chapter 5 of each Gulfstream Aircraft Maintenance Manual points out that if you have paint
discoloration in an area greater than about 2 inches and the temper of the metal is suspected to
have changed, then there are two ways to check for a change in the temper of the metal. The first
is an electrical conductivity test. The second is a Brinell or Rockwell hardness test. The electrical
conductivity test can be done with a portable unit and that is fairly reliable on the thicker
materials. However, if you are using the portable unit on thinner materials, you may want to
administer both tests.

Look for Rivet Damage

As lightning migrates down the fuselage, it will find individual rivets with a lesser degree of
conductivity or more resistivity and the electrical charge will loiter there for less than a second.
This is where and when the damage occurs. Lightning damage is evidenced by spattering of
molten aluminum in and around the countersinks. In this event there are two different repairs. If
the original rivet was a reduced-head (NAS1097) rivet, you may elect to replace it with the same
diameter rivet. The other repair would be to oversize the rivet.

Look at the Landing Gear

It is highly unlikely that the structural integrity of the landing gear will be compromised by a
lightning strike. Likewise, the shock absorbing capacity of the landing gear is seldom
compromised. There are brackets and clamps on the landing gear and grease fitting nipples that
have, on occasion, been burnt off. Take a particular look at these areas as possible discharge
points. For one example, if lightning strikes a bracket that contains a wire bundle, all of the
associated systems affected by the wires within that bundle must be operationally checked. If you
do an operational check and find that the system is working okay, you can assume lightning has
not impacted that system.

A hydraulic line, by contrast, does not make a very good path for lightning conductivity. However,
the bracket for the hydraulic lines can cause thermal shocking and stress to the hydraulic fluid. If
Gulfstream IV Notes 22
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this is suspected, we recommend changing the filters and flushing the hydraulic fluid in that
particular system.

Rolls-Royce Engine Inspections

When your aircraft encounters a lightning strike, you must inspect the engine. The mainstays of
the Gulfstream fleet are the Tay and the Spey engines—they are our most numerous engines.
The requirements for engine inspections can be found in Chapter 5 of the respective Roll-Royce
Manual. Basically, the inspection calls for opening the engine cowlings and inspecting for obvious
lightning strike damage. In the case of the Spey, if damage is obvious, contact the Rolls-Royce
representative and get a disposition on that engine.

For both the Spey and Tay engines, you should inspect the scavenge screen and the magnetic
chip detectors. These inspections are at an interval of 25 hours, for a period of 100 engine hours.
Following that, if metal is not found in either the filters or the chip detectors, you can resume
normal operations and annotate the lightning strike in the engine log.

Editors note: This reference from one reader to another looking for a resource on in-flight
lightning strike probabilities and conditions for occurrence recently appeared within NBAA’s e-
mail forum, Air Mail:
“Try Dennis Newton’s book Severe Weather Flying, second edition.”
(GAC Breakfast Minutes – 7/14/98)

Rolls-Royce Engine Inspections

When your aircraft encounters a lightning strike, you must inspect the engine.
The mainstays of the Gulfstream fleet are the Tay and the Spey engines—they
are our most numerous engines. The requirements for engine inspections can be
found in Chapter 5 of the respective Roll-Royce Manual. Basically, the inspection
calls for opening the engine cowlings and inspecting for obvious lightning strike
damage. In the case of the Spey, if damage is obvious, contact the Rolls-Royce
representative and get a disposition on that engine.

For both the Spey and Tay engines, you should inspect the scavenge screen and
the magnetic chip detectors. These inspections are at an interval of 25 hours, for
a period of 100 engine hours. Following that, if metal is not found in either the
filters or the chip detectors, you can resume normal operations and annotate the
lightning strike in the engine log.

ADVERSE WEATHER - DESERT OPERATION

Desert operation generally means operation in a very hot, dry, dusty, often windy environment. •
Inspection - Under such conditions, sand and dust will usually be found in vital areas of the
airplane. Inspect for sand and fine dust at hinge points, bearings, landing gear struts, and engine
inlets. • Covers - Pay particular attention to inlet, pitot/ static port covers during installation and
removal. It may also be helpful to bring along more covers than by might normally be used for
parking in a non-desert location. Make a checklist of all covers.
Gulfstream IV Notes 23
Revision 2-98 Miscellaneous Information

• Brake Temperature - After landing, avoid excessive use of brakes. During taxi, limit use of
brakes if safe to do so. Idle reverse can be used on clean taxiways. If hard braking is required
during landing, parking brake should not be set until the brake temperature has cooled. Chock the
nose wheel only until the brakes cool. Aircraft with a brake temperature monitoring system
(BTMS) have an advantage here.

• Taxi/Parking - Taxi/position the aircraft so engine blast will not expose other aircraft, personnel,
and ground equipment to blowing sand or dust. Parking: If blowing dust or sand is anticipated,
position aircraft with nose pointed into wind, flaps retracted. Install cockpit sun screens and lower
cabin window shades. If shades cannot be lowered, ensure no cushions or other items are resting
against inner window pane. Manually close outflow valve.

• Cockpit/Cabin Cooling - To achieve better cockpit/cabin cooling, use APU as air source: APU air
“ON” after landing; both engine bleed air switches “OFF.” This will prevent thermal transients
when power levers are moved. Before takeoff, to preclude APU temperature transients and
pressurization surges: Engine bleed air “On”; APU air “OFF”; APU as required.
(GAC Breakfast Minutes – 05/13/97)

Taxiing In Desert Regions - Taxi the airplane to avoid blowing sand or dust on other
airplanes, personnel, or equipment. Use the brakes sparingly to avoid overheating. The use of
reverse thrust may blow sand and dust directly in front of the engine intakes. Avoid taxiing
through sand piles.

Safety Reminder - During spring, storms can pop up suddenly. Maintenance personnel should be
mindful of any objects that may blow away and/or become ingested by running engines. Also,
cowling struts should always be used to support an open cowling. Of particular concern is the
upper engine cowling, which, if not secured, can easily be lifted by a strong gust of wind or
another aircraft’s engine blast.
(GAC Breakfast Minutes – 04/22/97)

RVSM

RVSM Today: An Update

Bob’s update is a snapshot of where we are with Reduced Vertical Separation Minimums, the
ICAO-member program to reduce vertical separation between aircraft in the North Atlantic Tracks
from 2,000 ft. to 1,000 ft. between Flight Levels 290 to 410. Workshop - A thorough RVSM update
will be given by Darwin Stout at the 1997 Workshop in the maintenance and pilots sessions. For
those of you who will not be at Workshop, contact Bob at 912-965-3400 for a copy of the package
we intend to present. RVSM 101 - Back-to-Basics • Standard separation in Minimum Navigation
Performance Specification (MNPS) Airspace is:

- 2,000 feet vertically

- 10 minutes longitudinally (in-trail, based on Mach number)
- 60 nautical miles horizontally (track separation)

• RVSM Airspace addresses only vertical separation of 1,000 ft. Bob hinted that a couple of other
programs are coming to address the nose-to-tail and horizontal separation.
• Current RVSM Phase

- Started March 27, 1997

- Reduces vertical separation to 1,000 ft. for Flight Levels 330 to 370
Gulfstream IV Notes 24
Revision 2-98 Miscellaneous Information

- In effect for at least 9 months - through 1997; At the end of the year, the ICAO decision-making
group will determine if additional capacity is needed.
- Full implementation from FL290 to FL410, as is ultimately planned, will increase North Atlantic
Track traffic capacity about 85%. There is some question right now if that capacity is truly
needed.

Current RVSM Situation

• Gulfstream aircraft can get above RVSM airspace with very little trouble. In almost every case,
they are able to climb above. However, most operators are being questioned if they are RVSM
capable when they check in with oceanic control to get clearances. “This makes everybody
nervous,” Bob said. We truly expected to have the RVSM situation resolved by now. However, we
are closing in on it fast. We have meetings with the FAA scheduled soon and hope to announce
by Workshop that we are well on our way to getting the Gulfstream fleet RVSM qualified.

• GII aircraft coming out of Shannon, Ireland, with heavy loads on hot days with strong head
winds may require extra planning to ensure they can get above RVSM airspace.

• Aircraft are being cleared to climb (continuously) or descend through RVSM airspace, traffic
permitting. For now, RVSM is not causing significant problems for the Gulfstream fleet. However,
that may change if the altitudes are expanded to FL410.

(GAC Breakfast Minutes – 05/20/97)

Q - What Minimum Equipment List (MEL) items will be impacted by RVSM?

A - The respective AFM Supplement for each RVSM ASC (GIV ASC 380, GIII ASC 308, GII ASC
498/499) lists the Master Minimum Equipment List (MMEL) items affected by this program. For
the GIV, the required items are: Flight Guidance Computer - the aircraft must have an operating
autopilot; one transponder; and both Air Data Computers (ADCs). We are also modifying the
respective MMELs to reflect what items are required for flight into RVSM airspace. This will allow
operators to either modify their MEL or adopt the Gulfstream MMEL.
We have submitted the GIV MMEL changes for FAA approval. Although the MMEL changes may
not be in effect at first, the FAA feels that the AFM supplement will adequately cover the items
required for RVSM operation.

(GAC Breakfast Minutes – 08/05/97)

RVSM Certification and Implementation

As promised last week, today’s Reduced Vertical Separation Minimums (RVSM) update
includes a detailed overview of GIV Aircraft Service Change (ASC) 380 implementation
and customer procedures.

RVSM Update GIV Federal Aviation Administration (FAA) RVSM approval on August
8, 1997, triggered several actions: • Release of GIV ASC 380 • GIV Airplane Flight
Manual Supplement GIV-97-02 • GIV Operator’s Data Package, which includes:
Information and application for Letter of Authorization (LOA); Details on monitoring
flights. Technical Update This material was mailed to all GIV operators last week. If you
have not received yours, it should arrive shortly. We have incorporated ASC 380 on
several aircraft and begun the corresponding GPS Monitoring Unit (GMU) monitoring
flights. Bob said, “ASC 380 is off and running, and the RVSM program as well.” A
future update will cover the GII and GIII RVSM programs in detail. We feel that GIV
Gulfstream IV Notes 25
Revision 2-98 Miscellaneous Information

RVSM certification paves the way for GIII then GII certification. We will work hard to
get those programs approved and to you operators as soon as we can.

Flight Manual Supplement GIV-97-02

This supplement contains valuable RVSM information needed to both operate the aircraft in
RVSM airspace and submit an application to the FAA/aviation authority for an LOA. • RVSM
Flight Envelope - This is virtually the entire GIV cruise envelope, so we did not have to accept
limitations to meet the RVSM requirements: .61 to .88 Mach; FL 290 to FL 410; 40,000 to 75,000
lb. • RVSM Dispatch Capability - The ASC lists the required items for RVSM operation. The GIV
is equipped with two of each component required for RVSM. In most cases, at least one must be
working. • Normal Procedures - Left and right static port inspection procedures were added to
Exterior Preflight • Abnormal Procedures - Loss of equipment procedures were added to
Abnormal Procedures. All of this information will help you present your data to the FAA or aviation
authority.

Bob introduced Darwin Stout, Service Center RVSM Coordinator, to complete today’s briefing.

Three steps to RVSM certification Darwin began by saying there are three steps to getting RVSM
certification: • Incorporate ASC 380 (or respective ASC) • Submit an operator’s data package to
your local Flight Standards District Office (FSDO) or aviation authority • Complete a monitoring
flight.

RVSM ASC 380 This was released August 11, 1997. “We appreciate your patience waiting for
this,” Darwin said. Highlights are: • Visual inspection around primary (upper) static port • RVSM
check of air data system - For an extra $350 we will do the entire FAR 91.411 and 91.413 checks
to keep all dates in synch • $14,000 domestic, $15,120 international - two days downtime We
have done ten ASCs and completed one GMU flight.

Static Port Skin Inspection We worked diligently to convince the FAA that skin mapping would not
be needed. This is partly why GIV approval took so long. • No skin mapping required • 4-inch
radius around primary static port • Skin waviness checked • Few simple measurements - using
straight edge and feeler gauge • Only problem (minor) so far has been sealant voids • Paint
thickness in the 4-in. radius can be a factor - Paint thickness of 12 mils (0.012) or less is okay
with or without stripes. Gulfstream Aerospace Materials and Process Specification (GAMPS)
4000 exterior paint preparation/procedure is being updated to match ASC 380’s requirement for
new paint jobs.

Pitot Static System Testing • More accurate air data test set - Only required for biannual checks
or recalibration on the aircraft; Not required if the Air Data Computer (ADC) was bench checked
by a Honeywell-approved facility • Normal two-year test interval remains in effect.

Authorized RVSM Facilities • Gulfstream Service Centers in Savannah, Brunswick, Long Beach -
training program complete • Gulfstream Authorized Service Centers and Warranty Repair
Facilities - training program underway Chrysler Pentastar (Detroit) - up and running Marshall
Aerospace (Cambridge) - up and running Jet Aviation (Basel) - up and running Jet Aviation
(Geneva) - working to get training in place Associated Airlines (Australia) - working to get training
in place Jet Maintenance (Singapore) - working to get training in place We will let you know via
Breakfast Minutes when the last three facilities are ready.

Operator’s Data Package A sample data package was completed and shipped to all GIV
operators on diskette and paper copy. The package has two sections: The Information Section up
front is good reference material; The Submittal Section is for getting RVSM approval for your
operation. Simply fill in the blanks, print, and submit to your local authority. Although we made the
form as generic as we could, it may require customization to gain your local authority’s approval.
Gulfstream IV Notes 26
Revision 2-98 Miscellaneous Information

Darwin emphasized that you should not submit the paperwork without reading and understanding
what you are committing yourself to!

Monitoring Flights There are two ways to complete the required RVSM monitoring flight: • Height
Measuring Unit (HMU) Flights - These can be made over a facility in Strumble, England. Refer to
Operator’s Data Package Reference Document 5, Information Section for details. • GMU Flights -
ARINC in Annapolis, Maryland, is in charge of GMU flights. We have two GMUs in the Savannah
Service Center. GMU monitoring flights are at no charge except for crew and fuel. We provide the
form to arrange the GMU flight. Part of the form requires the name of your FAA/aviation official so
ARINC can contact them to ensure you are approved for RVSM flight. It is important to talk to
your FSDO/authority to get their concurrence to do the flight after ASC incorporation. GMU flight
can be done after your local authority gives approval. The aircraft must fly straight and level at or
above FL290 for 30 minutes to get readings. The data is sent via diskette to ARINC for
processing. Expect the process to take a couple of weeks before you get the results. Contact Bob
Miller at ARINC (410-266-4891) for GMU flight information.

Any More Questions? If you have any questions about RVSM, here is the revised contact list: •
Darwin Stout, Service Center RVSM Sales/Info phone: 912-965-5677 • Jack Barnett, Service
Center Scheduling phone: 912-965-5995 • Bob Morris, RVSM Program Manager phone: 912-965-
3400 • Ric Norton, RVSM Project Engineer phone: 912-965-3489.

(GAC Breakfast Minutes – 08/19/97)

Expanded RVSM Flight Levels are Delayed from 1st Q 1998 to 4th Q 1998

On October 8, 1998, the Reduced Vertical Separation Minimums (RVSM) will expand to both
higher and lower levels, to encompass 31,000 ft (FL310) through 39,000 ft (FL390). Until then,
altitudes for RVSM in the North Atlantic (NAT) remain at FL310 through 370.

RVSM will eventually take the entire NAT airspace. Compliance is expected to follow in the
Western Atlantic Regions (WATRS), which means those operators flying in the Caribbean will be
the next to comply.

The growth schedule calls for full European implementation around the year 2001, with
compliance in the Pacific Ocean Region (PAC) to follow closely thereafter.

What this all means is that in the very near future, any production aircraft capable of flying above
FL290 will have to be compliant to RVSM specifications as set forth in Interim Guidance on
Aircraft and Operator Approval for RVSM Operations Above FL290.
(GAC Breakfast Minutes – (01/20/98 )

RVSM Update

Mike Rowland, RVSM Program Manager, gave an update on Reduced Vertical Separation
Minimums (RVSM). RVSM is an International Civil Aviation Organization (ICAO) sponsored
program that reduces the vertical separation minimums (VSM) from 2,000 to 1,000 ft at
designated flight levels in the North Atlantic (NAT) Region Minimum Navigation Performance
Specification (MNPS) airspace.

ICAO’s Latest Schedule

· Phase 1 - RVSM was initiated on March 27, 1997, for Flight Levels 330-370 in the North
Atlantic tracts.
· Phase 2 - The scheduled altitude expansion on October 8, 1998, will include Flight Levels
310-390.
Gulfstream IV Notes 27
Revision 2-98 Miscellaneous Information

· Full RVSM Airspace - The expansion to full RVSM airspace, Flight Levels 290-410, has
not been scheduled at this time. The expansion of RVSM beyond the North Atlantic tracts
has also not been scheduled. The feeling is the next area expansion will be into the
Western Atlantic region, but that is probably at least two years away.

RVSM Phase Conditions

· Phase 1 - Gulfstream II, IIB, III, IV, and V aircraft should be able to get above RVSM
airspace both westbound and eastbound. Hot days, strong headwinds, or heavy loads
may require extra planning. You are able to transit through RVSM airspace traffic
permitting.
· Phase 2 - GIIBs, GIIIs, GIVs, and GVs can get above RVSM airspace. However, GIIs,
particularly westbound, will have difficulties, and this will be the first real operational
impact to the Gulfstream fleet. You are able to transit through RVSM airspace traffic
permitting.

HMU Status

Mike briefly covered the status of the two Height Monitoring Unit (HMU) locations.

· Strumble - The HMU that has operated for some time at Strumble (United Kingdom) has
been down for maintenance. It is scheduled to come back on line in April.
· Gander - The new HMU facility in Gander is scheduled to be on line in July.

ASCs and Pricing

Specific ASCs for the various Gulfstream models were covered next.

TYPE / AP S/Ns ASC AVAILABILITY PRICE (K)

GV 501-529 Except 503 5 Released $ NC

ALL 13 6/19/98 $ NC

GIV ALL 380 Released $ 14

ALL 380AM1 2Q98 $ 14

(GAC Breakfast Minutes -- 02/24/98)

Getting Approval for RNP-5 and RNP-10 Operations

Chuck discussed two closely related items: Required Navigation Performance 5 (RNP-5),
sometimes called Basic Area Navigation (BRNAV), and RNP-10. RNP-5 pertains to European
airspace; RNP-10 pertains, at this time, to six or seven routes in the Northern Pacific (NOPAC)
and Central East Pacific (CEP) regions. RNP-5 and RNP-10 are slated for effectivity on April 23,
1998. (Note: The procedures in this article are for U.S.-registered aircraft. Foreign-registered
aircraft will have to coordinate RNP approval through their governing airworthiness authority.)

RNP-5 -- Essentially, RNP-5 means that your onboard navigational systems -- INUs, and IRUs, in
conjunction with VORs, DMEs, Loran, if so equipped, or GPSs -- have to maintain a deviation
from assumed position of no greater than five nautical miles in any direction for 95% of the flight
time above 9,500 feet. The rationale of this is similar to RVSM, in that it affords you greater
Gulfstream IV Notes 28
Revision 2-98 Miscellaneous Information

flexibility in flight planning, increased fuel savings, and reduced dependency on ground-based
point source navigational aids.

Gulfstream IVs and Gulfstream Vs, on the basis of the equipment installed in production, are
already approved for RNP-5 operation. You will find that information in your AFM. Because of the
vast array of navigational configurations installed by the outfitters, Gulfstream IIs and Gulfstream
IIIs will have to be addressed on a one-for-one basis.

To determine if your aircraft is approved for RNP-5 operation, look in your airplane flight manual
(AFM) or your AFM supplements for reference to the following FAA Advisory Circulars: AC 90-
45A, AC 20-130, AC 20-130A, AC 20-138, or AC 25-15. If specific reference to these Advisory
Circulars and a corresponding RNP value of five or less is made and you are a Part 91 operator,
no further documentation is required.

For Part 121, 125, and 135 operator, the process is a bit more complex. If your AFM reflects the
above Advisory Circulars and a corresponding RNP value, your aircraft is approved for operation.
However, you must submit the proof of installation, in accordance with the Advisory Circulars, to
your Certificate-Holding District Office (CHDO) to have your operational specifications updated to
reflect that approval. If your AFM does not display compliance with the respective Advisory
Circulars, approval for RNP-5 operations can be obtained by submitting evidence of your
equipment meeting the requirements to your local Flight Standards District Office (FSDO), for
assessment of eligibility, or you can forward your request and the supporting documentation to
your Regional Flight Standards Service, Tech Programs Division for review.

RNP-10 - RNP-10, similar to RNP-5, is a requirement for navigational accuracy that currently
affects only six or seven routes in the Pacific region. It is slated for expansion into all dense
Pacific airspace by 2000. The RNP requirements are intended for oceanic and remote areas
where aircraft separations are on the order of 50 nautical miles. This can be further defined as
maintaining both track and positional accuracy of plus or minus 10 nautical miles for 95% of the
flight time in RNP-10 airspace. As was the case with RNP-5, the GIVs and the GVs are approved
for RNP-10 operation on the basis of the production equipment that was installed. This
information has been inserted into the AFM and will be posted with the next revision. GIIs and
GIIIs will have to be addressed on a one-for-one basis.

RNP-10 authorization is a two-step process. First, each aircraft must be determined to be

qualified. Secondly, each individual operator must be approved by the appropriate FAA offices
before that operator can conduct operations in RNP-10 airspace. Part 91 operators will require a
Letter of Authorization (LOA) after successfully completing the requirements. Part 121, 125, and
135 operators will be issued an approved operational specification once the requirements are met
supporting RNP-10 operations.

For RNP-10 authorization, first contact the FAA and obtain a copy of FAA Order 8400.12A,
“Required Navigation Performance 10 (RNP-10) Operational Approval.” It contains complete
guidelines to walk you through the application procedure, as well as a generic application.
Paperwork required for RNP-10 operations is dictated by the FARs you operate under. Secondly,
schedule a meeting with your FSDO (for Part 91) or CHDO (Parts 121, 125 and 135) and advise
them of your intent to apply for RNP-10 ops.

The RNP-10 applications, regardless of FAR operations, must contain the following:

• Your eligibility and airworthiness documents

• A description of your navigational equipment and accuracy factors
• RNP-10 time limits for inertial reference and inertial navigation systems
• A summary of your operational training programs, practices, and procedures
• Supplements to your operational manuals
Gulfstream IV Notes 29
Revision 2-98 Miscellaneous Information

• A copy of your checklist amendments and solutions dealing with any item that could possibly be
Minimum Equipment List (MEL) related, e.g., triple blending.
• A proposed maintenance program
• History of Class II navigational performance.

If you have any questions concerning the accuracy factors of your long-range navigational
systems, start with your outfitting agency. Also, contact the equipment manufacturers. Any letter
of accuracy and reliability must come from that manufacturer. Lastly, we here at Gulfstream have
been working closely with the folks at Honeywell, Litton, Delco, Universal, and AlliedSignal to
ensure that the required support data will be available.

Call Technical Operations for additional support and guidance: Chuck Domras 912-965-4859;
Chris Remion 912-965-3692. You can also visit the FAA web site at www.faa.gov and the NBAA
web site at www.nbaa.org for more information. Search both sites on the keyword “RNP” and you
will find reference information.
(GAC Breakfast Minutes –(02/10/98 )

BRNAV

BRNAV Coming to Europe in 1998 - The NBAA web site has a variety of information on Basic
Area
Navigation (BRNAV)/Required Navigation Performance Type 5 (RNP-5), a program coming to
European Class I airspace in early 1998. A draft copy of FAA Advisory Circular 90-BRNAV is also
available for review, as is JAA Temporary Guidance Leaflet No. 2 Rev. 1.

Please visit http://www.nbaa.org/member/airport/rnp/brnav.htm for more information.

(GAC Service News -- 4/97)

JAA Leaflet Has Basic RNAV Guidance

With the release of the Joint Aviation Authority (JAA) Temporary Guidance Leaflet No. 2 revision
1, an operator asked Gulfstream whether the production GIV still met basic area navigation
(RNAV) requirements for Europe. Besides providing guidance material for airworthiness approval
and operational criteria for basic RNAV in European airspace, the JAA document also contains
guidance material for using stand-alone Global Positioning System (GPS) equipment for these
operations. The document’s reference to GPS equipment that is not a standard production
installation may have caused a few operators to think that it may now be a requirement. The JAA
leaflet considers existing airworthiness approval standards as providing acceptable means of
compliance. The following FAA Advisory Circulars are listed within the related navigation
documents and are acceptable for basic RNAV operations: AC 90-45A, AC 20-130, AC 20-138,
and AC 25-15. The GIV AFM notes, which appear on page 5-17 for the SPZ-8000 FMS and on
page 5-24K for the SPZ-8400 FMS, state: “Provided the Flight Management System (FMS) is
receiving suitable navigation information from at least one (1) VHF Omni Range/Distance
Measuring Equipment (VOR/DME) or two (2) DMEs, it is approved as an area navigation system
for enroute, terminal, and approach operations in accordance with FAA Advisory Circular No. 20-
130.” As described in the GIV AFM note, the GIV production aircraft comply with basic
requirements and no further documentation is required. Similar wording will be added to the GV
AFM for basic RNAV, and both the GIV AFM and GV AFM will have wording added to address
using GPS. Due to the variety of equipment that exists on GII and GIII aircraft, these operators
will have to handle approvals on an individual basis. We feel that most will meet the requirement
if they have either an Inertial Navigation System (INS) or RNAV that has update capability.
(GAC Breakfast Minutes – 09/23/97)
Gulfstream IV Notes 30
Revision 2-98 Miscellaneous Information
Gulfstream IV Notes 1
Revision 2-98 ASC List

20. ASC LIST

A PARTIAL LIST OF AIRCRAFT SERVICE CHANGES OF

OPERATIONAL INTEREST TO PILOTS

ASC 1: Wing Tip Flood Light Installation

PURPOSE: Will assist the pilot and crew in determining wing tip position in relation
to other aircraft and objects while taxing at night.

ASC 10: Hi Intensity Anti-Collision Light Installation

PURPOSE: Replaces the bottom rotating anti-collision beacon with an electronic

strobe type beacon. This new strobe type beacon has no moving parts and
will provide a significant improvement both in visibility and service life.

ASC 13: APU starter drop-out light

PURPOSE: Starter light extinguishes only when power removed from starter motor
instead of a set RPM.

ASC 49A: Cockpit display unit & nose compartment fans replacement

PURPOSE: This ASC replaces the AC powered DU and nose cooling fans with DC
powered fans (quieter).

ASC 50: Increase area outflow valve louver.

PURPOSE: This ASC replaces the present outflow valve louver with an improved
louver.

ASC 54: Battery Charger and Control Improvement

PURPOSE: Provides individual control of the battery chargers. Currently a single c/b
controls both Battery Chargers. If it pops -- both battery chargers are lost.
This modification provides separate control circuits (and c/C/B’s) for each
battery charger, allowing independent operation.
Gulfstream IV Notes 2
Revision 2-98 ASC List

ASC 61: Increased Zero Fuel Weight

PURPOSE: Increases Zero Fuel Weight from 46,500# to 49,000#. No increase in

maximum gross takeoff weight. Lose about 500 NM range using the
increased maximum zero fuel weight takeoff. Mostly used by the Saudis
and Kuwaitis due to heavy aircraft outfitting.

ASC 69: Flap Asymmetry Indication System

PURPOSE: This ASC installs a flap asymmetry indicator light in the cockpit. When
the flap asymmetry switches sense a mismatch in flap position, the flap
control relay will be de-energized causing the indicator light to come on.
This will indicate that the flaps have stopped due to an asymmetry
condition. As long as flaps stay symmetric, this system will not be
activated due to an hydraulic or mechanical malfunction.

ASC 98: Electrical Bus Energized Alert

PURPOSE: Provides visual and aural alert to crews to prevent inadvertent aircraft
battery discharge. Also relocates the aft outside battery switch to the
forward external switch panel.

ASC 102: Cat II Certification

PURPOSE: Activates annunciation for Cat II approaches.

ASC 112: 300 Amp Transformer-Rectifier with Increase Voltage Capability

PURPOSE: This ASC replaces the existing TRU with a unit capable of maintaining a
higher output voltage under load.

ASC 118: Landing "G" Meter installation

PURPOSE: This ASC installs a Landing "G" Meter that senses and records landing
force for use with overweight landings to determine the amount of
inspection needed.

ASC 119: APU Shutdown Modification

PURPOSE: This ASC modifies the circuitry to ensure that placing the APU master
switch OFF will shut down the APU starter.
Gulfstream IV Notes 3
Revision 2-98 ASC List

ASC 126: Windshield Heat Controller Reset

PURPOSE: This ASC eliminates possible windshield damage due to a windshield heat
controller malfunction.

ASC 129: AOA Reset Relay

PURPOSE: Provides automatic reset after test instead of manual reset by the AOA test
button. AOA Reset Relay is scheduled for cut-in at GIV S/N 1310.

ASC 131: Taxi Light Positive Control Modification

PURPOSE: This ASC ensures the taxi light will go off anytime the landing gear is not
in the down and locked position.

ASC 135: ECS Pack Sequencing During Engine Start

PURPOSE: This ASC rewires the air conditioning system so that the ECS pack
shutdown is staggered -- Left Pack OFF when Start Master selected ON,
Right Pack OFF when Starter Switch is pushed.

ASC 151: Engine Ignition Ground Start ON Single Plug

PURPOSE: This ASC improves the service life of the inboard engine igniter plug by
using it only for air starts. Not too popular, causes torching starts. Being
removed by some operators.

ASC 157: Smoke Evacuation Valve Installation -- Baggage Compartment

PURPOSE: This ASC installs a system designed to assist in smoke and fume
evacuation from the baggage compartment, aft lavatory and galley areas.

ASC 163: ICS Switch Replacement

PURPOSE: This ASC replaces the ICS switch on the pilot's and copilot's control
wheel with a new spring-loaded switch.
Gulfstream IV Notes 4
Revision 2-98 ASC List

ASC 166: Thrust Reverser Secondary Lock Timer and Wheel Spin up Modification

PURPOSE: This ASC adds additional circuitry to the thrust reverser system to
increase reliability. Allows faster deployment of the reversers and
eliminates the one minute limitation. An amendment is due in the first
quarter of 1995 to fix a spin-up logic flaw in the ASC 166 modified
system. Landing with the T/R levers moved to the interlock position can
cause reversers to deploy with single wheel spin-up, resulting in a hard
landing. And it is possible, using this technique for reversers to deploy in
flight with a single-point failure of the deployment circuitry.

ASC 167: Brake Temperature Monitoring System (BTMS)

PURPOSE: Installs the BTMS in earlier aircraft.

ASC 170: Cockpit/Cabin Temperature Sensor Power Source -- Re-Bus

PURPOSE: This ASC allows temperature control of the cockpit and cabin from the
essential 28v DC Bus.

ASC 176: Nose Wheel Steering Fail Annunciation

PURPOSE: "Steer By Wire Fail" annunciator currently indicates loss of elect power to
steering ECU only. This ASC changes to indicate that plus loss of
hydraulic steering pressure on ground, applied steering pressure in flight
and steering turned OFF.

ASC 178: Electronic Checklist Installation

PURPOSE: This ASC installs an electronic checklist in EICAS

ASC 190: Weight Increase to a GIV SP equivalent, heavier gear & Dunlop brake-by-
wire brakes, wheels & tires

PURPOSE: Increases Zero Fuel Weight from 46,500# to 49,000#, Max Gross Weight
to 75,000#, Installs Dunlop brake-by-wire brakes and heavier gear. With
addition of ASC 307, brings aircraft to GIV SP status. Dunlop Brake-By-
Wire System considered very good. ASC 307 (hydro-mechanical brakes)
not considered necessary.

ASC 198: ACM Bypass Shutoff Valve-Activation

PURPOSE: This prevents the cooling turbine hot message on the EICAS from
annunciating when the A/C is below 42,000 feet and wing or Cowl Anti-
Ice is selected.

ASC 210: Thrust Rev Emerg Stow - Power Separation

Gulfstream IV Notes 5
Revision 2-98 ASC List

PURPOSE: This ASC provides separate power sources for the Left & Right T/R
selector in the emergency stow operation. Presently, a single fault in the
system could cause both selector valves to be inoperative.

ASC 212: APU Start Contactor Replacement

PURPOSE: This ASC provides an immediate indication to the cockpit should the APU
Start Contactor fail to open at the end of the APU start cycle

ASC 214: Transponder Cross Source Selector Enabled

PURPOSE: This ASC allows transponder to use cross side DADC altitude output for
Mode C

ASC 220: Engine Centrifugal Oil Breather Outlet Tube Modification

PURPOSE: This ASC prevents oil vapors being discharged to the atmosphere by the
engine centrifugal oil breather outlet tube from staining aft cowling.

ASC 221: Installs FMS/SPZ-8000 Maintenance Test Switch

PURPOSE: A switch in the cockpit for the FMS/SPZ-8000 maintenance test function.
The switch will allow the crew to access SPZ-8000 flight fault summary
fault codes during taxi to the ramp.

ASC 231A: E-Bus Alternate Power Modification

PURPOSE: This ASC provides the E-Bus an alternate source of power to prevent loss
of critical systems in the event an E-Batt fails during normal operations.

ASC 238: Hydraulic Indication Modification

PURPOSE: This ASC corrects hydraulic indication errors after Phase 2 is
incorporated.

ASC 239: Installs Dual Control Windshield Heat Switches

PURPOSE: Currently a failure in the single control switch can cause a failure of both
windshields and side windows. Provides independent control for the Left
and right windshield and side window heating systems.

ASC 240: EICAS On Standby Electrical Power System Modification

PURPOSE: This ASC provides the option of the EICAS DU compacting when
operating on Standby Electrical Power System. Currently DU #4 is
Gulfstream IV Notes 6
Revision 2-98 ASC List

automatically top compacted when Standby Electrical Power System is

activated and cannot be uncompacted to check items unique to the DU-4
display such as hydraulic reservoir quantity.

ASC 243: Nose Cowl Anti-Ice Pressure Warning Switch - Replacement

PURPOSE: This ASC replaces the engine nose Cowl Anti-Ice pressure switches to
eliminate false Anti-Ice warning messages when engines are at flight idle.

ASC 255: This ASC allows an operator to select a recording at any time it is desired.
PURPOSE: Installs a button in the cockpit that causes the FWC to take a snapshot of aircraft
parameters. It is a production standard for aircraft 1253 and subsequent.

ASC 260: Nose Wheel Steering Enhancement

PURPOSE: Beefed up hydraulics and steering ECU modification. Only being

incorporated on aircraft with problem steering if other individual fixes do
not solve problem. 300 man-hours/7-8 days. Increases tiller bar turn to
270 for 80 of nosewheel rotation -- currently 90 tiller rotation for 80 of
nosewheel. Flow restricters to spoilers. No charge if already have ASC
176.

ASC 261: Zero Fuel Gross Weight Increase to 49,000#

PURPOSE: This ASC combined with ASC 350 (max gross weight increase) brings the
GIV to ASC 190 (increased gross weight) level. It permits the operator to
break up the downtime and cost into more manageable portions.
$400,000/5 weeks.

ASC 264: Engine Bypass Drain Modification

PURPOSE: Routes the drain in the aft cowl interface ring overboard. The existing
drain is an open hole vented into the engine cowl area. The new drain will
route the vent overboard to prevent contamination of the under cowl area.

ASC 266: Dunlop Brake by Wire Wheels/Brakes/Tires

PURPOSE: Provides an improved brake-by-wire system. Requires larger wheels (2")

& low profile tires to accommodate the larger brakes. “GIV IP”. Reduces
actual stopping distance by 400' due to larger brake capacity. Includes a
new performance computer that gives credit for auto ground spoiler
deployment shortening landing distances further.

ASC 280: Windshield Heat Transient Voltage

Gulfstream IV Notes 7
Revision 2-98 ASC List

PURPOSE: Adds voltage suppression devices to prevent precipitation caused static

charge build-up transients from entering electrical systems.

ASC 285: Converter Fan Failed Output Latch

PURPOSE: Adds a manually resettable latch circuit that will ensure the failed fan
indication will remain on until the problem is investigated and repaired.
This will be done by adding a latch circuit to the fan failed output.

ASC 288: LP Cooling Air Outlet Gaskets

PURPOSE: Also known as “Soft Seal” mod. Designed to eliminate oil on the GIV
cowlings in conjunction with ASC 264 (Engine By-Pass Duct Drain
Mod).

ASC 295: Relay Switches Pressurization Control to Manual If Power Is Lost

PURPOSE: Presently, if electrical power is lost, the manual mode of pressurization

control must be hard selected. This ASC installs a relay which
automatically switches the cabin air pressure control to manual operation
in the event 115VAC power is lost.

ASC 296: A Three Part ASC for ABS Brake-By-Wire Enhancement

PURPOSE: Improves pedal curve, brake clamp-up characteristics, taxi performance

and provides wheel spindown failure annunciation. Part III is the brake
electronic control unit software upgrade.

ASC 298: Modifies Bleed Air Isolation Valve Power Source

PURPOSE: A problem with the isolation shutoff valve indicating open when it is
actually closed first appeared in 1991. A defective 40 PSI valve on the
subject aircraft had popped the right bleed air circuit breaker. The isolation
shutoff valve indication logic is controlled through the right bleed air
circuit breaker. When the C/B pops, a relay relaxes and annunciates the
isolation valve as being open.

As a result of this condition, Aircraft Service Change 298 was developed

to add an AC valve control relay. This precludes de-energizing of the relay
and a false cockpit indication of valve position.

ASC 302: Rudder Pedal Steering Switch

PURPOSE: Allows rudder pedal steering to be turned off. The switch is housed in its
own control panel which is located just aft of the tiller wheel. There is a
small blue indicator light located near the tiller wheel showing that rudder
pedal steering has been disconnected.
Gulfstream IV Notes 8
Revision 2-98 ASC List

ASC 304: New igniter box with bigger heat sinks.

PURPOSE: Removes Airstart Time Limit. Old box heated up excessively causing
time restriction. Plugs still fail prematurely when used continuously.

ASC 306: Installation of Ground Service Valve Cover

PURPOSE: The cover will limit access to the ground service valve, located in the
right-hand nose wheel well area, to anyone standing in the nose wheel
well. Avoid being caught by the nose gear doors.

ASC 307: Dunlop Hydro-Mechanical Analog Brakes, Wheels & Tires

PURPOSE: Replaces existing brake system with the Dunlop hydro-mechanical brake
system. With completion of ASC 190, brings baseline GIV to SP
standard. 4200 man-hours to complete. Not considered a cost effective
addition to ASC 190.

ASC 313: Cabin Pressurization Stabilization

PURPOSE: Provides sufficient bleed air pressure during low power descents to
maintain cabin pressurization. 12th stage air is selected electrically when
the power lever angle is reduced below 62 degrees. This allows
compensating 12th stage air before engine power is reduced enough to
cause a pressure sag. Bleed air pressure regulation is increased from 18 to
30 PSI.

ASC 314: Auto Ground Spoilers Factored into Landing Distances

PURPOSE: Allows landing distance credit for auto ground spoiler deployment.
Involves new performance charts and a new performance computer. Good
for baseline GIV. "GIV AS" (Auto Spoilers)

ASC 320: Aspen ASC for SP/ASC 190 Aircraft

PURPOSE: Enhanced landing weight aircraft must currently use Category D for
approaches. ASC installs placard permitting Category C approaches if
landing weight not greater than standard 58,500#.

ASC 327: Places the blue annunciator message "SENSOR DC BUS ON BATT" on
the CAS display.

PURPOSE: This ASC provides an immediate indication to the pilots that the Essential
DC Bus is being powered by the Battery Tie Bus (batteries and battery
chargers) and may be draining the batteries. No charge.
Gulfstream IV Notes 9
Revision 2-98 ASC List

ASC 345: SPZ-8400 conversion.

PURPOSE: Upgrades the SPZ-8000 baseline EFIS system to the SPZ-8400 System
with many system enhancements to automate the flying of the aircraft.
Involves a complete rewiring of the aircraft. 1000 man-hours/$1,000,000.

ASC 349: NZ-2000 conversion.

PURPOSE: Converts the NZ-800 series FMS to the NZ-2000 System. Includes a new
lighter, faster (Intel 386 based) processor, and memory increase from 1.2
megabytes to 4 megabytes. Allows the execution of GPS based ap-
proaches..

ASC 350: Maximum Gross Weight Increase to 75,000#

PURPOSE: Combines with ASC 261 to make the equivalent of ASC 190 (increased
gross weight) for operators who want to split the cost and downtime into
more manageable portions. $475,000/4 weeks.

ASC 351: A placard to limit Zero Fuel Weight to 48,000 pounds from the default
49,000 pounds of SP's and ASC-61 aircraft.

PURPOSE: This ASC benefits Part 91 operators that have a payload capability of over
6,000 pounds (a Basic Operating Weight below 43,000 pounds). BOW's
of over 6,000 pounds require operation under FAR Part 125. By legally
restricting operations to 48,000 pounds ZFW, Part 91 regulations apply.
Fleet average BOW's average 43,900 with some topping 45,000 (shower
installations).

ASC 359: Right Bleed Air Bus Change

PURPOSE: Presently the left and right Bleed Air systems and the left and right Air
Conditioning systems are powered from the Essential 28VDC bus. This
ASC will relocate the right Bleed Air, right Bleed Air Indicator and the
right Air Conditioning circuit breakers from the Essential 28 VDC bus to
the right Main 28 VDC bus. This change will provide 28 VDC power for
cabin pressurization from either the right Main 28 VDC bus or the
Essential 28 VDC bus.

ASC 364: 12th Stage Bleed Air Source for Door Seal System

PURPOSE: Improves the cabin and baggage door seal performance and reliability by
providing increased air pressure.
Gulfstream IV Notes 10
Revision 2-98 ASC List

ASC 381: Main wheel well heat

PURPOSE: Changes the plumbing of the wing anti-ice bleed exhaust duct to increase
warming air flow to the wheel well area for brake warming. . (Due 2nd
Qtr. ’97.)

ASC 390: APU Enhancement

PURPOSE: Part 1 – New Cooling Duct

Part 2 – Exhaust Deflector
Part 3 – Improved Venturi
Gulfstream IV Notes I-1
Revision 2-98 Index

INDEX

"ALT"..............................................................................16-61 AFM Appendix E......................................................19-8

"AT".................................................................................16-62
Deicing Operations.................................................19-11
"ATT"..............................................................................16-61
"BRAKE FAIL"..................................................................1-7 Desert Operations...................................................19-22
"BRAKE PEDAL"..............................................................1-7 Heavy Rain................................................................19-19
"CHECK POS SENSOR"................................................16-16 Heavy Rain Operations..........................................19-19
"CHK PFD".....................................................................16-62 Hydroplaning.............................................................19-19
"COOL TURB HOT"........................................................11-2 Lightning Strikes.......................................................19-20
"COWL ANTI-ICE"..........................................................10-1 Air Conditioning................................................................11-1
"DEGRAD".....................................................................16-25 Airconditioning
"DU 4".............................................................................16-61 "COOL TURB HOT"..................................................11-2
"ENG FIRE LOOP ALRT".................................................8-1 Cabin Temperature Control.........................................11-2
"ENG"..............................................................................16-61 Manual Temperature Control......................................11-1
"Engine Hot"................................................................4-4, 8-1 Misting Out Of ACU Exhaust Ducts...........................11-1
"EPMP POWER FAIL".....................................................2-21 Temperature Controls On Essential Power.................11-2
"FD".................................................................................16-62 Ventilating Air Cross Connection...............................11-1
"FMS APPROACH"........................................................16-24 Airport Suitability..............................................................18-7
"FWC".............................................................................16-61 Airstart Ignition...................................................................1-3
"GS".................................................................................16-61 Air-To-Air Precooler...........................................................9-2
"HDG".............................................................................16-61 Alternator
"IAS"...............................................................................16-61 Patch Cable....................................................................2-2
"ILS"................................................................................16-61 Troubleshooting.............................................................2-2
"LOC"..............................................................................16-61 Altimeter
"L-R WING TEMP LOW"................................................10-3 Pressure Set Knob Maxed Out...................................16-62
"MACH"..........................................................................16-61 Altitude Alerting System.................................................16-76
"Miscompare" Blue Annunciator (IRS)..........................16-54 Altitude Preselect
"PITCH"..........................................................................16-61 9999...........................................................................16-77
"ROLL"...........................................................................16-61 Angle of Attack System...................................................16-89
"SENSOR DC BUS ON BATT"..............................2-19, 20-8 Anti-Icing
"WING A/I ON"................................................................10-3 "L-R WING TEMP LOW"..........................................10-3
"WING WARM"...............................................................10-3 Anti-Icing Using Apu Bleed Air.................................10-3
“APU ALT BRG FAIL”......................................................6-2 In Flight.........................................................................1-7
“APU ALT HOT”................................................................6-2 Pitot Heat.....................................................................10-4
“APU ALT OFF”.................................................................6-2 Taxi and Takeoff...........................................................1-7
“AUX AC PWR FAIL”.......................................................6-2 Windshield Heat..........................................................10-3
“BRAKE MAINTENANCE REQUIRED”.....................14-16 Wing Anti-Ice..............................................................10-3
12th Stage Air......................................................................9-1 Anti-Icing Using Apu Bleed Air........................................10-3
7th Stage Air........................................................................9-1 Anti-Skid..................................................................1-8, 14-16
8.33 kHz Channel Spacing..............................................16-86 Failure Considerations.......................................1-6, 14-17
Background................................................................16-86 Partial Brake Failure..................................................14-17
Delayed Implementation............................................16-86 Wheel Snubbing on Retraction..................................14-17
FMS Tuning...............................................................16-88 AOA Reset Relay..............................................................20-3
Gables Modifications.................................................16-87 AOA System....................................................................16-89
8110.60............................................................................16-20 Approach
9.8 Differential Warning..................................................16-74 Authorizations...........................................................16-24
ABEX..................................................................................1-9 Landing/Climb Gradients............................................18-4
AC Alternators.....................................................................2-1 Limitations.................................................................16-24
AC Busses..........................................................................2-17 Missed Approach Prompt..........................................16-30
AC powered DU and Nose Cooling Fans..........................20-1 Approaches
Accessory Gear Box............................................................7-8 FMS...........................................................................16-24
ACM Bypass Shutoff Valve-Activation............................20-4 GPS............................................................................16-24
ACN...................................................................................18-7 Approved Tailwind..............................................................1-6
ACT Bypass Shutoff Valve...............................................11-2 APU.....................................................................................6-1
ACU Alternator Bearing Failure.............................................6-2
Bypass Shutoff Valve..................................................11-2 Alternator Hot................................................................6-2
Precooler........................................................................9-2 Alternator Off Annunciation.........................................6-2
Adverse Operations Anti-Icing Using Apu Bleed AIR................................10-3
Rainy Weather........................................................19-19 APU AIRBORNE STARTS..........................................6-5
Adverse Weather Auto Load Shedding......................................................6-6
Hot Weather Ops.......................................................19-16 Battery Switches............................................................6-1
Adverse Weather Ops.................19-8. See Cold Weather Ops Bleed Air........................................................................6-1
Gulfstream IV Notes I-2
Revision 2-98 Index

Dispatch With A Failed Converter................................6-3 ASC 221............................................................................20-5

Door...............................................................................6-7 ASC 231A................................................................2-13, 20-5
Door Closing..................................................................6-7 ASC 238............................................................................20-5
EGT........................................................................1-4, 6-1 ASC 239............................................................................20-5
Electrical Output............................................................6-5 ASC 240.................................................................16-59, 20-5
Electronic Load Warning System..................................6-6 ASC 243...................................................................10-1, 20-6
ELWS............................................................................6-6 ASC 255.................................................................16-68, 20-6
Exceedances...................................................................6-1 ASC 260..............................................................14-12, 20-6
Fire.................................................................................6-2 ASC 261........................................................18-10, 20-6, 20-9
Fire Extinguisher...........................................................6-7 ASC 264............................................................................20-6
High Altitude Inspection Requirement..........................6-6
ASC 266..................................................16-11, 18-10, 20-6
High Altitude Logging Requirements...........................6-6
ASC 280............................................................................20-6
HIGH ALTITUDE MOD..............................................6-6
ASC 285.....................................................................2-4, 20-7
High RPM Test..............................................................6-1
ASC 288............................................................................20-7
Limitations.....................................................................1-4
ASC 295............................................................................20-7
Low Battery Voltage Start.............................................6-3
ASC 296............................................................................20-7
Max APU AC Load for Engine Start...........................7-10
ASC 298.....................................................................9-5, 20-7
MEL Considerations......................................................6-3
ASC 302.................................................................14-10, 20-7
Minimum Voltage Start.................................................6-3
ASC 304..............................................................1-3, 7-6, 20-8
Overspeed......................................................................6-6
ASC 306............................................................................20-8
Power Failure Annunciator............................................6-2
ASC 307............................................14-22, 18-11, 20-4, 20-8
RPM...............................................................................6-1
ASC 313............................................................9-2, 12-6, 20-8
Shutdown.......................................................................6-7
ASC 314.................................................................18-11, 20-8
Start Parameters.............................................................1-4
ASC 320.................................................................18-10, 20-8
APU Alternator....................................................................2-2
ASC 327...................................................................2-19, 20-8
APU Shutdown Modification............................................20-2
ASC 345..........................................................4-1, 16-78, 20-9
APU Start
ASC 349...................................................................16-3, 20-9
External AC & DC Power.............................................6-5
ASC 350........................................................18-11, 20-6, 20-9
External AC Power........................................................6-5
ASC 351............................................................................20-9
External DC...................................................................6-3
ASC 359..............................................................9-1, 9-3, 20-9
APU Start Contactor Replacement....................................20-5
ASC 364............................................................9-7, 12-6, 20-9
APU starter drop-out light.................................................20-1
ASC 381...............................................................19-11, 20-10
Area Navigation...............................................................16-16
ASC 390..........................................................................20-10
ARINC 424......................................................................16-27
ASC 394..............................................................................7-4
Arktika..........................................................................19-16 ASCB...............................................................................16-55
Artika 2000......................................................................19-16 Data Acquisition Units (DAU)..................................16-56
ASC Failure........................................................................16-56
Weight Improvements...............................................18-10 Aspen ASC......................................................................18-10
ASC 001............................................................................20-1 Aspen OIS..........................................................................18-4
ASC 010............................................................................20-1 AT
ASC 013............................................................................20-1 Auto Change..............................................................16-62
ASC 049A..........................................................................20-1 Failure........................................................................16-62
ASC 050............................................................................20-1 Power Supply.............................................................16-62
ASC 054................................................2-11, 2-12, 2-15, 20-1 Auto Change........................................................................5-3
ASC 061.................................................................18-10, 20-2 Auto Changeover.............................................................14-18
ASC 069............................................................................20-2 Auto Ground Spoilers Factored into Lndg Dist.................20-8
ASC 096..............................................................................6-6 Auto Paging.....................................................................16-34
ASC 098............................................................................20-2 Auto Top Compact..........................................................16-58
ASC 102............................................................................20-2 Automatic Pressurization...................................................12-2
ASC 112.....................................................................2-5, 20-2 Autopilot..............................................................................1-9
ASC 118...................................................................14-1, 20-2
Autopilot Disconnect Switch Stuck.............................16-63
ASC 119............................................................................20-2
Autothrottle..............................................................1-8, 16-14
ASC 126............................................................................20-3
Descents.....................................................................16-15
ASC 129............................................................................20-3
Hold...........................................................................16-15
ASC 131.....................................................................3-1, 20-3
Hunting......................................................................16-15
ASC 135.................................................................14-15, 20-3
Requirements For Engagement.................................16-15
ASC 151.....................................................................7-7, 20-3
Auxiliary Hydraulic System..............................................13-3
ASC 157...................................................................12-6, 20-3
Auxiliary Power Unit...........................................................6-1
ASC 163............................................................................20-3
Avionics.............................................................................16-1
ASC 166..............................................14-13, 15-7, 15-9, 20-3
FMS Technical Newsletter..........................................16-1
ASC 167.................................................................14-23, 20-4
Avionics Standard Communications Bus................See ASCB
ASC 170...................................................................11-2, 20-4
Baggage Door Seals.............................................................9-6
ASC 176...................................................................20-4, 20-6
Balancing Fuel Tanks Airborne...........................................5-2
ASC 178............................................................................20-4
Banana Box..........................................................................7-8
ASC 190............................14-22, 18-9, 20-4, 20-6, 20-8, 20-9
Batteries
ASC 198...................................................................11-2, 20-4
Battery Charger Switching..........................................2-11
ASC 210............................................................................20-4
Battery Power Flight......................................................2-9
ASC 212............................................................................20-5
Charger TR Mode........................................................2-11
ASC 214............................................................................20-5
Chargers.......................................................................2-10
ASC 220............................................................................20-5
Gulfstream IV Notes I-3
Revision 2-98 Index

De-bounce Circuit........................................................2-10 Bus Faults..........................................................................2-24

Deep Discharge............................................................2-10 Essential AC................................................................2-25
Door Closing..................................................................2-9 Essential DC................................................................2-24
Relays Sticking............................................................2-10 Bus Power Control Units (BPCU).....................................2-24
Temperature Sensing...................................................2-11 Bypass Shutoff Valve........................................................11-2
Battery Charger Cabin Altimeter.................................................................12-7
Failure............................................................................1-9 Cabin Depressurization In Flight.......................................12-5
Unflagged Failure........................................................2-11 Cabin Pressure Stabilization..............................................12-6
Battery Charger and Control Improvement.......................20-1 Cabin Pressurization Stabilization.....................................20-8
Battery Charger Switching................................................2-11 Cabin Temperature Control...............................................11-2
Battery Chargers................................................................2-10 Carbon Brake Grabbing...................................................14-21
Battery Tie Bus..................................................................2-20 Cat II Certification.............................................................20-2
Battery Tie Contactors.......................................................2-20 Check Valves.....................................................................12-6
Battery/External Air Start Procedure.................................7-11 Chemical Deicers............................................................10-2
BCS..................................................................................14-18 Circuit Breaker Panels.......................................................2-25
Bird Ingestion....................................................................7-10 Circuit Breakers
Bird Protection...................................................................10-3 Black Faced.................................................................2-25
Bleed Air Feeder Circuits.............................................................2-25
Precooler........................................................................9-2 Locator Codes..............................................................2-25
Bleed Air Malfunction Procedures......................................9-4 Red Faced....................................................................2-25
Bleed Air Malfunctions.......................................................9-3 Clamping.........................................................................16-15
Bleed Air Precooler.............................................................9-2 Climb Gradient
Bleed Air Valves.................................................................9-3 Normal.........................................................................18-3
Bleed Ring...........................................................................7-7 Rule of Thumb.............................................................18-3
Bleeding Flight & Combined System Pressures................13-6 Climb Segments.................................................................18-3
Boost Pumps........................................................................5-3 Climb Speed....................................................................16-32
Auto Change..................................................................5-3 CNS/ATM.......................................................................16-21
Freezing Problems.........................................................5-4 Cockpit/Cabin Temp Sensor Power Source......................20-4
Power Considerations....................................................5-3 Cold Weather Ops.............................................................19-9
BPCU.................................................................................2-24
Close Entrance Door for Towing...........................19-16
Brake Confidence Check.................................................14-18
Deicing.......................................................................19-11
Brake Control System (BCS)..........................................14-18
Engine Pre-Heat...........................................................19-9
Brake Messages -- Brake-By-Wire Airplanes.....................1-7
Brake System............................................................1-7, 14-16 Ground Deicing......................................................19-11
"BRAKE MAINTENANCE REQUIRED"...............14-16 Overnight Securing....................................................19-11
Anti-Skid...................................................................14-16 Securing Basics......................................................19-11
Auto Changeover.......................................................14-18 Type IV Fluid............................................................19-13
Bang-Bang Breaking.................................................14-17 Combined Hydraulic System.............................................13-1
Brake Confidence Check...........................................14-18 Fluid Loss....................................................................13-2
Brake Control System (BCS)....................................14-18 Comparison Monitor........................................................16-62
Brake Failure On Landing:........................................14-20 Comparison Monitor Annunciations...............................16-60
Brake Fires.................................................................14-17 Component Failure Limitations...........................................1-6
Brake Freeze Precautions.......................................14-19 Components
Brake Temperature Monitoring System....................14-23 High Removal Items..................................................16-93
BTMS........................................................................14-23 Compressor stalls.......................................................7-8, 10-1
Carbon Brake Grabbing.............................................14-21 Contaminated Runway
Check Pedal Brake Pressure In Flight.......................14-18 T/O Data....................................................................18-12
Dunlop (HMAB) System...........................................14-22 Converter
Dunlop Brake-By-Wire System.................................14-22 -509 Converter...............................................................2-4
Frozen Brakes............................................................14-19 AC Power Failure..........................................................2-4
Frozen Brakes -- Grnd Procedures............................14-20 Dash 509 Converter.......................................................2-4
Goodyear Brake By Wire System.............................14-16 DC Failure...................................................................2-22
Messages....................................................................14-16 DC Power Failure..........................................................2-4
Parking Brake............................................................14-21 Drop Off........................................................................2-4
Reset Brake Messages...............................................14-18 Failed Fan Latching.......................................................2-4
Single Engine Taxi Considerations...........................14-21 Fan Fail..........................................................................2-3
Brake Temperature Monitoring System............................20-4 Fan Message..................................................................2-3
Brake-By-Wire Enhancement............................................20-7 Fans................................................................................2-3
Brakes High elevation/Cold Wx Ops........................................2-4
Frozen..........................................................................19-9 Loads...........................................................................2-22
Braking Effectiveness......................................................18-12 Patch Cable....................................................................2-2
Braking System Power Failure Modes.....................................................2-4
Software Update........................................................14-21 Switches.........................................................................2-2
Breakfast Minutes..............................................................19-1 Test Cable......................................................................2-2
BRNAV.....................................................16-21, 16-94, 19-29 Troubleshooting.............................................................2-2
BTMS.....................................................................14-23, 20-4 Turning OFF a Converter During Taxi..........................2-4
Buddy Starts......................................................................7-12 Converter Fan Failed Output Latch...................................20-7
Bus Control And Power Distribution................................2-21 Converters
Bus Controller High Elevation Drop Off...............................................7-2
Symbol Generator Failure.........................................16-59 Converters............................................................................2-2
Gulfstream IV Notes I-4
Revision 2-98 Index

Cowl Anti-Ice....................................................................10-1 Closing Problems.........................................................17-1

Crossbleed Cowl Anti-Ice...........................................10-1 Single Battery Closing.................................................17-1
Igniter Requirement.....................................................10-1 Door Closing........................................................................2-9
Inoperable Anti-Ice Valve...........................................10-2 Door Retraction Failure.....................................................13-4
Max Temperature for Use............................................10-1 Door Seal
Cowl Anti-Ice Pressure Warning Switch...........................20-6 Inflation.......................................................................12-6
Cowl Anti-Icing Modification (ASC 364)................................................9-7
Ground Operations......................................................10-2 Door Seal Failures.............................................................12-5
Crossbleed Cowl Anti-Ice.................................................10-1 Door Seal Fix (ASC 364)..................................................12-6
Crossing Point....................................................................16-3 Door Seal System..............................................................20-9
Custom Database.............................................................16-11 Door Seals
DADC Baggage.........................................................................9-6
Failure........................................................................16-75 Check Valves...............................................................12-6
Miscompare...............................................................16-75 DU16-57
Dash-XXX.......................................................................16-11 Auto Top Compact....................................................16-58
Data Acquisition Units....................................................16-56 Availability With Dual Converter Failure.................16-58
Data Loader.....................................................................16-12 Comparison Monitor Annunciations.........................16-60
DL-800/900...............................................................16-12 Main DC Busses and SES Powered.........................16-60
DL-900.......................................................................16-48 Power Failure Modes.................................................16-57
High Density Disks....................................................16-14 Power Sources................................................16-57, 16-59
High Speed Loading..................................................16-13 Red X'ing...................................................................16-59
Problems....................................................................16-13 Screen Burn In........................................................16-57
Database.............................................................................16-8 Status With A Dead Essential DC Bus......................16-60
Clearing Custom Database........................................16-11 Dual Control Windshield Heat Switches...........................20-5
High Speed Loading..................................................16-13 Dual Converter Failure Landings........................................2-8
NZ2EAST....................................................................16-9 Dual Datum System.............................................................7-1
NZ2WEST...................................................................16-9 Dual Pack Operations..........................................................9-2
Regional.......................................................................16-9 Dunlop Brake by Wire Wheels/Brakes/Tires....................20-6
Split Coverage.............................................................16-9 Dunlop Brake-By-Wire System.......................................14-22
Updates........................................................................16-9 Dunlop HMAB Brake System
WORLD2.....................................................................16-9 Anti-Skid...................................................................14-22
DAU.................................................................................16-56 Landing With Parking Brake Only............................14-23
Channel Fail...............................................................16-56 Dunlop HMAB System
Miscompare...............................................................16-56 Brake Pressure Indications........................................14-22
DBDI Dunlop HMAB, Wheels & Tires.......................................20-8
"DDRMI E" (or "DBDI E") CB................................16-55 Dunlop Hydro-Mech Analog Brake Sys.........................14-22
Directional Signal Sources........................................16-55 E-Bus Alternate Power Modification................................20-5
DC Busses..........................................................................2-17 ECS Pack Sequencing During Engine Start......................20-3
DC Converter Failure........................................................2-22 EGPWS............................................................................16-79
DDRMI.....................................................................See DBDI Erroneous Wx Radar Annunciation...........................16-82
De-bounce Circuit..............................................................2-10 EICAS Cabin Pressurization Warning..............................12-3
Deep Discharge..................................................................2-10 EICAS On Standby Electrical Power System Mod...........20-5
Degrade Mode.................................................................16-25 EICAS vs. Standby Fuel Indicators.....................................5-2
De-Icing.............................................................................10-4 E-Inverter.............................................................................2-6
Arktika....................................................................19-16 E-Inverter Switchlight.......................................................2-22
Artika 2000................................................................19-16 Electrical Bus Energized Alert..........................................20-2
Tail De-Icing................................................................10-4 Electrical Loads.................................................................2-22
Type IV......................................................................19-13 Electrical Power Management Panel (EPMP)...................2-21
Deicing Operations.......................................................19-11 Electrical System Busses...................................................2-17
Deleting the Active Flight Plan.......................................16-35 Electrical Systems................................................................2-1
Demonstrated Crosswind.....................................................1-6 Electronic Checklist Installation........................................20-4
Depressurization................................................................12-5 Electronic Load Warning System (ELWS).........................6-6
ELWS..................................................................................6-6
Desert Operations.........................................................19-22
Configuration Light.......................................................6-6
Designated Crossing Point.................................................16-3
Test System....................................................................6-7
Digital Air Data Computer......................................See DADC
Emergency Batteries..........................................................2-12
Digital Bearing Distance Indicator...........................See DBDI
"Thru" vs. "Or" Systems..............................................2-13
Digital Distance Radio Magnetic Indicator..............See DBDI
Activation For No Obvious Reason.............................2-14
Dimension............................................................................1-1
Charging......................................................................2-12
Wingspan.......................................................................1-1
Configurations.............................................................2-13
Dimensions..........................................................................1-1
Consumers...................................................................2-13
Discriminator Circuit.........................................................12-2
Dispatch Discharge Rates........................................................2-12
Failed Converter............................................................6-3 Lead Acid....................................................................2-12
Dispatch Critical Component List...................................16-93 Nickel-Cadmium.........................................................2-12
Display Unit..................................................................See DU Secure-A-Plane............................................................2-13
Display Units URDC..........................................................................2-13
Screen Burn In...........................................................16-57 Emergency Extension With Gear Down...........................14-6
Display Units (DU)..........................................................16-57 Emergency Gear Extension...............................................14-6
Door Emergency/Abnormal Checklist........................................19-6
Gulfstream IV Notes I-5
Revision 2-98 Index

Engine Fire Protection.....................................................................8-1

Vibration..............................................................See EVM Fire Warning System
Engine Cold Start Procedure.............................................7-13 Engine Hot.....................................................................4-4
Engine Hot....................................................................4-4, 7-8 Fire Handle....................................................................4-3
Engine Limiter Summary....................................................7-5 Flap Asymmetry Indication System..................................20-2
Engine Nacelles Flaps...........................................................................1-5, 15-1
Cowling Safety............................................................7-13 Asymmetry..................................................................15-2
ENGINE OIL.......................................................................7-9 Emergency Flap Handle Out of Detent.......................15-3
Engine Start.......................................................................7-10 Emergency Flaps.........................................................15-2
Engine Sync.........................................................................7-9 Extension With Combined Hydraulic Failure.............15-1
Engine Torching..................................................................7-7 Flap Control CB...........................................................15-2
Enhanced Gnd Prox Warning System..................See EGPWS Flap Control Valve......................................................15-1
Enhancement Levels..........................................................18-9 Manual Flap Control CB.............................................15-2
Enroute Navigation..........................................................16-19 Overspeed Extension...................................................15-2
EPMP.................................................................................2-21 Stabilizer Failure..........................................................15-2
"EPMP POWER FAIL"...............................................2-21 Flaps Extended Speed..........................................................1-5
Battery Ammeters........................................................2-22 Flight Controls...................................................................1-11
Battery Voltmeters.......................................................2-22 Gust Lock....................................................................1-11
Blank Panel..................................................................2-21 Flight Director..............................................................16-63
DC Volts......................................................................2-22 Approach Mode.........................................................16-64
Digit replacement........................................................2-23 Comparison Monitor..................................................16-62
E-Inverter Switchlight.................................................2-22 False Localizer Capture.............................................16-64
Electrical Loads...........................................................2-22 Takeoff Mode............................................................16-64
POWER MANAGEMENT.........................................2-22 Testing.......................................................................16-63
Power Sources.............................................................2-21 Turbulence.................................................................16-63
Switching And Metering.............................................2-22 Flight Following................................................................19-7
Total Power Failure.....................................................2-21 Flight Guidance Computer..............................16-63. See FGC
Voltmeter Sources.......................................................2-22 Flight Idle System................................................................7-1
EPMP Blank Panel............................................................2-21 Light...............................................................................7-2
EPR Exceedance..................................................................7-6 Flight Management Computer...........................................16-1
Erratic Pressurization.........................................................12-3 Flight Management System
Essential AC Bus...............................................................2-17 Limitations.....................................................................1-8
Phase B & C Consumers.............................................2-17 Flight Plan Entry
Essential DC Bus...............................................................2-17 Auto Paging...............................................................16-34
"SENSOR DC BUS ON BATT".................................2-19 Naming Flight Plans..................................................16-34
Load.............................................................................2-17 Flight Planning
Loss Of -- Effect On Pressurization............................2-20 Airport Suitability..............................................18-7, 18-8
Loss of Essential DC Bus............................................2-17 Early Descent Penalty................................................18-11
Pilot Induced Failure...................................................2-19 FliteStar.......................................................................18-5
Powered by the Battery Bus........................................2-17 FMS Required Fuel Calculation..................................18-6
Essential DC Bus Failure Fuel Consumption........................................................18-6
DU Status...................................................................16-60 Load Bearing...............................................................18-8
EVM..................................................................................7-10 Route Planning Assumptions.......................................18-6
Primary Vibration Sensor............................................7-10 Short Range Optimization.........................................18-11
Secondary Vibration Sensor........................................7-10 Flight Power Shutoff
Test..............................................................................7-10 Problems......................................................................13-4
Exceedance Flight Power Shutoff Handle.............................................1-11
APU...........................................................................16-75 Flight Safety International.................................................19-2
Most Common...........................................................16-65 FliteStar.............................................................................18-5
Nuisance Message.....................................................16-75 Floater Waypoints............................................................16-10
Exceedances FM Immunity Program....................................................16-85
EPR................................................................................7-6 FMS...................................................................................16-1
External AC.......................................................................2-15 Approach Authorizations...........................................16-24
External DC.......................................................................2-15 Approach Limitations................................................16-24
FAA Notice 8110.60........................................................16-20 Approaches................................................................16-43
Failed Fan Latching.............................................................2-4 Arcs............................................................................16-45
Fault Warning Area Navigation.........................................................16-16
9.8 Differential Warning............................................16-74 Arrival........................................................................16-43
Fault Warning Computer (FWC)...................16-65. See FWC Batter Replacement......................................................16-7
FD See Flight Director Check Position Sensor...............................................16-16
Feeder Circuits...................................................................2-25 Climb/Cruise/Descent................................................16-40
FGC.................................................................................16-63 Configuration Changes..............................................16-46
Fire Crossing Points..........................................................16-47
"ENG FIRE LOOP ALRT"...........................................8-1 Custom Database............................................16-11, 16-47
"ENGINE HOT"............................................................8-1 Database.......................................................................16-8
Handle............................................................................8-1 Degrade Mode...........................................................16-25
Invalid Indication...........................................................8-1 Delete Scratch Pad Entry...........................................16-35
Valid Indication.............................................................8-1 Deleting the Active Flight Plan.................................16-35
Fire Detection......................................................................8-1 Direct Key..................................................................16-48
Fire Handle...................................................................4-3, 8-1 Enroute and Terminal Operation...............................16-19
Gulfstream IV Notes I-6
Revision 2-98 Index

Flight Plan List..........................................................16-42 Excessive.....................................................................18-5

Flight Summary.........................................................16-48 FMS Required Fuel Calculation..................................18-6
Flyover.......................................................................16-45 FUEL FILTER LIGHT........................................................5-4
GPS Based Area Navigation......................................16-17 Fuel Flow Extremes.............................................................7-8
Hardware.....................................................................16-2 Fuel Imbalance, Maximum..................................................1-3
Heading Mode (True/Mag)........................................16-47 Fuel Indicators
Holding Patterns........................................................16-45 EICAS vs. Standby Fuel Differences............................5-2
Initialization...................................................16-33, 16-36 Fuel Pressure Low Lights....................................................5-4
Land/GA Init..............................................................16-41 Fuel Probes..........................................................................5-1
Landing Data.............................................................16-41 Fuel Quantity.......................................................................5-1
Letters By VOR Freqs on Prog Page.........................16-44 Fuel System..................................................................1-3, 5-1
Linking Stored Flight Plans.......................................16-36 Auto Fueling Shutoff Valves.........................................5-1
Lockup.......................................................................16-11 Balancing Fuel Tanks Airborne.....................................5-2
Maintenance Functions..............................................16-46 Boost Pumps..................................................................5-3
Missed Approach.......................................................16-44 Fuel Filter Light.............................................................5-4
Missed Approach Prompt..........................................16-30 Fuel Flow Extremes.......................................................7-8
Multiple VOR Failures................................................16-7 Fuel Pressure Low Lights..............................................5-4
Nav Database...............................................................16-8 Fuel Probes....................................................................5-1
Nav Index..................................................................16-42 Fuel Quantity.................................................................5-1
Nav Source Weighting...............................................16-17 Low Level Lights...........................................................5-2
Navigation Source Weighting...................................16-17 Maximum Fueling Technique.......................................5-1
Non-Precision Approachs..........................................16-19 Pressure Defueling.........................................................5-2
NOTAM.....................................................................16-45 Rapid Shifts in Quantity................................................5-1
NZ-4.X Software.........................................................16-3 Remote Shutoff Switches..............................................5-2
NZ-9401 Software.......................................................16-2 Fuel Tankering.................................................................18-11
Operating Notes, Additional......................................16-36 FWC
Operating Tips...........................................................16-33 Corrupted Data Files..................................................16-68
Orbits.........................................................................16-45 Download Frequency.................................................16-67
Patterns......................................................................16-45 False Exceedance Warnings......................................16-67
Perf Data....................................................................16-39 Gear Door Pin(s) Left In -- On Ground.............................14-4
Performance Computer (PZ).....................................16-11 Gear Doors.........................................................................14-1
Performance Index.....................................................16-37 Gear Down Ferry...............................................................14-7
Performance Initialization.........................................16-37 Gear Handle Light.............................................................14-2
Position Initialization.................................................16-47 Gear Horn..........................................................................14-2
Position Sensors.........................................................16-44 Gear Malfunction...............................................................14-4
Procedure Turn..........................................................16-45 Gear Warning System
Radial.........................................................................16-45 Gear Horn....................................................................14-2
RAIM.........................................................................16-23 Test..............................................................................14-2
Rapid Initialization....................................................16-34 GIV
Runway Centerline Extensions..................................16-48 AS 18-9
Software.......................................................................16-2 IP 18-9
Split World Database...................................................16-9 SP 18-9
Stored Flight Plan Data..............................................16-41 GIV ED..............................................................................18-9
Take Off Data............................................................16-40 GIV EN..............................................................................18-9
Take Off Init..............................................................16-39 GIV EP..............................................................................18-9
Tune Function............................................................16-44 GIV ES..............................................................................18-9
Versions.......................................................................16-2 GIV Optimization............................................................18-11
VNAV............................................................16-31, 16-49 Climb vs. Range........................................................18-11
Waypoint List............................................................16-42 Early Descents...........................................................18-11
What-If.......................................................................16-41 Fuel Density...............................................................18-11
FMS navigation based solely on GPS sensor......................1-8 Fuel Tankering...........................................................18-11
FMS Product Support........................................................16-1 OIS-2.........................................................................18-12
FMS/SPZ-8000 Maintenance Test Switch........................20-5 Short Range...............................................................18-11
Forward Lavatory FOD Problem.......................................7-13 Weight Sensitivity.....................................................18-11
Frozen Brakes.........................................................14-19, 19-9 GIV SP.............................................................................18-10
Fuel Performance Improvements.......................................18-10
Balancing In Flight........................................................1-3 SP Cut-In...................................................................18-10
Erroneous Low Level Warning.....................................1-4 Go Around Mode.............................................................16-77
Intertank Valve..............................................................1-3 Goodyear Brake By Wire System...................................14-16
Loads.........................................................................18-11 GPS
Low Level Warning.......................................................1-4 Approaches................................................................16-43
Maximum Filling Aircraft Position...............................1-4 Approved Uses..........................................................16-18
Maximum Imbalance.....................................................1-3 Augmentation............................................................16-20
Maximum Load.............................................................1-3 GPS Only or Stand Alone Approaches......................16-19
Tank Temperature for Transfer.....................................1-3 Missed Approach.......................................................16-44
Tankering...................................................................18-11 Navigation Categories...............................................16-18
Temperatures.................................................................1-3 Non-GPS Approaches................................................16-19
Fuel Boost Pumps Non-Precision Approachs..........................................16-19
Quick Turn Considerations............................................5-5 Oceanic/Remote Operation........................................16-20
Fuel Consumption Overlay Approaches..................................................16-19
Gulfstream IV Notes I-7
Revision 2-98 Index

RAIM.............................................................16-23, 16-50 Igniter Box With Bigger Heat Sinks..................................20-8

GPWS..............................................................................16-79 Igniter Modification.............................................................7-7
Gross Weight Igniters.................................................................................7-6
Enhancements..............................................................18-9 Requirement With Cowl Anti-Ice On..........................10-1
Ground Idle..........................................................................7-2 ILS
Ground Proximity Warning System........................See GPWS Premature Loc Capture..............................................16-64
Ground Service Valve Cover.............................................20-8 Increased Zero Fuel Weight..............................................20-2
Ground Spoilers.................................................................15-5 Inertial Reference Systems...............................16-52. See IRS
Flap Override Switch...................................................15-6 Inertial Reference Units...............................................See IRS
Hydraulic Failure.........................................................15-6 Information Resources.......................................................19-1
Manual Deployment....................................................15-5 Inlet Guide Vanes................................................................7-7
Test..............................................................................15-6 Inoperable Anti-Ice Valve.................................................10-2
Wheel Spin-up.............................................................15-5 Inoperative Prior to T/O Max Fuel 9,000............................1-6
Ground Spoilers Not Operative for Takeoff........................1-6 Invalid Fire Indication.........................................................8-1
Gulfstream IRS...................................................................................16-52
Customer Frequency....................................................19-7 "Battery Fail".............................................................16-52
Gust Lock..........................................................................1-11 Align Light In Flight..................................................16-53
Gust Lock Application.......................................................13-6 Alignment......................................................................See
Head Up Display............................................16-90. See HUD Battery Test................................................................16-52
Heavy Rain......................................................................19-19 Blue "Miscompare" Light..........................................16-54
Heavy Rain Operations................................................19-19 Cooling Fan Failure...................................................16-53
Helpline Contact Numbers................................................19-7 IRS #1 Failure............................................................16-53
HF Radio MEL Considerations..................................................16-54
Tests...........................................................................16-88 Monitor......................................................................16-53
Hi Intensity Anti-Collision Light......................................20-1 Power Sources...........................................................16-52
High Altitude Operations...................................................11-2 Third Unit..................................................................16-18
High Bleed Pressure............................................................9-3 IRS Batteries......................................................................2-14
High Elevation Ops Charging......................................................................2-14
Engine Start/Taxi.......................................................19-18 Fail...............................................................................2-14
High Removal Components.............................................16-93 IRU....................................................................16-52. See IRS
HMAB System................................................................14-22 Isolation Valve.............................................................7-3, 9-4
Holding Pattern Speed Control........................................16-16 Broken Switch...............................................................9-6
Holding Patterns..............................................................16-16 Check If Closed.............................................................9-6
Honeywell Manual Opening............................................................7-3
Radar..........................................................................16-78 Stuck Open....................................................................9-6
James Brake Index...........................................................18-12
Y2K Effects............................................................16-91
Landing "G" Meter............................................................20-2
Honeywell Web Site..........................................................16-1
Landing Gear..............................................................1-5, 14-1
Hot Weather Ops.............................................................19-16
Disconnected Switch...................................................14-5
Avionics Cooling.......................................................19-17
Door Pins Left In -- On Ground..................................14-4
DADC Failure............................................................19-17
Emergency Extension With Gear Down.....................14-6
HP RPM...............................................................................1-2
Emergency Gear Extension.........................................14-6
HUD.................................................................................16-90
Failure to Retract.........................................................14-4
Hydraulic Fluids................................................................13-1
Gear Door Pins Left In -- Airborne.............................14-4
Hydraulic Indication Modification....................................20-5
Gear Doors...................................................................14-1
Hydraulic Oil
Gear Down Ferry.........................................................14-7
Mixing Brands.............................................................13-1
Gear Warning System..................................................14-2
Hydraulic Power Systems..................................................13-1
How To Open A Closed Uplock..................................14-5
Hydraulic System
Main Gear Uplock Closed...........................................14-4
Bleeding Flight & Combined System Pressures..........13-6
Malfunction.................................................................14-4
Combined.....................................................................13-1
Partial Gear Extension.................................................14-5
Low Combined System Pressure.................................13-5
Partial Retraction.........................................................14-4
Low Hydraulic Pressure Indications............................13-4
Retraction Problems...........................................14-7, 14-9
Quantity Indications....................................................13-6
Landing Gear And Brakes.................................................14-1
Utility...........................................................................13-2
Landing Gear Speeds...........................................................1-5
Hydraulic Systems
Landing Gear Warning System
Loss Of Flight Or Combined.......................................13-2
Horn Mute Button........................................................14-3
Hydraulics
Landing G-Meter...............................................................14-1
Speedbrake Deployment..............................................15-7
Landing Lights.....................................................................1-8
Hydroplaning...................................................................19-19
Latching.............................................................................10-3
Ice And Rain Protection....................................................10-1
Lavatory
Icing
Forward Lavatory FOD Problem.................................7-13
Anti-Icing Using Apu Bleed Air.................................10-3
Leading Edge Sealants.....................................................15-12
Engine Vibration with Icing........................................10-1
Lighting...............................................................................3-1
Ground Operations......................................................10-2
Lightning Strikes.............................................................19-20
Start Up In Icing Conditions........................................10-2
Limitations...........................................................................7-6
ICS Switch Replacement...................................................20-3
Airspeed.........................................................................1-5
Igniter
Anti-Icing.......................................................................1-7
Modification..................................................................7-7
Anti-Skid.......................................................................1-8
Plug Failure....................................................................7-6
Brake System.................................................................1-7
Gulfstream IV Notes I-8
Revision 2-98 Index

Component Failure........................................................1-6 RNP-5........................................................................16-22

Engine Start.................................................................1-10 Runway End Offsets..................................................16-35
Engine Synchronizer......................................................1-8 Vertical (VNAV)...................................16-31. See VNAV
Flaps...............................................................................1-5 Navigation above 85 N or S................................................1-8
Flaps Extended Speed....................................................1-5 Navigation Source Weighting.........................................16-17
FMS...............................................................................1-8 NBAA
Landing Gear.................................................................1-5 Air Mail.......................................................................19-4
Landing Gear Speeds.....................................................1-5 Airport Database..........................................................19-5
Landing Lights...............................................................1-8 Web Site......................................................................19-4
Max Turbulence Penetration.........................................1-5 Nitrogen In Gear System...................................................14-5
Max Windshield Wiper Speed.......................................1-5 Noise Certification.............................................................19-7
Speed Brakes.................................................................1-7 Non-Precision Approaches
Standby Electrical System.............................................1-9 VNAV........................................................................16-26
Takeoff and Landing.....................................................1-6 Nose Wheel Steering.......................................................14-10
Thrust Reversers............................................................1-8 Delayed Failure Indication........................................14-11
Linking Stored Flight Plans.............................................16-36 Effect of Combined and Utility System Loss............14-11
Load Shedding...................................................................2-22 Loss............................................................................14-10
Boost Pumps................................................................2-23 Problems....................................................................14-11
Loss Of Flight Or Combined Hydraulic Systems..............13-2 Towing.......................................................................14-11
Low Combined System Pressure.......................................13-5 Troubleshooting.........................................................14-11
Low Hydraulic Pressure Indications..................................13-4 Nose Wheel Steering Enhancement..................................20-6
Low Level Lights.................................................................5-2 Nose Wheel Steering Fail Annunciation...........................20-4
LP Cooling Air Outlet Gaskets..........................................20-7 Nosewheel Nutcracker.....................................................14-15
LP RPM...............................................................................1-2 NTSB.................................................................................19-5
Mach Trim And Yaw Damper Inoperative..........................1-6 Nutcracker
Mach Trim Compensation Inoperative................................1-6 Test Switch..................................................................1-10
Main Aircraft Batteries........................................................2-9 NUTCRACKER SYSTEM...................................1-9, 14-12
Main DC Bus Airborne While In Ground Mode..............................14-14
Power Source Cycling.................................................2-23 Corrosion Problems...................................................14-15
Main Door Closing..............................................................2-9 Eliminate Unnecessary Nutcracker Circuit...............14-15
Main Door Seals..................................................................9-6 L & R Nutcracker Circuit Breakers...........................14-12
Main Entry Door Landing In Airborne Mode........................................14-12
Retraction Failure........................................................13-4 Main Gear..................................................................14-12
Main Entry Door Retraction..............................................13-4 Nosewheel Nutcracker...............................................14-15
Main Wheel Well Heat....................................................19-11 Nutcracker Circuit Breaker........................................14-12
Maintenance Test Switch...................................................20-5 Nutcracker Test Switch.............................................14-15
Manual Pressurization.......................................................12-4 NZ-2000
Manual Reversion Conversion...................................................................16-3
Yaw Damper Considerations.....................................15-12 D Modification............................................................16-4
Manual Temperature Control............................................11-1 New Features...............................................................16-3
Marker Coordinates.........................................................16-35 Position Initialization Problem....................................16-4
Master Warning System......................................................4-1 NZ-2000 Conversion.........................................................20-9
Max Differential Pressure Vs Altitude..............................12-3
NZ2East..........................................................................16-9
Max Turbulence Penetration...............................................1-5
Maximum Gross Weight Increase to 75,000#...................20-9 NZ2West.........................................................................16-9
Missed Approach Prompt................................................16-30 NZ-4.X
Misting Out Of ACU Exhaust Ducts.................................11-1 Navigation Software....................................................16-3
Mixing Hydraulic Oil Brands............................................13-1 NZ5.0
Modification U................................................................16-66 Coming Features..........................................................16-6
Nav Database Features........................................................................16-5
Split Coverage.............................................................16-9 NDB Update Disks......................................................16-6
Nav System Definitions...................................................16-51 Upgrade.......................................................................16-4
Navigation Obstacle Clearance Using FMS.........................................18-4
BRNAV.....................................................................16-21 Oceanic Waypoint Entry Shortcuts.................................16-35
Categories Oil
Supplemental.......................................................16-18 Consumption..................................................................7-9
CNS/ATM.................................................................16-21 Limitations.....................................................................1-4
Deleting the Active Flight Plan.................................16-35 Quantity Check..............................................................7-9
Designated Crossing Point...........................................16-3 Temperatures.................................................................1-4
Enroute and Terminal Operation...............................16-19 Oil Grades............................................................................1-9
GPS............................................................................16-17 OIS-2...............................................................................18-12
GPS Approaches........................................................16-24 OIS-4.................................................................................7-10
Linking Stored Flight Plans.......................................16-36 OIS-7.................................................................................18-4
Oceanic Waypoint Entry Shortcuts...........................16-35 Online Resources...............................................................19-1
Outer Marker Coordinates.........................................16-35 Operating Information.........................................................1-1
Pacific........................................................................16-22 Outer Marker Coordinates...............................................16-35
Point Abeam Coordnates...........................................16-36 Outflow Valve...................................................................12-1
Position Sensor Disagreement...................................16-16 Outflow Valve Louver.......................................................20-1
Reselecting Bypassed Waypoints..............................16-34 Overfueling System.............................................................7-8
RNP-10......................................................................16-22 Overweight Landings........................................................14-1
Gulfstream IV Notes I-9
Revision 2-98 Index

Pack Engine Limiter Summary..............................................7-5

Bypass Shutoff Valve..................................................11-2 Engine Oil......................................................................7-9
Parking Brake..................................................................14-21 Engine Pneumatics........................................................7-2
Check Valve And Seals.............................................14-21 Engine Start.................................................................7-10
Parking System Engine Sync...................................................................7-9
Parking Brake Check Valve And Seals.....................14-21 Engine Synch.............................................................16-77
Partial Brake Failure........................................................14-17 Engine Torching............................................................7-7
Partial Gear Extension.......................................................14-5 Engine Vibration with Icing........................................10-1
PCN...................................................................................18-7 EVM............................................................................7-10
PDB...................................................................................2-24 Fire Warning System.....................................................4-2
Performance Flight Idle System..........................................................7-1
Initial Flight Planning Chart........................................18-1 Fuel Flow Extremes.......................................................7-8
SE Performance Loss...................................................18-1 Ground Idle....................................................................7-2
V1 Selection Criteria...................................................18-1 High Elevation Considerations......................................7-2
Wheel Loading............................................................18-7 High Pressure Section....................................................7-3
Performance Computer........................................................1-8 HP RPM.........................................................................1-2
Dash 920....................................................................18-10 Igniter Modification.......................................................7-7
Dash-XXX.................................................................16-11 Igniter Plug Failure........................................................7-6
Failure........................................................................16-12 Igniters...........................................................................7-6
Upgrade.....................................................................18-10 Ignition Ground Start ON Single Plug.........................20-3
Upgrades....................................................................16-11 Inlet Guide Vanes..........................................................7-7
Performance Computer (PZ)...........................................16-11 Limitations.............................................................1-2, 7-6
Performance Index...........................................................16-37 Low Pressure Section....................................................7-3
Performance Limited Takeoff...........................................18-4 LP RPM.........................................................................1-2
Pitot Heat...........................................................................10-4 Max APU AC Load for Engine Start...........................7-10
Pitot-Static System Oil Consumption............................................................7-9
Clogged Static Ports..................................................16-76 Overfueling System.......................................................7-8
Plug Failure..........................................................................7-6 Shutdown Without APU Running...............................7-13
Pneumatics...................................................................7-2, 9-1 Specifications.................................................................1-2
12th Stage Air................................................................9-1 Start
7th Stage Air..................................................................9-1 APU/External Air Pressure....................................1-10
Bleed Air Malfunctions.................................................9-3 Max start TGT.......................................................1-10
Bleed Air Precooler.......................................................9-2 Min Idle.................................................................1-10
Bleed Air Valves...........................................................9-3 Start Cycles............................................................1-10
Dual Pack Operations....................................................9-2 Start Problems..............................................................7-11
High Bleed Pressure......................................................9-3 Start Up In Icing Conditions........................................10-2
Isolation Valve.......................................................7-3, 9-4 Start Valve...................................................................1-10
Low Bleed Pressure During Descent.............................9-4 Synchronizer..................................................................1-8
Main Door Seals............................................................9-6 TGT...............................................................................1-2
No "SVO" Annunciation...............................................7-3 Thrust Limiter................................................................7-5
Single Pack Operations..................................................9-3 Top Temperature Control (TTC)...................................7-4
Start Valve Open...........................................................7-3 TTC................................................................................7-4
Point Abeam Coordnates.................................................16-36 Turbine Gas Temperature (TGT)..................................7-4
Position Sensor Turbine Rub.................................................................7-3
Third IRS...................................................................16-18 Precooler..............................................................................9-2
Power Annunciation (PFD).............................................16-33 Pressure Controller............................................................12-3
Power Distribution Box (PDB)..........................................2-24 Maximum Differential.................................................12-3
Power Fail............................................................................2-1 Pressure Defueling...............................................................5-2
Power Source Cycling.......................................................2-23 Pressurization
Power Sources.....................................................................2-1 Control to Manual If Power Is Lost.............................20-7
Powerplant Pressurization...........................................................1-10, 12-1
Vibration with Icing.....................................................10-1 Automatic Pressurization.............................................12-2
Powerplant...........................................................................7-1 Cabin Altimeter...........................................................12-7
High Elevation Considerations................................7-2 Cabin Depressurization In Flight.................................12-5
"ENGINE HOT"............................................................8-1 Cabin Pressure Stabilization........................................12-6
Accessory Gear Box......................................................7-8 Control Panel...............................................................12-2
Airstart.........................................................................1-10 Discriminator Circuit...................................................12-2
Airstart Ignition.............................................................1-3 Door Seal Failures.......................................................12-5
Battery/External Air Start Procedure...........................7-11 Door Seal Fix...............................................................12-6
Bleed Ring.....................................................................7-7 Erratic Pressurization...................................................12-3
Bleed System.................................................................9-1 Manual.........................................................................12-4
Buddy Starts................................................................7-12 Manual Mode...............................................................12-4
Bypass Drain Modification..........................................20-6 Max Differential Pressure Vs Altitude........................12-3
Centrifugal Oil Breather Outlet Tube Mod.................20-5 Maximum Differential.................................................12-3
Cold Start Procedure....................................................7-13 Outflow Full Closed In Flight.....................................12-3
Compressor stalls.................................................7-8, 10-1 Outflow Valve.............................................................12-1
DC Power Start............................................................7-11 Pressure Controller......................................................12-3
Dual Datum System.......................................................7-1 Pressurization Problems During Descent....................12-6
Dual Engine Flameout Procedure................................7-10 Ram Switch..................................................................12-5
Engine Hot.....................................................................7-8 Rate Limiting......................................................12-3, 12-4
Gulfstream IV Notes I-10
Revision 2-98 Index

Remote Aft Baggage Door Seal Release.....................12-6 Single Rudder Limit Light.................................................15-4
Safety Relief Valve......................................................12-1 Single Rudder Limit”.........................................................1-11
Three-In-One Altimeter...............................................12-7 Smoke Evacuation Valve...................................................20-3
Pressurization Control Panel.............................................12-2 Sole Means Navigation........................................16-19, 16-51
Pressurization Problems During Descent..........................12-6 SP Cut-In.........................................................................18-10
Primary Means Navigation...................................16-18, 16-51 Speed Brakes.......................................................................1-7
Primary Means Oceanic/Remote.....................................16-51 Speed Bug
Product Support.................................................................16-1 Synching Speed Bug to Current Speed......................16-78
Publications Distribution Department...............................16-1 SPZ-8000.........................................................................16-55
PZ 16-11 ASCB.........................................................................16-55
Radar................................................................................16-78 Avionics Standard Communications Bus..........See ASCB
By-pass Forced Standby............................................16-79 Display Units (DU)....................................................16-57
Forced Standby..........................................................16-79 Modification U..........................................................16-66
Radio Control Units.........................................................16-77 Symbol Generators.......................................16-59. See SG
RAIM...................................................................16-23, 16-50 SPZ-8400.........................................................................16-77
Computations.............................................................16-23 Cut-In.........................................................................16-77
Current.......................................................................16-23 Speed Schedules........................................................16-78
Destination.................................................................16-23 Synching Speed Bug to Current Speed......................16-78
Look Ahead...............................................................16-23 SPZ-8400 Conversion........................................................20-9
Pilot Selected.............................................................16-23 Standby Electrical System...................................................1-9
Rainy Weather Ops......................................................19-19 Converters Running.......................................................2-8
Ram Switch........................................................................12-5 DU Status With Main DC Busses Powered...............16-60
Range Figure, Gulfstream................................................18-12 Effect On Avionics........................................................2-8
Rapid Decompression........................................................12-5 Effect on DUs................................................................2-7
Rate Limiting.....................................................................12-3 Generator Output...........................................................2-7
Red X...............................................................................16-62 Inflight Test...................................................................2-8
Altimeter/Airspeed/AOA...........................................16-63 Landing..........................................................................2-7
Altimeter/Airspeed/Vertical Speed/AOA..................16-63 Shutoff Valve Leaking.................................................13-5
Altimeter/Vertical Speed...........................................16-62 Standby Electrical System (ABEX......................................2-6
AOA...........................................................................16-62 Start Up In Icing Conditions..............................................10-2
Red X'ing.........................................................................16-59 Start Valve
Remote Aft Baggage Door Seal Release...........................12-6 No "SVO" Annunciation...............................................7-3
Required Navigation Performance..................................16-20 Supplemental Means Navigation.....................................16-18
Reselecting Bypassed Waypoint.....................................16-34 Supplimental Means Navigation.....................................16-51
Right Bleed Air Bus Change......................................9-3, 20-9 Symbol Generator
RNP.................................................................................16-20 Failures......................................................................16-59
RNP-10......................................................................19-28 Symbol Generators.............................................16-59. See SG
RNP-10 Operations....................................................19-27 Tail De-Icing......................................................................10-4
RNP-5........................................................................19-29 Takeoff
RNP-5 Operations......................................................19-27 Performance Limited...................................................18-4
RNP-10............................................................................16-22 Takeoff Acceleration Check............................................18-12
RTU.................................................................................16-83 Takeoff Computations
Configuration Errors..................................................16-83 Stop/Go........................................................................18-2
Rudder...............................................................................15-4 Takeoff Configuration Warning..........................................4-1
Kick.............................................................................15-4 Takeoff Considerations
Single Rudder Limit Light...........................................15-4 Climb Segments...........................................................18-3
Rudder Pedal Steering Switch................................14-10, 20-7 Second Segment Climb...............................................18-3
Rules of Thumb Tire Speed Limitations................................................18-2
Computer Flight Plans.................................................18-7 TORA/TODA..............................................................18-2
Fuel.....................................................................18-4, 18-6 Takeoff Performance Monitoring....................................18-12
Takeoff.........................................................................18-5 Taxi Light Positive Control Modification.........................20-3
Runway End Offsets........................................................16-35 Taxi Lights...........................................................................3-1
Runway Weight Bearing...................................................18-7 TCAS...............................................................................16-89
RVSM..............................................................................19-23 Terminal Navigation........................................................16-19
ASCs & Pricing.........................................................19-27 TGT.....................................................................................1-2
Expanded Levels........................................................19-26 Third IRS.........................................................................16-18
Safety Relief Valve............................................................12-1 Three-In-One Altimeter.....................................................12-7
Throttle Clamping............................................................16-15
Screen Burn In (DU)....................................................16-57
Thrust Limiter......................................................................7-5
Second Segment Climb.....................................................18-3
Thrust Rev Emer Stow - Power Separation.......................20-4
See) CB....................................................................................
Thrust Reverser Modification............................................20-3
SEP......................................................................................1-9
Thrust Reversers.........................................................1-8, 15-7
Service News.....................................................................19-1
Emergency Stow..........................................................15-8
SG
Lights...........................................................................15-8
Alternate SG Selections.............................................16-59
Lockdown Kit............................................................15-10
Comparision Monitor Annunciations........................16-60
Not Fully Deployed.....................................................15-9
DU Unit Reversion Testing.......................................16-59
On Wheel Spin-up.......................................................15-7
Short Range Fuel Planning..............................................18-11
Pinning.........................................................................15-9
SID Climb Requirements...................................................18-3
Secondary Lock Timer Test........................................15-9
Single Pack Operations........................................................9-3
Starting Engines While Deployed.............................15-11
Gulfstream IV Notes I-11
Revision 2-98 Index

Taxi............................................................................15-11 Valid f............................................................................4-3

Test Requirement.........................................................15-9 Valid Fire Warning........................................................4-3
Throttle Snatch............................................................15-8 Warning Inhibit..............................................................4-1
Uncommanded Deployment........................................15-8 Waypoints
Tire Speed............................................................................1-6 Floaters......................................................................16-10
Tire Speed Limitations......................................................18-2 Weather Web Sites............................................................19-6
TLM.................................................................................16-65 Web Site............................................................................16-1
Data Download..........................................................16-65 Web Sites...........................................................................19-1
Exceedance Warnings................................................16-66 Gulfstream...................................................................19-1
Exceedances...............................................................16-65 Honeywell....................................................................19-4
Parameters Monitored................................................16-65 Hurricane.....................................................................19-6
TLM Exceedance Warnings Jeppesen.......................................................................19-4
Blue Warning.............................................................16-66 Jet Aviation..................................................................19-4
Red Warning..............................................................16-66 Jet Professionals..........................................................19-4
TODA................................................................................18-2 Landings......................................................................19-4
TORA................................................................................18-2 NBAA..........................................................................19-5
Towing.............................................................................14-11 Transport Canada.........................................................19-5
Transformer-Rectifier Unit (TRU)......................................2-5 Volcano........................................................................19-6
Transponder Weather........................................................................19-6
Problems....................................................................16-88 Weigh and Balance
Transponder Cross Source Selector Enabled.....................20-5 SP 1-1
Transport Canada...............................................................19-5 Weight
Trend Limit Monitoring.............................................See TLM Wheel Loading............................................................18-7
Trend Limit Monitoring (TLM)......................................16-65 Weight & Balance.............................................................18-9
TRU.....................................................................................2-5 Aircraft Weight Gain...................................................18-9
Hot Light........................................................................2-5 Weight and Balance.............................................................1-1
Increased Capacity.......................................................20-2 Baseline.........................................................................1-1
Power Source.................................................................2-5 Weight Improving ASCs.................................................18-10
Red Bar Indication.........................................................2-5 Weight Increase to a G-IV SP Equivalent.........................20-4
Upgrade.........................................................................2-5 Weight Increase Upgrades.................................................18-9
TTC......................................................................................7-4 Weight Limitations..............................................................1-1
Turbine Rub.......................................................................7-3 Weighting
Unnecessary Nutcracker Circuit......................................14-15 Nav Source................................................................16-17
Utilility Hydraulic System Wheel Snubbing on Retraction........................................14-17
Armed..........................................................................13-3 Window
Off 13-3 Care..............................................................................17-2
On 13-3 Maintenance.................................................................17-2
Power Sources.............................................................13-3 Windshield Care..........................................................17-2
Utility Hydraulic System...................................................13-2 Windshield
Control Valve..............................................................13-3 Bird Protection.............................................................10-3
Utility Shutoff Valve Leakage...........................................13-5 Heater Latching...........................................................10-3
V1 Windshield Heat................................................................10-3
Balanced......................................................................18-2 Power Sources.............................................................10-3
MAX............................................................................18-1 Windshield Heat Controller Reset.....................................20-3
Min...............................................................................18-1 Windshield Heat Switches.................................................20-5
V1 Selection Criteria.........................................................18-1 Windshield Heat Transient Voltage..................................20-6
Valid Fire Indication............................................................8-1 Windshield Wiper Speed.....................................................1-5
Valid Fire Warning..............................................................4-3 Wing
Ventilating Air Cross Connection.....................................11-1 Leading Edge Sealants...............................................15-12
Vibration....................................................................See EVM WING ANTI-ICE..............................................................10-3
Vibration Sensor................................................................7-10 "L-R WING TEMP LOW"..........................................10-3
VMCG...............................................................................18-6 Wing Tip Flood Light........................................................20-1
VNAV Wingspan.............................................................................1-1
Climb Speed..............................................................16-32 WORLD2........................................................................16-9
Climbs........................................................................16-32 WWW Resources..............................................................19-1
Descents.....................................................................16-32 Y2K Effects on Honeywell Equipment........................16-91
Increased Drag Required...........................................16-33 Yaw Damper......................................................................15-3
Lateral Offsets...........................................................16-50 Dutch Roll....................................................................15-4
Non-Precision Approaches........................................16-26 Fail Indication..............................................................15-4
Offset Waypoints.......................................................16-50 Yaw Damper Inop & Mach Trim Inop................................1-6
Power Annunciation (PFD).......................................16-33 Year 2000 Effects
Power Lever Angle (PLA).........................................16-31
Honeywell Products...............................................16-91
Vertical Deviation......................................................16-31
Zero Fuel Gross Weight Increase to 49,000#....................20-6
Vertical Guidance Technique....................................16-31
Zero Fuel Weight Increase................................................18-9
Volcanic Ash.....................................................................7-10
Zero Fuel Weight Limitation ASC....................................20-9
Voltmeter Sources.............................................................2-22
VSCF System......................................................................2-1
Warning System..................................................................4-1
Engine Fire Warning System.........................................4-2
Takeoff Configuration Warning....................................4-1
Gulfstream IV Notes I-12
Revision 2-98 Index