Analysis

With its ingenious extra girth, the G100’s successor now boasts a best-in-class
cabin cross-section to complement best-in-class cruise performance as well.

By Fred George can carry four passengers 2,700 nm at long- squarely address the model’s shortcomings.
range cruise or dash more than 2,400 nm at As a result, the last G100 aircraft will roll
high-speed cruise with the same payload. off the Tel Aviv assembly line in early 2006.
But unlike the G100, the G150 has a The G150, which was “stretched” in width,
tep aboard Gulfstream’s new G150 transcontinental cabin to match its coast- now boasts 25 percent more cabin volume,

S and you might find it difficult to be-

lieve that it’s a direct descendant of
the super-lean G100, the cruise perform-
to-coast range.
The G100/Astra family was a frequent
first-place finisher in midsize performance
making it much more competitive in the
midsize class. When the first customers re-
ceive their airplanes in third quarter 2006,
ance leader in the midsize class. While and the last-place finisher in sales during its they’ll find cabin comfort more befitting of
closely based on the G100 type design, the 20-year production run. Cabin size was its a Gulfstream product.
G150 offers passengers a full foot more downfall. So, Gulfstream decided to take Some circular cross-section midsize air-
cabin width and 2 inches more height than drastic action after acquiring the Israel craft still boast slightly wider cabins than
its predecessor. Like the G100, the G150 Aircraft Industry (IAI) made jet and the G150’s. But Gulfstream’s newest model

38 Business & Commercial Aviation ■ November 2005 www.AviationNow.com/BCA

 down from the seat back, rather than pop- flight-test aircraft, made its first flight dur-
ping up from the sides of the seat cushion. ing the first week of September. The de-
The seat cushions now measure 22.5 inches velopment program is on track as measured
wide, resulting in five inches more available by hours flown and test cards completed.
width for the hips. The G150 also has the Gulfstream and IAI officials, as a result,
widest floor in the midsize class, helping to are confident they can earn type certifica-
prevent passengers’ feet from falling down tion by first quarter 2006, paving the way
into the dropped aisle. for initial G150 customer deliveries in the
Compared with the G100, the G150’s third quarter. The aircraft’s range and speed
heated aft exterior baggage compartment is targets are being achieved. Its engines are
13 cubic feet larger, now providing 55 cubic meeting required performance, and systems
feet of storage. Forward and aft interior reliability has been excellent, enabling two
closets provide another 25 cubic feet of lug- flight-test missions to be completed practi-
gage storage. Among the G150’s midsize cally every workday. There’s a “road map”
competitors, total luggage and baggage in place to meet weight target goals.
storage volume is exceeded only by the So, when Gulfstream invited B&CA to fly
Citation Sovereign. the G150 in late August, we jumped at the
With all the G150’s apparent assets, it’s opportunity, and on Aug. 31 became the
reasonable to ask why the program is nearly first to fly the aircraft outside of company
a year late. Gulfstream and partner IAI and government pilots. Although it was
launched the G150 program in September only its 66th flight, the G150 more than met
2002, with 50 orders and 50 options placed our expectations.
by NetJets. But in spring 2003 the program
was put on a nine-month hold because of Structure, Systems and
the record downturn in the business aircraft MSG-3 Maintainability
market in the wake of 9/11. The G150 is being certified as a derivative
Following the first sign of recovery in late model that will be added to the type cer-
2003, the G150 development program re- tificate of G100/Westwind Astra. To pre-
sumed full speed ahead. Assembly of the serve the G100’s wing strength margins, the
first of two flight-test aircraft began in April G150’s VMO was reduced from 350 KCAS
2004, and the G150 program is now pro- to 330 KCAS and its MMO was pulled back
ceeding apace. Static testing is complete, in- from 0.87 Mach to 0.85 Mach. The forward
cluding a 160-percent overload of the wing. and aft c.g. limits also were slightly reduced
Serial number 201 was rolled out in January to preserve the G100’s stability and control
2005, and it first flew in May 2005 on a four- characteristics.
hour, 13-minute mission with Ronen Like the G100 and G200 — also made by
Shapira, IAI’s chief pilot, and Yoram Geva, IAI — the G150’s primary airframe is a con-
G150 senior test pilot, at the controls. As of ventional, damage-tolerant, aluminum
Aug. 31, s.n. 201 had flown 230 hours on 67 monocoque structure assembled using tra-
missions. Serial number 202, the second ditional construction processes. Similar to

has a uniquely shaped fuselage with rela-

tively flat sidewalls and an arched top sec-
tion. This design offers 2 inches more
headroom and considerably more shoulder
room for passengers seated in forward- and
aft-facing chairs than most tube-shaped
competitors. The advantage in available
head and shoulder room is even more ap-
parent when one is seated on a side-facing
divan. Few people on the G150’s divan will
be forced to bow their heads as they might
aboard a circular-shaped midsize aircraft.
Other features also contribute to the
G150’s improved cabin environment. The
newest Gulfstream has the G200’s larger
oval cabin windows that let in considerably
more ambient light than the G100’s rectan-
gular transparencies. Passenger seats have The cabin has foldout worktables, remote entertainment system controls and an optional Iridium sat-
been redesigned with armrests that rotate com phone system with a cordless handset.

www.AviationNow.com/BCA Business & Commercial Aviation ■ November 2005 39

Analysis

Gulfstream G150
These graphs are designed to illustrate the performance of the Gulfstream G150 under a variety of range, payload, speed and den-
sity altitude conditions. Do not use these data for flight planning purposes because they are gross approximations of actual aircraft
performance.
Time and Fuel vs. Distance — This graph shows the relationship between distance flown, block time and fuel consumption for the G150
at high-speed and long-range cruise with full tanks and an 800-pound (four-passenger) payload. High-speed cruise is flown at 0.80 Mach
(459 KTAS), and 0.75 Mach (430 KTAS) is used for long-range cruise. Both profiles assume optimum cruise altitude.
Specific Range (Mid-Range Weight, ISA) — This graph shows the relationship between cruise speed and fuel consumption for the G150
at representative cruise altitudes for a 21,000-pound aircraft. The data were supplied by Gulfstream Aerospace performance engi-
neers. B&CA believes Gulfstream’s performance estimates are conservative, based upon our demonstration flight observations.
Range/Payload Profile — The purpose of this graph is to provide simulations of various trips under a variety of payload and two air-
port density altitude conditions, with the goal of flying the longest distance at high-speed cruise. Each of the four payload/range
lines was plotted from multiple data points by Gulfstream’s performance engineers, ending at the maximum range for each payload
condition. The graph illustrates that the G150 can carry four passengers 2,700 miles and eight passengers 2,400 miles at the 430
KTAS long-range cruise speed. The two columns on the left side of the chart illustrate the G150’s FAR Part 25 takeoff field length
performance for sea-level standard day and for B&CA’s 5,000-foot elevation, ISA+20°C airport conditions.

Time and Fuel vs. Distance Specific Range

3,000 0.33
2,700 nm FL 4
50
High-Speed Cruise 2,400 nm 8,874 lb 0.32
FL 4

0.75 Mach Cruise

2,500 8,874 lb 3 0
Long-Range Cruise 2,451 nm 0.31
7,980 lb 0.30
Specific Range (nm/lb)

2,000
1,691 nm FL 37
0.29
Distance (nm)

6,152 lb 0 FL
41
1,500 0.28 0
1,592 nm

Data Source: Gulfstream Aerospace

FL 35
Data Source: Gulfstream Aerospace

5,102 lb 0.27 0 FL
39
1,000 777 nm 0

0.82 Mach Cruise

2,915 lb 0.26
740 nm Conditions: 15,100-lb BOW, 0.25
500 2,531 lb tanks-full payload, zero wind, ISA, Conditions: 21,000-lb cruise
NBAA IFR reserves (200 nm) 0.24
weight, zero wind, ISA
0 0.23
0 1 2 3 4 5 6 7 420 440 460 480
Time (hr) Speed (KTAS)

Range/Payload Profile
Takeoff Field Length (ft) Fuel Burn (lb) 2,531 5,102 7,980 8,874
SL 5,000 ft Gross Takeoff Time (hr) 2 4 6 6+35
ISA ISA+20C Weight (lb)
27,000
Conditions: NBAA IFR reserves (200-nm
5,830 9,750 26,000 alternate), zero wind, ISA, 0.75 Mach cruise
speed, 15,100-lb BOW
d
loa
25,000
x Pay
Ma
d
4,880 7,580 24,000 loa
l b Pay
00-
23,000 1,6 oad
Payl
-lb
800
4,100 6,350 22,000
Data Source: Gulfstream Aerospace

ad
P aylo
21,000 Zero

3,650 5,140 20,000

19,000
0 500 1,000 1,500 2,000 2,500 3,000
Range (nm)

40 Business & Commercial Aviation ■ November 2005 www.AviationNow.com/BCA

the G100, the fuselage is built from cross-
sectional frames, longerons and stressed
skins, but it’s stretched 16 inches aft of the
wing to balance the weight of the wider and
heavier fuselage. The stretch also improves
pitch and yaw stability and control charac-
teristics because the tail is pushed farther
aft, thereby increasing the moment arm.
The G150 shares its first-generation, su-
per-critical wing with the G100 and G200
aircraft. Aerodynamically, it’s closely related
to the wing of current-production Dassault
Falcon aircraft, but it’s smaller in scale. The
wing has 34 degrees of inboard section lead-
ing edge and 25 degrees of outboard lead-
ing edge sweep. The wing is quite flexible
from root to tip, making for a smoother ride
in turbulence. The G150’s long-range cruise
sweet spot is 0.75 Mach, but it’s capable of
speeds up to 0.80 Mach with only a 10-per-
cent increase in fuel consumption. The G150 is intended to carry four passengers with full fuel, so the fare-paying folks shouldn’t want for
legroom in the main cabin.
The main parts of the wing are front and
rear spars, chord-wise ribs and upper/lower cause by that point the static test fixture had Gulfstream and IAI wanted to preserve
stressed skins. Each wing also has a rear run out of travel. the G100’s cruise performance capabilities
subspar that provides the aft attachment Many secondary airframe structures in- in the G150 in spite of its considerably
point for the main landing gear. The as- cluding the radome, gear, baggage com- larger fuselage and even though it uses es-
sembly is quite flexible, producing a soft partment and access doors, plus winglets, sentially the same engines. The G150’s
ride in turbulence. But it’s also very strong. wing leading edges and some flight control BOW also is 565 pounds higher than that
The G150’s wing survived the 160-percent surfaces are built from fiberglass, Kevlar and of the G100. So, drag reduction became an
ultimate overload during static testing be- carbon fiber composites. obsession in Savannah and Tel Aviv from

Gulfstream G150
Price as Equipped . . . . . . . . . . .$13,500,000 Zero Fuel . . . . . . . . . . . . . . . . 17,500/7,938c
BOW . . . . . . . . . . . . . . . . . . . . .15,100/6,849
Characteristics
Max Payload . . . . . . . . . . . . . . . 2,400/1,089
Seating . . . . . . . . . . . . . . . . . . . . . . . . 2+6/8 Useful Load . . . . . . . . . . . . . . . 11,050/5,012 19.4'
Wing Loading . . . . . . . . . . . . . . . . . . . . . 69.0 Executive Payload . . . . . . . . . . . . . 1,200/544 (5.9 m)
Power Loading . . . . . . . . . . . . . . . . . . . . . 2.94
Max Fuel . . . . . . . . . . . . . . . . . 10,250/4,649
Noise (EPNdB) . . . . . . . . . . . . . . . . . . . . . TBD
Payload With Max Fuel . . . . . . . . . . . 800/363
Dimensions (ft/m) Fuel With Max Payload . . . . . . . . 8,650/3,924
Fuel With Executive Payload . . . . 9,850/4,468
External
See Three-View Limits
Internal 55.6' (16.9 m)
MMO . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.850
Length . . . . . . . . . . . . . . . . . . . . . 17.7/5.4
FL/VMO . . . . . . . . . . . . . . . . . . . . FL 300/300
Height . . . . . . . . . . . . . . . . . . . . . . 5.8/1.8
PSI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8
Width (Maximum) . . . . . . . . . . . . . 5.8/1.8

Power Ceilings (ft/m)

Engines . . . . 2 Honeywell TFE731-40AR-200G Certificated . . . . . . . . . . . . . . 45,000/13,716

56.8'
Output (lb) . . . . . . . . . . . . . . . . . . . 4,420 ea. All-Engine Service . . . . . . . . . . . . . . . . . . . TBD (17.3 m)
Flat Rating OAT°C . . . . . . . . . . . . . . ISA+27°C Engine-Out Service . . . . . . . . . . . . . . . . . . TBD
TBO (hr) . . . . . . . . . . . . . . . . . . . . . . . . 3,600 Sea Level Cabin . . . . . . . . . . . 23,000/7,010

Weights (lb/kg) Certification

Max Ramp . . . . . . . . . . . . . . 26,150/11,862 FAR Part 25 . . . . . . . . . . . . . . . . . . . .Pending
Max Takeoff . . . . . . . . . . . . . . 26,000/11,794
Max Landing . . . . . . . . . . . . . . 21,700/9,843 All data preliminary

www.AviationNow.com/BCA Business & Commercial Aviation ■ November 2005 41

Analysis

and taxi lights, instead of upgrading to next-

Cabin Considerations generation HID, xenon plasma units. All
external light mountings have been modi-
No aspect of the G150 is receiving more attention from Gulfstream engineers than the
fied to improve maintenance access.
cabin environment. The G150 will arrive at Gulfstream’s Dallas completion center as Most of the G150’s systems are carried
a green airplane, manufactured by IAI, weighing less than 13,000 pounds. In Dallas, over from the G100 and a few are borrowed
Gulfstream will add the APU, the interior furnishings and exterior paint. The G150 then from the G200. Some systems are modified
will emerge ready for customer delivery. or upgraded for Gulfstream’s newest model.
Six-, seven- and eight-seat cabin seating configurations are available. The seven- The G150’s fuel system, for instance, carries
seat layout, featuring four club seats in the aft cabin, an additional forward-facing chair over the G100 design with the exception of
on the right side and a two-place divan on the left up front, currently is the most pop- a larger aft fuselage bladder tank and elimi-
ular design with customers. Long-life LEDs are used for all interior lights. The cabin nation of fuselage-to-wing tank transfer
has foldout worktables, remote entertainment system controls and an optional Iridium valves. Taking advantage of the 16-inch aft
fuselage stretch, the fuselage bladder has
satcom phone system with a cordless handset.
been enlarged to hold 5,248 pounds of fuel,
The front of the cabin has a coat and crew storage closet, plus a galley on the right almost 400 pounds more than the tank of the
side. The top of the closet has a 15-inch, swing-out video monitor. The galley features G100. There’s no need for a supplemental
two hot liquid containers, a drip tray with overboard drain, large ice drawer and space center fuel extender tank in the baggage
for beverage containers and miniature bottles. A 115 VAC outlet is provided. compartment to achieve maximum range.
Just aft of the entry door on the left side, there’s a second coat closet. There’s a The fuselage fuel tank forms the center
full-width aft lav at the rear of the cabin with externally serviced toilet, vanity and sink, of the 10,250-pound capacity fuel system. A
large wardrobe closet and a second 115 VAC power outlet. An optional belted potty single point pressure refueling (SPPR) re-
seat is available. ceptacle, aft of the right wing root, is used
to replenish the fuselage bladder tank.
There is no fuel quantity preselect feature
on the SPPR panel, but the crew can shut
off pressure refueling with a switch in the
cockpit when the desired fuel level is
achieved. Alternatively, one can use a noz-
zle to refill the fuselage tank through a port
mounted high on the right side of the aft
fuselage.
Fuel from the fuselage tank flows first
into main wing tanks and then into the cen-
ter wing tank in the belly. The fuel usage
sequence essentially is reversed so that main
wing fuel is last to be burned and the c.g.
migrates forward during flight. The up-
shot? If you load the aircraft so that its zero
fuel c.g. is in the middle to forward part of
the envelope, adding full fuel won’t push it
out of the aft c.g. limits.
Jet pumps, using motive flow from the en-
gine-driven fuel pumps, supply fuel to the
engines and move it to the feeder tanks.
Interconnect valves, between the left and
right sides of the fuel system, allow the fuel
level to be balanced, if necessary. DC electric
boost pumps in the feeders supply fuel for
the launch of the program. Gulfstream and G100’s range performance, Gulfstream of- engine start, fuel jettison and defueling. The
IAI engineers completely redesigned the ficials predict confidently. fuel system must be completely drained on
nose of the aircraft, windshields and wing- Stan Dixon, G150 program director, ex- one side to change a fuel boost pump — not
to-fuselage fairings. Details learned from plained that improving systems reliability a maintenance-friendly design feature.
the G450 development program, such as and maintainability has been a prime focus Left and right engine-driven DC starter-
CFD-designed engine pylon fairings, were from program launch. The G150 will be an generators, fitted with long-life brushes and
applied to the G150. MSG 3 aircraft, the product of a two-year maintenance-free ceramic bearings, power
The team also covered control surface refinement process involving customers, the split-buss electrical system. Standard
hinges, installed gap seals, fitted the air- maintenance technicians and designers. equipment includes Honeywell’s well-
craft with flush door openers and bolted Basic scheduled maintenance intervals have proven RE100 APU, which uses the same
on low-drag antennas, among dozens of been extended from 250 hours to 500 hours, starter-generator as the engines. The APU
small improvements. Vortex generators essentially transforming the events into an- is installed with an effective hush kit, it’s ap-
were installed in the inside radius junction nual inspections for most operators. proved for unattended operation, and it can
of the winglets to the wings to prevent LED position lights replace the incan- be operated up to FL 300. Two nickel cad-
high-speed flow separation. The G150, as descent units. Gulfstream, though, chose to mium batteries, mounted below the floor
a result, will preserve almost all of the retain incandescent bulbs for the landing of the aft baggage compartment, supply

42 Business & Commercial Aviation ■ November 2005 www.AviationNow.com/BCA

power for APU and/or engine start. A sep-
arate emergency avionics battery is installed The G150’s Planeview
outboard of the aft coat closet inside the
The G150’s Planeview system is hosted by Rockwell Collins’ Pro Line 21 avionics
cabin. All AC-powered systems have been
eliminated from the G150. However, a 115 aboard the G150. But without looking at the labels on the avionics boxes, it would be
VAC 60 Hz inverter powers outlets in the hard to tell the system is manufactured in Cedar Rapids, Iowa. The G150’s displays bear
cabin for the convenience of passengers. scant resemblance to conventional Pro Line 21 systems. The PFD ADIs, for instance,
The primary flight controls, with the ex- have edge-to-edge sky/earth horizon references. The aircraft symbols have been made
ception of the hydraulically powered larger and shaped more like real airplanes. TCAS resolution advisory guidance cues
ailerons, are manually operated. The G150 have been added to the ADI. Gulfstream’s signature sidewall-mounted cursor control
uses the G200’s artificial control feel unit to device will be installed on each side of the cockpit. FMS and E-chart databases may
simulate aero loads in the roll axis. The be updated in one’s office or on the road by accessing a link to a secure Web site. The
ailerons can be manually actuated in the databases then may be downloaded to USB-compatible memory sticks that plug into
event of a hydraulic failure. The span of the
the aircraft’s avionics system.
elevator servo tab has been increased by 50
percent and it now has variable gearing. Standard equipment includes four 10-by-12-inch portrait configuration displays with
These changes reduce pitch control effort EICAS, dual FMS-6100s with GPS sensors, dual AHRS and a full suite of Pro Line 21
by almost one-half, a welcome change from radios. The basic package also includes a TWR-850 Doppler weather radar, Collins
the hefty pitch forces of the G100/Astra. All TCAS 4000 and Honeywell E-GPWS, plus dual Mode S transponders, ADF radio and a
three control axes use electric motors for radio altimeter, along with HF transceiver with SELCAL, cockpit voice recorder and
trim. An emergency-use-only, high-speed Thales solid-state integrated electronic standby instrument.
aux horizontal stab trim system provides Optional equipment includes dual Honeywell Laseref V units, second ADF and HF ra-
pitch control in the event of an elevator jam. dios and single or dual Collins integrated flight information system boxes with E-charts,
The G150’s left- and right-side aileron con- plus AFIS, L-3 Stormscope and a flight data recorder.
trols may be split for jammed control pro-
Notably, all standard and optional equipment has been tested for functionality and
tection, and the G200-design gust lock is
fitted to it. compatibility aboard an “iron bird” lab mock-up at Rockwell Collins’ facility in Cedar
The slats and flaps are actuated by DC Rapids. In addition, the G150 is being electrically, structurally and electronically pro-
electric motors that drive gear boxes, flex visioned for other popular options, such as an Iridium satcom phone system.
shafts and ballscrew actuators. A large por-
tion of G100 operators’ complaints were
related to problems with the slat and flap
systems, so Gulfstream redesigned both
systems with more robust components and
the G200’s shallower bend geometry in
the flex shafts to increase reliability. At
slow speeds and high angles of attack, the
slats automatically deploy to enhance stall
characteristics.
The G150 is fitted with three-position,
hydraulically powered, eight-panel flight
and ground spoilers. The panels are sub-
stantially stiffer than those of the G100, pre-
venting them from floating up at high speed
and creating drag when they’re stowed. The
eight-panel design allows each panel to de-
ploy to 45 degrees for optimum effective-
ness and yet meet the FAA’s requirement for
roll controllability with one panel malfunc-
tioning. The G100’s four-panel spoilers
were limited to 20 degrees of extension be-
cause of the asymmetric deployment con-
trollability requirement. When used as
flight spoilers, the G150’s inboard half of the changed. Caster has been reduced to im- thority through the rudder pedals. Brawn
panels first are extended. At full deploy- prove directional stability on the ground. for turning the wheels is supplied by hy-
ment, all eight panels extend, creating very The nosewheel strut has been made com- draulic pressure. It’s very smooth and the
effective lift dumping and modest buffet. patible with conventional tow bars, elimi- addition of rudder pedal steering enhances
Automatic rejected takeoff and landing nating the need for a special adapter head. directional control on both runways and
ground lift dump modes are also available. There are four nosegear doors instead of taxiways. The hydraulically powered wheel
The G100’s rugged landing gear is car- two, enabling the aft nosegear doors to brakes, fitted with long-life steel discs, are
ried over to the G150 with a few changes. close fully when the gear is extended, actuated by an anti-skid brake control unit
The main landing gear are moved inboard thereby reducing drag. The G150 gets a in the nose bay, mechanically linked to the
slightly to compensate for the additional new digital nosewheel steering control sys- rudder pedals.
fuselage width. The nosegear geometry, tem with full steering authority through There are two 3,000-psi hydraulic sys-
doors and steering systems have been the tiller and three-degree steering au- tems. The main system, powered by left

www.AviationNow.com/BCA Business & Commercial Aviation ■ November 2005 43

Analysis

G200, modulates cabin altitude. The RE100

APU provides bleed air for ground heating
and air-conditioning prior to engine start.
Its bleed air output also is routed via the
pre-cooler for better air-conditioner per-
formance. Cabin air-conditioning is pro-
vided by a three-wheel air cycle machine,
using higher pressure for increased cooling
capacity. The G450’s temperature controller
is fitted to the G150, but it’s a single-zone
system with partial temperature control in
the cabin.
Dried bleed air also is tapped off the hy-
draulic accumulators to inflate one of two
cabin door seals. The change prevents po-
tentially damaging moisture intrusion and
freezing inside the door seal.
A 77-cubic-foot oxygen bottle, mounted
in the nose below the avionics bay, is stan-
The G150 first flew in May 2005 on a four-hour, 13-minute mission with Ronen Shapira, IAI’s chief pilot,
dard. A 115-cubic-foot bottle, fitting into
and Yoram Geva, G150 senior test pilot, at the controls. the same enclosure, is an option.

and right engine-driven pumps, supplies The G100’s ice protection system is used Flying Impressions
one set of aileron power control units aboard the G150, but low-profile Goodrich For an aircraft that first flew this past May,
(PCUs), landing gear actuators, wheel silver Estane pneumatic boots, instead of s.n. 201 was remarkably mature, even for a
brakes, nosewheel steering and spoilers. black rubber boots, are fitted to the wing derivative. We strapped into the left seat ac-
The aux system, powered by a DC electri- and horizontal stab leading edges. The companied by Shapira in the right seat and
cal pump, supplies the emergency and park- G150’s four glass-faced windshield panes are Scott Evans, G150 chief pilot, as safety pi-
ing brakes, thrust reversers and a second set electrically anti-iced, with bleed air heating lot in the jump seat. Danny Meidan, IAI’s
of aileron PCUs. Hydraulic fluid cooling is available as a backup on the front panels. A senior flight-test engineer, headed up the
accomplished by routing the aileron PCU rain-repellent coating eliminates the need team in the telemetry room. The telemetry
lines through the wing fuel tanks. Both sys- for the G100’s windshield wipers. The crew would record hundreds of perform-
tems are filled with Skydrol phosphate es- probes are electrically heated and engine na- ance parameters during our demonstration
ter fluid. In the event both hydraulic celle inlets are heated by bleed air for ice flight and remain in constant radio contact.
systems fail, the landing gear can be ex- protection. Meidan became a virtual fourth crewmem-
tended with emergency pneumatics, the Engine bleed air, routed through a pre- ber in the cockpit, just as he had during
ailerons revert to manual control, and the cooler in the aft equipment bay, also is used B&CA’s May 1998 IAI Galaxy flight.
wheel brakes may be actuated through the for cabin pressurization, heating and air- Almost immediately, we were impressed
rudder pedals using residual accumulator conditioning. A set-and-forget digital pres- with the G150’s cockpit room, seat comfort
pressure. surization controller, borrowed from the and excellent outside visibility through the
new, larger windows. The reshaped nose
enables the crew to see ahead at relatively
TFE731-40 Engines high pitch attitudes. There’s ample head,
Gulfstream and IAI chose to retain the G100’s 4,250 pounds-thrust Honeywell TFE731- shoulder, elbow and leg room, reminding
40R-200G turbofans aboard the G150 to expedite the development program and save us of the G200 cockpit. The right-side for-
the weight associated with fitting the aircraft with a more powerful engine. For the ward closet, when installed, will provide
G150, Honeywell increased the takeoff thrust by 5 percent to 4,420 pounds of thrust ample nav publication storage for opera-
and raised the ITT limits by means of a “throttle-push” made possible by a DEEC soft- tors who don’t opt for the full electronic
flight bag capability. The overhead panel
ware change. Climb thrust also is in-
design has been changed for improved
creased by 6 to 7 percent and cruise functionality.
thrust is pumped up by 4 percent. Evans and others have completely re-
However, the takeoff thrust flat rating designed the crew chairs for greater comfort
decreases to ISA+10°C from ISA+14°C. and easier operation. The lap belt buckles,
The revised engine is rebadged as the for example, have been moved to the out-
TFE731-40AR-200G model. board strap so that they don’t slam into the
It’s reasonable to ask why Gulfstream center console when the crew exits the cock-
didn’t opt to fit the G150 with pit. The seat cushions, backs and headrests
Honeywell’s new TFE731-50 turbofans. each are independently adjustable in height.
Our second impression was how intuitive
They seemed to be the most logical choice because they produce 4,900 pounds of
the Planeview cockpit appeared. Based
thrust for takeoff with a considerably higher flat rating. The -50 engines also will have upon a Rockwell Collins Pro Line 21 sys-
a 10,000-hour TBO. But they’re also substantially heavier than the -40s, so Gulfstream tem using the four largest general aviation
elected not to use them. displays, Planeview provides far more use-
ful information than is available in the cock-

44 Business & Commercial Aviation ■ November 2005 www.AviationNow.com/BCA

pits of the G100 and current production finding it also to be excellent. Outside air
G200 aircraft. The EICAS, for instance, temperatures averaged 15 degrees above
substantially improves engine and systems standard for most of the climb, sapping en-
status awareness compared with the G100’s gine performance. Using the recommended
clocks, dials and warning lights design. 250 KIAS/0.70 Mach climb schedule, we
The aircraft was connected to ground reached FL 410 about 27 minutes after take-
power, so there was no need to fire up the off and burned 1,100 pounds during the
RE100 APU prior to engine start. Shapira climb.
ran through the prestart checklists and pro- Checking max cruise performance at FL
grammed the twin Rockwell Collins FMS- 410 in ISA+2°C conditions, the aircraft sta-
6100 boxes. We positioned the throttles to bilized at 464 KTAS about four minutes af-
idle, initiated the start sequence and let the ter level off. Fuel burn was 1,430 pph at a
DEECs handle all the start chores. weight of 20,200 pounds, yielding a specific
Our ramp weight was 21,485 pounds, in- range better than 0.32 nm/pound. Whoa.
cluding 6,000 pounds of fuel, enough to fly No wonder Gulfstream officials are confi-
almost 1,500 nm at long-range cruise and dent about their range predictions. That’s
land with NBAA IFR reserves. For the about 15 percent better fuel mileage than
G150, IAI and Gulfstream added the G200- shown on the accompanying Specific Range
style limited-authority nosewheel steering Chart in this report.
through the rudder pedals, while retaining Next, we checked high-speed buffet mar-
Similar to the G100, the fuselage is built from cross-
the tiller for tight turns. Rolling out of the gins. In a gradual wind-up turn, the G150’s sectional frames, longerons and stressed skins.
chocks, the tiller-controlled nosewheel steer- wing didn’t start rumbling until we reached
ing system was quite smooth and precise. 1.65 g’s at FL 410. Then it was time to check ers caused very mild nose-up pitching but
The rudder pedal steering allowed us easily long period pitch stability. We pulled up the p r a c t i c a l l y n o a i r f r a m e b u f f e t i ng .
to track the centerlines of the taxiways. nose to slow the aircraft 10 percent below Extending all the flight spoilers caused a
Braking action was very smooth and yet its 235 KIAS trim speed and let go. The mild nose-down pitching moment, modest
powerful when needed. Shapira extended pitch oscillation cycle was 55 seconds, ac- airframe buffet and very effective lift
the slats, set the flaps to 20 and manually di- cording to Meidan’s telemetry data, and dumping. Descent rates of 12,000 to 13,000
aled in 115 KIAS for V1, 121 KIAS for VR well damped, in large part because of the fpm are possible using full spoilers at red-
and 128 KIAS for V2. Computed one-en- aircraft’s Mach trim system. line airspeeds.
gine-inoperative en route climb speed was We turned off the yaw damper and gen- Leveling at 15,000 feet, we checked pitch
160 KIAS. Ben Gurion International’s ATIS tly pulsed the rudder to excite yaw-roll cou- control forces in a wind-up turn. This ma-
reported altimeter 29.92, OAT of 86°F and pling (Dutch roll). The period was about neuver demonstrated the considerable re-
light winds out of the south. 3.5 seconds per cycle. Even though the yaw duction in pitch control force associated
Once cleared for departure on Runway damper is required at these altitudes, the with the G150’s new elevator servo tab sys-
26, we held the brakes and pushed the G150 exhibited positive yaw-roll damping, tem. It was not difficult to hold back
throttles to the stops. When the engines albeit at a relatively forward c.g. of 26.8 per- enough pressure to sustain a 2.0- to 2.5-g
stabilized at takeoff thrust, we released the cent, according to telemetry. turn at 270 KIAS.
brakes. Directional control was easy be- Descending to 15,000 feet for air work at Full aerodynamic stalls in all configura-
cause of the G150’s new pedal-controlled MMO/VMO, the G150 remained well com- tions cause all smiles aboard the G150, at
nosewheel steering. There was no need to posed with no airframe rumble and just in- least if you’re in the cockpit. The automatic
resort to tiller-controlled NWS. Rotation creased airflow noise in the cockpit. slat extension system was not yet calibrated,
forces at 121 KIAS seemed high and liftoff Extending the inboard pairs of flight spoil- so Shapira extended the high lift devices
was delayed. That’s because we’d not set in
enough nose-up trim. Using telemetry,
Meidan reported rotation forces averaging
48 pounds of pull and a takeoff distance
to 35 feet agl at 3,615 feet. Our takeoff
distance would have been a few hundred
feet shorter if we had set the proper pitch
trim.
Climbing through 400 feet, we turned left
for noise abatement and reduced thrust to
climb. We retracted the flaps and slats at
1,000 feet, noting a mild and gradual pitch
up with flap retraction. The G150’s flap
movement between the 12 degrees and re-
tracted positions has been slowed to lessen
the resulting pitch change and improve pas-
senger comfort. As expected, we raised the
nose a few degrees to compensate for flap
retraction.
On the way up to FL 410, we found con-
trol harmony to be excellent. We checked Similar to the G100, the G150’s fuselage is built from cross-sectional frames, longerons and stressed
short period stability in pitch and roll axes, skins, but it’s stretched 16 inches aft of the wing to balance the weight of the wider and heavier fuselage.

www.AviationNow.com/BCA Business & Commercial Aviation ■ November 2005 45

Analysis

manually for the clean stall as the aircraft in ILS to Runway 12. The G150 has a slip- in all three axes. Shapira bugged our VREF
slowed. At a weight of 19,800 pounds, the pery airframe, so it’s best to anticipate the landing speed at 122 KIAS, based upon us-
aircraft stalled at 111 KIAS. Holding back need to slow well in advance of the ap- ing full slats/40 flaps, 1.28 times stall speed
fully on the yoke causes the aircraft to enter proach. However, it also has a relatively and a weight of 19,100 pounds. Throttle re-
into a gentle pitch rocking motion with vir- high 250-knot slat extension speed, so sponse from the TFE731 engines is excel-
tually no tendency to roll off. Let go, add there’s little need to use the flight spoilers lent, proportionate to throttle movement
thrust and stall recovery is initiated almost for normal approach descents. Extending and easy to modulate.
immediately. Stalls at slats full and flaps 20 the slats, though, does require an increase At 50 feet agl, we commenced a very slow
(normal takeoff configuration) or 40 (land- in pitch attitude to maintain altitude. Most throttle reduction and retarded them to idle
ing configuration) are just as docile. Both of the corresponding nose-down change in at 10 feet during the flare. Although we de-
stalls occurred at 97 KIAS. Holding full aft pitch attitude, caused by extending the first celerated below VREF at that point, we still
on the yoke just causes the onset of gentle 12 degrees of flaps, is mitigated by their had too much speed for touchdown. The
pitch rocking. As soon as pitch attitude is slow extension speed. Extending the flaps aircraft floated for quite some time until the
relaxed and thrust is applied, the aircraft re- to 20 to 40, which occurs at a greater rate, rubber actually contacted the runway. The
covers very quickly. requires less noticeable pitch change to trailing link landing gear proved quite for-
We headed to Ben Gurion International maintain altitude. giving as we settled on to the pavement.
for pattern work and accelerated to near The G150 is stable on approach and very Full thrust reverse is limited to 50 percent
redline airspeed, setting up for a straight- easy to control with pleasant control forces N1 rpm to lessen tail buffeting and improve
passenger comfort. As a result, deceleration
Gulfstream G150 Comparison Profile® without the brakes is modest, at best.
(Percent Relative to Average) Directional control was excellent, thanks to
the three degrees of nosewheel steering au-
Tradeoffs are a reality of aircraft design, although engineers attempt to optimize the
thority that’s available through the rudder
blend of capabilities, performance and passenger comfort. pedals.
B&CA compares the subject aircraft, in this case the Gulfstream G150, to the com- After we rolled onto the parallel taxiway,
posite characteristics of others in its class, computing the percentage differences for Shapira configured the aircraft for takeoff
various parameters in order to portray the aircraft’s relative strengths and weaknesses. with slats/flaps 20 and set V speeds at 111
We also include the absolute value of each parameter, along with the relative ranking, KIAS for V1, 118 KIAS for rotation, 125
for the subject aircraft within the composite group. KIAS for V2 and 155 KIAS for VENR, based
This Comparison Profile compares the G150 to a composite group of four midsize upon a 19,000-pound takeoff weight. This
light jets including it and Bombardier Learjet 60, Cessna Citation Sovereign and would be a simulated one-engine-inopera-
Raytheon Hawker 800XP. The Comparison Profile shows that the G150’s strengths tive takeoff. And, yes, this time we set the
proper pitch trim for takeoff. We positioned
are fuel efficiency, cruise speed and maximum range. Compared to other aircraft in
the aircraft on Runway 26 once again and
class, though, the G150 requires considerably more runway, also as shown on the were cleared for takeoff. This time, though,
Comparison Profile. The chart, however, doesn’t tell the whole story. The G150’s flex- Shapira pulled back the right thrust lever to
ible wing offers a more comfortable ride in rough air than some competitors and idle just after we reached V1 to simulate an
Gulfstream’s product support is tops in its class. engine failure. Moderate rudder pressure
was all that was needed to maintain direc-
90% tional control even though the G150 has no
rudder boost or rudder bias system.
70% Admittedly, the left engine was producing
only 3,800 pounds of installed thrust due to
Above Average

50% the 90°F OAT. We rotated and increased

rudder pressure to maintain balanced flight.
30%
Pitch force at rotation was very pleasant. We
retracted the landing gear with a positive
10%
rate of climb and held V2 until reaching 400
Below Average Average

0%
Gulfstream G150 Price Index feet agl.
-10%
Leveling off about 1,000 feet above the
runway, Ben Gurion Tower cleared us to
-30%
land on Runway 12. We executed a right
-50%
teardrop maneuver to align the aircraft with
the runway centerline. Visibility out the
/1

2
/3
5.8/3
/3

0/3

/2

/2
4
.8/1

/1

09/3

.73/1

/3
.09/2

0/1
3/2

/4

50/4

,700/
/
800/
17.7/

0
5,000
al 8.8

2,142

0.284

0.354
2,400

3,579
0

right cockpit side window was excellent

41,00

e) 4 3
W 0.8

3
5

4
d) 2,1

A) 5,8

C) 9,7
OW 0
TOW 0
Width
eight

ruise)

ng e 2
x Fuel)
Length
ferenti

ude 4

ruise)

ruise)
ayload

from the left seat. We configured the air-

sion)

e Cruis
: MTO

n
g
ad : B

Missio
Payloa
H

(SL, IS

A+20°

in
ad : M

eed C

IFR Ra
Cabin

e Ceil
Cabin

d (Ma

m Mis
d Altit
re Dif

e ed C

nge C

craft at slats/flaps 40, the recommended

Cabin

Max P

-Rang
eight
ful Lo

igh-Sp
0 ft, IS

00-nm
TOFL
(Max

x Paylo

Servic
Payloa

NBAA
Pressu

ertifie

(600-n

ng-Ra
igh-Sp

configuration for an OEI landing. This

ing W

g
— Use

n
Range

o
TAS (H
(5,00

Fuel (6

TAS (L
— Ma

Max C

ge (Lo

time, we reduced thrust to idle at 50 feet agl

x Land

ge (H
TOFL
Ratio

TOFL
Ratio

and let the aircraft slow down a bit before

ic Ran

ic Ran
Block
— Ma

starting the flare. There was much less float,

Specif

Specif
Ratio

but still plenty of residual speed to cushion

the touchdown.
Using thrust reverse on the left engine
helped to decelerate the aircraft during roll-

46 Business & Commercial Aviation ■ November 2005 www.AviationNow.com/BCA

out. We taxied back to the ramp 1.6 hours
after takeoff.
Our conclusions? The G150 is as pleas-
ant to fly by hand as the best of the large-
cabin Gulfstreams, and certainly more
docile in full aerodynamic stalls. The con-
trol forces are well harmonized and it’s quite
stable throughout the flight envelope. It
handles so well and so precisely that it’s
tough to surrender control to the autopilot.
But RVSM airspace leaves us no option; au-
topilot must be used.
Its ground handling manners are just as
refined, with very smooth nosewheel steer-
ing and braking action. Pilots and passen-
gers alike should enjoy the ride aboard the
G150. This is a midsize airplane that emu-
lates the ride of a large-cabin jet.

Price, Value and Utility

Glance at the accompanying Comparison Among the G150’s midsize competitors, total luggage and baggage storage volume is exceeded only
Profile® and you’ll see how the G150 stacks by the Citation Sovereign.
up against its main competitors, the
Bombardier Learjet 60, Cessna Citation more limiting will be Chicago’s Palwaukee ing facilities. Boosting the thrust of the
Sovereign and Raytheon Hawker 800XP. Its airport, with only 5,000 feet available on its TFE731-40 engines by 5 percent reduced
$13.5 million price is within a percent of the longest runway. Popular general aviation flat rating from ISA+14°C to ISA+10°C.
average, so it’s not much of a factor. The airports, such as Santa Ana-Orange County, That’s especially noticeable when departing
G150’s strengths are speed, range and cabin with a 5,700-foot runway; Burbank, with hot-and-high airports.
cross section. Its apparent tanks-full payload 5,801 feet available on Runway 8/26; and Such extreme examples aside, the G150
shortfall relative to the average is deceiving. Carlsbad-Palomar, with 4,900 feet of run- will be quite capable of operating from typ-
If you offload fuel and trade it for payload, way, also will be limiting. Within the ical 4,000-foot general aviation airport run-
the G150 can fly the same payload almost Gulfstream family, as a comparison, only ways on missions up to 2.5 hours in length,
the same distance as the composite average. the G200 needs more runway for a 1,000- assuming standard day conditions. On
Cabin length isn’t one of the G150’s nm trip, according to B&CA’s May 2005 everyday missions, passengers will enjoy
strong suits. At 17.7 feet, it’s the second Purchase Planning Handbook. When flying one of the nicest cabin cross-sections in the
shortest in class. But the G150 is intended the G150 on long-range missions, plan on midsize class, a far cry from the cramped
to carry four passengers with full fuel, so using at least 6,000-foot-long runways, as- quarters of the G100. The enlarged external
the fare-paying folks shouldn’t want for suming sea-level, standard-day conditions. baggage compartment, relative to the G100,
legroom in the main cabin. Operating out of popular high-elevation is a welcome improvement. The standard
Runway performance might be the general aviation airports will be even more RE100 APU will provide much improved
G150’s Achilles’ heel. Departing at MTOW challenging for the G150. Pilots will have air-conditioning performance on the
from Westchester County Airport’s 6,548- to take a close look at runway performance ground and electrical power for au-
foot Runway 16/34, for example, might be when departing Aspen, Eagle, Sun Valley tonomous operations. It’s also very quiet
a challenge on a hot summer day. Even and Telluride, among other mountain land- compared with the G100’s optional
GTC36-150 unit.
Pilots will find this aircraft as nice to fly as
any of its competitors, especially consider-
ing its top-of-class Planeview cockpit.
Flight department managers will appreci-
ate Gulfstream’s product support and the
G150’s MSG-3 maintainability.
Stan Dixon and his team are working
long hours to build reliability into the G150,
so that it will live up to Gulfstream stan-
dards for gas-and-go dependability. The
G100 has attained a 99.75-percent dispatch
rate, Dixon claims. He wants to better that
number for G150 operators.
Overall, the G150 is much more of a
Gulfstream than the G100. Though a de-
rivative of the G100, it’s so much improved
that it’s hard not to believe the G150 is a
clean-sheet design. Look for the G150 to
make its official U.S. debut at the 2006
The G150 is fitted with three-position, hydraulically powered, eight-panel flight and ground spoilers. NBAA Convention in Orlando. B&CA

www.AviationNow.com/BCA Business & Commercial Aviation ■ November 2005 47