IB'EIAYO7a7

MAINTENANCE TRAINING MANUAL

F I R E PROTECTION PART

INTERNATIONAL LEASE FINANCE CORP.

Pa82

TABLE OF CONTENTS PAGE

....
I N T R O D U C T I O N m m m . m . . . . a . . . . . a . . . . . w . m m 2
ENGINE F I R E SYSTEH. . . . . . . . . . . . . . . . . . . . . . . . . . 4
A W F I R E SYSTEH . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
ENGINE F I R E EXTINGUISHING . . . . . . . . . . . . . . . . . . . . . . 29
APU F I R E EXTINGUISHING. . . . . . . . . . . . . . . . . . . . . . . . 34

NOTICE

T H I S MANUAL HAS BEEN PREPARED FOR AIRPLANE SYSTEMS

TRAINING. I T WILL NOT BE REVISED AND DOES NOT AMEND
OR SUPERSEDE INFORMATION CONTAINED I N APPLICABLE
GOVERNMENTAL REGULATIONS AND BOEING'S APPLICABLE
SERVICE BULLETINS, MAINTENANCE MANUALS, OVERHAUL
HANUALS AND WRITTEN INSTRUCTION,

PUBLISHED BY MAINTENANCE T R A I N I N G
BOEING COMMERCIAL AIRPLANES

059* PAGE 001

DEC 15/88 26.00.001
 am!!zt!,G
7z7
MAINTENANCE 1RAINING RANUAL

INTRODUCTIQN

FIRE SYSTEM

1. Purpose
The f i r e system i s used for detection, indication and extinguishing o f a f i r e
i n the engine compartment, APU compartment, and Fire detection and indication
f o r the main wheel well.
2. System Description
The system consists of detection, indication, controls and extinguishing
bottles.
GENERAL DESCRIPTION

1. Genera 1 Component Location

The detectors are located on each engine, AFU and i n the main wheel well.
The control c i r c u i t s are i n the Engine and APU Fire Detection Accessory Unit
(R279) and Compartment Overheat Accessory Unit CM237) located i n the
electronic equipment compartment. I n the f l i g h t compartment, indication i s
on the l i g h t shield (panel P?), engine and APU Fire Control Module (panel P8)
and i n the Aural Warning Devices Box (R315).
The APU ground control panel (P28) and warning horn are located i n the main
wheel well. The engine f i r e extinguisher bottles are i n the main uheel well
and the APU b o t t l e i s forward of the APU compartment.
2. General Operation
When a high temperature i s sensed by a detector, i t i s indicated by amber
lights (engine overheat) or red l i g h t s and a b e l l (engine, APU o r wheel well
fire). I n addition, a red l i g h t and horn operate f o r the APU whi l e on the
ground. - The extinguishing bottles are discharged from the f l i g h t compartment
and the APU b o t t l e can also be discharged from the APU panel i n the wheel
well.

PAGE 002 001

26.00.002 JAN 24/85
 rnrnElN4 7s7
HAINTENANCE TRAINING MANUAL

c-\ \ APU GROUND CONTROL

PANEL AND
I-\
/
/
I

\\ \\
WARNING HORN \, ,/ / ,
// /
/ I

CAPTAIN'S AND \\ \\ WHEEL WELL FIRE FIRE

FIRST OFFICER'S \ \DETECTOR DETECTCIRS
LIGHT SHIELD \

1 AURAL YARNING
\
\, _ L-2 -------
-\
-\

---7

APU EXTINGUISHER BOTf LE

ENGINE EXTINGUISHER BOTTLES

--
!E DETECTORS

F I R E SYSTEM

i 001 PAGE 003

JAN 01/84 26.00.003
 SHEING 7Z7
MAINTENANCE TRAINING MANUAL

INTRODUCTION

ENGINE F I R E SYSTEH

1. Purpose

The engine f i r e system senses high temperature i n the engine compartment and
provides the corresponding alarms.

2. System Description

The system consists of overheat and f i r e detectors, control and t e s t

circuits, amber and red warning l i g h t s and an alarm b e l l .

GENERAL DESCRIPTION

1. Genera1 Compartment Location

The overheat and f i r e detectors are located on the fan case and core section
o f the engine. The control and t e s t c i r c u i t s are i n the Engine and APU F i r e
Detection Accessory Unit (H279) i n the electronic equipment compartment. I n
the f l i g h t compartment are the warning l i g h t s and the f i r e alarm b e l l .

2. General Operation

When the detector senses a high temperature, a signal i s sent t o the control
circuits, which allow amber l i g h t s (overheat) o r red l i g h t s and a b e l l t o
operate ( f i r e ) .

PAGE 004 001

26.11.001 JAN 01/84
 H',EiNrn7a7
HAINTENANCE TRAINING MANUAL

CAPTAIN'S AND
FIRST OFFICER'S
LIGHT SHIELD

AND
ENGINE AND A W F I R E ENGINE OVERHEAT
'IRE 'ONTRoL DETECTION ACCESSORY UNIT AND F I R E DETECTORS
NODULE

ENGINE F I R E SYSTEM

JI 001 PAGE 005

JAN 01/84 26.11.002
 BmEI!ME7a7
RAINTENANCE TRAINING MANUAL

COMPONENT FUNCTIONAL DESCRIPTION

ENGINE OVERHEAT AND FIRE DETECTOR

1. Purpose

The overheat and f i r e detector senses abnormal temperatures i n the engine

compartment.

2. Location

Three sections of the detector are mounted around the fan case (the accessory
compartment) and one section i s mounted on the high pressure turbine case
(core compartment).

3. Physical Description

A detector consists o f two i d e n t i c a l sensing elements attached t o a support

tube by quick-release mounting clamps. Each sensing element i s a r e s i s t o r
network, w i t h resistance varying as a funci ton o f temperature.

4. Power

The power supply f o r the detector operation i s from the Engine and APU F i r e
Detection Accessory Unit, (M279).

5. Operation

As the temperature o f the element increases, resistance decreases. When

resistance Lowers t o the f i r s t alarm setting, an overheat signal i s sent t o
the c o n t r o l card. When resistance continues t o lower t o the second setting,
a f i r e signal i s sent t o the c o n t r o l card.

PAGE 006 002

26.11 -003 DEC 10/85
 LEFT UPPER
f AN
,
HQ!E/!M&7S7
RAINTENANCE TRAINING MANUAL

FIREUALL DETECTOR
TOP OF ENGINE
{

ORE CONPARTMENT

LOWER FAN
DETECTOR /

-A

TUBE

.PIN
RECEPTACLE

\ SOCKET
-SOCKET RECEPTACLE
RECEPTACLE

A - A

ENGINE FIRE DETECTOR

(TYPICAL)

ENGINE OVERHEAT AND F I R E DETECTOR

5 002 PAGE 007

APR 25/86 26.11.004
 7a7
mm!!!!1!W44
MAINTENANCE TRAINING MANUAL

GOFIPONENT FUNCTIONAL DESCRIPTION

ENGINE (AND APU) F I R E DETECTION ACCESSORY UNIT (M279)

1. Purpose

The control c i r c u i t s f o r the engine overheat and f i r e indication, f a u l t

indication, alarm cutout and t e s t are located i n the Engine and APU Fire
Detection Accessory Unit (M279).

2. Location

The Engine and APU Fire Detection Accessory Unit i s Located i n the electronic
equipment compartment.

3. Physical Description

On the frcnt of the u n i t are four amber Lights for detectors A and B for the
two engines. Below the l i g h t s i s a FAULTIINOP test switch.

4. Power

The power supply f o r the c i r c u i t s and l i g h t s i s 28 v o l t dc from the battery

bus.

5. Operation

Under normal operating conditions, the four amber Lights are extinguished.
Illumination of the particular amber l i g h t indicates a f a u l t i n the
corresponding detector loop.

6. Haintenance Practices

Pushing the test switch simulates a f a u l t i n the detection circuits, this i s

indicated by illumination of the four amber lights. I f the l i g h t does not
illuminate during the test, the corresponding c i r c u i t card has t o be
replaced. The test switch u i l l also illuminate the f a u l t Lights on the P8-1
pane1.

7. Lamp Test

The four amber Lights are press t o t e s t type.

PAGE 008 001

26.11.005 APR 25/86
 mmEIAr& 7a7
HAINTENANCE TRAINING MANUAL

ELECTRONIC
EQUIPMENT
RACK E3

-ENGINE AND AW FIRE

DETECTION ACCESSORY

Illumination of the particular amber light indicates a

fault in the corresponding detector loop.
all lights are press to test
type.
I BETECTOR S V S T a
I W I W TEST I

Pushing the test switch simulates a fault in the detection circuits, this is
indicated by illumination of the four amber lights.

ENGINE (AND APU) FIRE

DETECTION ACCESSORY UNIT

ENGINE (AND APU) F I R E DETECTION ACCESSORY U N I T (M279)

PAGE 009
26.11.006
 BMEIArG 7-
MAINTENANCE TRAINING MANUAL

COMPONENT FUNCTIONAL DESCRIPTION

ENGINE OVERHEAT AND FIRE INDICATION

1. Purpose

The engine overheat i n d i c a t i o n i s by amber lights, f i r e i n d i c a t i o n i s by red

l i g h t s and a f i r e alarm b e l l . A f a u l t i n the engine detecror i s indicated by
amber l i g h t s .

2. Location

I n the f l i g h t compartment are the amber and red l i g h t s on the glareshield

(P7) and Engine and AW F i r e Control Module (Pa), the alarm b e l l i s i n the
Aural Uarning Devices Box (M3151,

3. Physical Description

On the P7 panel are two MASTER CAUTION and OVHTIDET annunciator amber l i g h t s
and tuo FIRE WARN red Lights which also act as alarm cutout switches.

On the P8 panel are two amber ENG OVERHEAT lights, two red f i r e handles, and
an amber FAULT light, b e l l cutout switch, t e s t switch and tuo loop selector
switches.

4. Operation

When an OVERHEAT i s sensed i n the fan o r core compartment, the ENGINE

OVLRHEAT, MASTER CAUTION and OVHTIDET amber Lights i1luminate. Upon cooling
down the Lights extinguish. When a f i r e i s sensed i n the fan o r core
compartment, the engine f i r e handle and FIRE WARN red lights, illuminate and
the b e l l operates. Upon cooling down, the l i g h t s extinguish and the b e l l
stops. Pushing e i t h e r FIRE WARN l i g h t o r the b e l l cutout switch,
extinguishes the F I R E WARN l i g h t s on the P7 panel and stops the b e l l .

The t e s t switch, when placed t o the OVHT/FIRE position, checks the detector
validity, allowing the amber and red l i g h t s t o i l l u m i n a t e and the b e l l t o
operate. With the t e s t switch i n the FAULT/INOP position, a f a u l t i s
simulated, allowing the amber FAULT l i g h t t o i l l u m i n a t e and i l l u m i n a t i n g the
amber f a u l t l i g h t s on module 279.

I l l u m i n a t i o n o f the FAULT l i g h t indicates t h a t both loops (A and B) o r the

Loop (A o r B) selected by the OVHT DET switch i s faulted.

PAGE 010 001

26.11.007 APR 25/86
 BrP!I!MrnF a 7
MAINTENANCE TRAINING MANUAL

P7 GLARESHIELD

P8 ENGINE AND APU F I R E CONTROL MODULE

ENGINE OVERHEAT AND F I R E I N D I C A T I O N

001 PAGE 011

JAN 01/84 26.11.008
 BnElArB 7a7
RAINTENANCE TRAINING MANUAL

ENGINE OVERHEAT AND FIRE DETECTION

Norma 1 Sequence

Standby Condi t ion

During the standby condition, the detectors receive regulated dc voltage.

Yith a large voltage drop across the detector, the result i s no output
from the detection cards and normal indication i n the f l i g h t compartment.

Overheat Condition

A t 350°F (fan comcartment) o r 650°F (core compartment) ,

the loop
resistance decreases, creating an overheat signal i n the detection card.
Logic outputs from the card unlock the f i r e handle and illuminate the
amber ENG OVERHEAT l i g h t .

Fire Condition

A t 530°F (fan compartment) or 850°F (core compartment), the loop

resistance further decreases, creating a f i r e signal i n the detection
card. Logic outputs from the card unlock and illuminate the f i r e handle,
illuminate the two red F I R E WARN l i g h t s and the b e l l operates. Pressing
either F I R E WARN l i g h t o r BELL CUTOUT silences the b e l l and extinguishes
the F I R E WARN Lights.

Fau1t Condi t ion

I f a f a u l t i s present because o f a short c i r c u i t the resistance decreases

rapidly, creating a f a u l t signal i n the detection card. Logic outputs
from the card illuminate the FAULT l i g h t i n the f l i g h t compartment and
corresponding detector l i g h t s on the f r o n t of the Engine and AW F i r e
Detection Accessory Unit 04279).

--
NOTE: The above conditions are with the OVHT DET switch i n the NORMAL
position (A and B). C i r c u i t operation i s similar f o r loop A or
loop B as selected by the OVHT DET switch.

PAGE 012 002

26.11.009 MAR 30/88
 B&!!IND7a7
MAINTENAMCE T R A I N I N G MAMUAL

MAINTENANCE PRACTICES

TEST

OVHT/FIRE Position

Placing the t e s t switch t o the OVHTlFIRE p o s i t i o n checks the i n t e g r i t y uf the

overheat and f i r e detectors. I f the t e s t i s s a t i s f a c t o r y amber EMG OVERHEAT,
red FIRE YARN and f i r e handles i l l u m i n a t e and the b e l t oeprates.

FAULT/INOP Position

Placing the t e s t switch t o the FAULT/INOP p o s i t i o n checks the f a u t t d?tection

c i r c u i t s . I f the t e s t i s s a t i s f a c t o r y the amber FAULT l i g h t illuminates i n
the f l i g h t compartment and four amber l i g h t s i l t u a i n a t e on the front o f the
Engine end AW F i r e Detection Accessory W i t (R79).

001 PAGE 013

JAN 01/84 26.t1.010

L
 1
ma!/#- 7a7
MAIHTEMAMCE TRAIHIMG HWUAL

F I R S T GATE ENERGIZED
@ D I Z N L E S THE OTHER

W I M E CORE O V H T f F I R E
DETECTOR
11279 ENGINE AND AW F I R E DETECTION ACCESSORY W I T

ENGINE OVERHEAT AND F I R E D E T E C T I O N

PAGE 014 OOt

26.1 1.013 MAR 30/88
 INTRODUCTION

APU F I R E SYSTEM

1. Purpose

The APU f i r e system senses high temperatures i n the AW compartment and

provides the corresponding alarms.

2. System Description

The system consists of f i r e detection, c o n t r o l and t e s t circuits, red warning

l i g h t s and an a l a m b e l l .

GENERAL DESCRIPTION

1. General Component Location

The f i r e detectors are located i n the AW coqartment. The c o n t r o l and t e s t

c i r c u i t s are i n the Engine and AW Fire Detection Accessory U n i t (HZ791 i n
the electronic equipment compartment. The warning Lights and the f i r e a l a m
b e l l are located i n the fhight compartment. A ground control paneL i s i n the
main wheel well.

2. General Operation

When the detector senses a high temperature, a signat i s sent t o the control
circuits, which a l t o u red lights, belk and horn t o operate.

PAGE 016 001

26.15.001 JAN 01184
 BCtEINm 7a7
MAINTENANCE TRAINING MANUAL

\ APU GROUND CONTROL ,\ \b,' /

'\ \
'
CAPTAIN S AND
FIRST OFFICER'S
LIGHT SHIELD
'
\

\\
\
\\
PANEL AND
WARNING HORN
\ -4
,' ,
,'

ENGINE AND APU F I R E

F I R E CONTROL
DETECTION ACCESSORY U N I T
MODULE

APU F I R E SYSTEM

" 001 PAGE 017

8 JAN 01184 26.15.002
 mmEI!ln 7a7
MAINTENANCE TRAINING MANUAL

SOHPONENT FUNCTIONAL DESCRIPTION

APU FIRE DETECTOR

1. Purpose

The f ire detector senses abnoraa 1 temperatures i n the APU compartment.

2. Location

One section o f the detector i s mounted on the bottom o f the APU engine, one
on the outside Leading edge o f the exhaust pipelmuffler and one on the
outside of the exhaust pipe heat shield.

3. Physicai Description

A detector consists o f two i d e n t i c a l sensing elements attached t o a support

tube by quick-release mounting clamps. Each sensing element i s a r e s i s t o r
network, w i t h resistance varying as a function of temperature.

4. Power

The power supply f o r the detector operation i s from the Engine and APU F i r e
Detection Accessory Unit, (M279).

5. Operation

As the temperature o f the element increases, resistance decreases. When

resistance lowers t o the alarm setting, a f i r e signal i s sent t o the c o n t r o l
card.

PAGE 018 002

26.15.003 DEC 05/85
 H~El#C7-
MAINTENANCE TRAINING MANUAL

APU F I R E DETECTOR

E 002 PAGE 019

DEC 05/85 26.15.004
 BNEI!M# 7-
MAINTENANCE TRAINING MANUAL

COMPONEhT FUNCTIONAL DESCRIPTION

(ENGINE AND) APU FIRE DETECTION ACCESSORY UNIT N279

1. Purpose

The control c i r c u i t s f o r the APU f i r e indication, f a u l t indication, alarm

cutout and test are located i n the Engine and AW Fire Detection Accessory
Unit (H279).

2. Location
The Engine and APU Fire Detection Accessory Unit i s Located i n the electronic
equipment compartment.

3. Physical Description

On the front of the u n i t i s an amber Light and a FAULTIINOP t e s t switch.

The power supply f o r the c i r c u i t and l i g h t i s 28 v o l t dc from the battery

bus.

5. Operation

Under normal operating conditions, the amber l i g h t i s extinguisted.

Illumination of the amber l i g h t indicates a f a u l t i n the detector loop.

6. Maintenance Practices

Pushing the test switch simulates a f a u l t in the detection circuit, t h i s i s

indicated by illumination o f the amber light. I f the l i g h t does not
illuminate during the test, the c i r c u i t card has t o be replaced. The t e s t
switch w i l l also illuminate the f a u l t l i g h t on the P8-1 panel.

7. Lamp Test

The amber l i g h t i s pressed t o test type.

PAGE 020 001

26.15.005 APR 25/86
 mm!ElAIn7a7
MAINTENANCE TRAINING MANUAL

ENGINE AND APU FIRE

DETECTION ACCESSORY

I DETECTOR SYSTEM
FAULTIlllOP TEST
I

(ENGINE AND) APU F I R E

DETECTION ACCESSORY UNIT

(ENGINE AND) APU F I R E D E T E C T I O N ACCESSORY UNIT tM279)

" 001 PAGE 021

t
= JAN 01/84 26.15.006
 BII1FlAYrlP 7s7
MAINTENANCE TRAINING MANUAL

COMPONENT FUNCTIONAL DESCRIPTION

APU F I R E INDICATION
1. Purpose
The APU i n d i c a t i o n i s by means of red 1Sghts and a f i r e alarm b e l l . A fault
i n the APU detector i s indicated by amber lights.

I n the f l i g h t compartment are the amber and red l i g h t s on the glareshield

(P7) and Engine and APU F i r e Control Module (P81, the alarm b e l l i s i n the
Aural Warning Devices Box (M315).
3. Physical Description
On the P7 panel are two MASTER CAUTION and OVHTIDET annunciator amber l i g h t s
and two F I R E WARN red l i g h t s which also a c t as alarm cutout switches.
On the P8 panel i s an amber APU DET INOP light, red f i r e handle, b e l l cutout
switch and a t e s t switch.
4. Operation
When the temperature o f 400°F on the AW, 750°F on the exhaust pipe o r 360°F
on the heat s h i e l d i s sensed, the APU f i r e handle and FIRE WARN red l i g h t s
i l l u m i n a t e and the b e l l sounds. Pushing e i t h e r FIRE WARN l i g h t o r the b e l l
cutout switch, extinguishes FIRE YARN l i g h t s and stops the bell.
The t e s t switch, uhen placed t o the OVHTIFIRE position, checks the detector
v a l i d i t y , allowing the red Lights t o illuminate and the b e l l t o operate.
With the t e s t switch i n the FAULTIINOP position, a f a u l t i s simulated,
allowing the amber APU DET INOP l i g h t t o illuminate and i l l u m i n a t i n g the
amber f a u l t l i g h t s on the modale 279.
I l l u i n i n a t i o n o f the APU DET INOP l i g h t indicates a f a u l t i n the detecting
system.

PAGE 022 001

26.15.007 APR 25/86
 ~ ~ E I N7a
H7
MAINTENANCE TRAINING HANUAL

P? GLARESHIELD

P8 ENGINE AND APU FIRE CONTROL MODULE

APU F I R E I N D I C A T I O N

001 PAGE 023

f JAN 01/84 26.15.008
 HNE/NB 7S7
MAINTENANCE TRAINING MANUAL

EOMPONENT FUNCTIONAL DESCRI PTTON

APU GROUND CONTROL PANEL

Purpose

The APU ground control panel provides visual and aural f i r e warning and
extinguisher operation from the ground. The panel can a l s o be used for
stopping the APU i n an emergency.

Location

The control panel i s located on the a f t bulkhead o f the r i g h t main wheel

well.

Physical Description

The panel consists of a red f i r e warning light, f i r e horn, horn cutout

switch, f i r e handle and an extinguisher discharge switch.

Operation

When a f i r e i s detected i n the APU, the'horn and l i g h t w i l l operate

a l t e r n a t e l y and the APU shuts down automatically. Pushing the horn cutout
switch stops the horn sounding and the red l i g h t remains illuminated.

When the f i r e handle i s pulled, the APU shuts down ( i f not already shut down
automatically by f i r e detection) and the extinguisher system i s armed. The
f i r e b o t t l e ismdischarged i n t o the APU shroud by using the f i r e extinguisher
switch.

PAGE 024 001

26.15.009 NOV 30184
 B@!',Nm7a7
MAINTENANCE TRAINING RANUAL

APu GROUND CONTROL n

APU F I R E
WARNING HORN
I

CUTOUT SWITCH

APU F I R E
WARNING LIGHT CONTROL HANDLE

APU GROUND CONTROL PANEL

001 PAGE 025

APR 25/86 26.15.010
 BUEIIYG 7S7
MAINTENANCE TRAINING MANUAL

OPERATION

APU F I R E DETECTION SYSTEM

Norma 1 Sequence

Standby Condition

During the standby condition, the detectors receive regulated dc power.

With no voltage drop across the detector the result i s no input t o the
detection card and hence normal indication i n the f l i g h t compartment.

Fire Condition

A t 400°F, 7S0°F o r 360°F (depending on detector location) the loop

resistance decreases, allowing the f i r e signal t o the detection card.
Logic outputs from the card unlock and illuminate the f i r e handle,
illuminate the two red F I R E WARN lights, the b e l l operates and the l i g h t
and horn i n the wheel u e l l operate. Horn operates only on the ground.
Pushing either FIRE WARN light, the b e l l cutout switch or horn cutout
switch, extinguishes the two F I R E WARN l i g h t s and silences the b e l l and
horn. The l i g h t i n wheel well remains illuminated.

Fau1t Condi t ion

I f a f a u l t i s present due t o a short c i r c u i t , the resistance decreases

rapidly allowing the f a u l t signal to the detection card. Logic output
from the card illuminates APU DET INOP l i g h t i n the f l i g h t colnpartment
and corresponding detector l i g h t on the f r o n t o f the Engine and APU F i r e
Detection Accessory Unit (H279).

MAINTCNANCE PRACTICES

Test

OVHTIFIRE Condition

Placing the t e s t switch t o the OVHT/FIRE position checks the i n t e g r i t y of

the f i r e detectors. I f the test i s satisfactory, red F I R E WARN and f i r e
handles illuminate and the b e l l and horn operate.

FAULTIINOP Posi t i o n

Placing the t e s t switch t o the FAULTIINOP position checks the f a u l t

detection circuits. I f the test i s satisfactory, the amber APU DET INOP
l i g h t illuminates i n the f l i g h t compartment and the amber l i g h t
illuminates on the Engine and APU Fire Detection Accessory Unit (M279).

PAGE 026 002

26.15.011 NOV 30184
 BIIEING 7S7
MAINTEHAHCE TRAINING MANUAL

YELL)

I)

11278 MISC SOLID STATE

SYITCW IWDULE

E l l LDG BEAR SHELF

APU F I R E DETECTION SYSTEM

PAGE 027
26.15.014
 BrnE.Arrn 7a7
MAINTEWANCE TRAIMING MANUAL

UALTER KIDDE
COWTROL W I T
CW79)

- 1 H O a L S T M D B I CONDITION

UALTER CW79) (Pel> (P8-11 (P7) (P7) AW

TIODE AAl APU FIRE FIRE CAUT SHUT
CONTROL W I T IMOP IHOP WDLE YAM LT 4 Wm
(llZTP) LT LT LT LT 1 WiITI
BELL DET LT

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F I E
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(lQ.79) <f%-1) (Pa-1) iPT> (P71 IPU

hW AflJ FIRE F I E UUT SHn
IW IMP WDLE YAM LT L Dam
LT LT LT LT 1 OYHTI
BELL BET LT

mw
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FUILT SHORT
F W L T WEN
R I R FAILURE

W L D EITHER TME F M k T TEST SUITEM OW W?79 OR

+TEST s u I T c H us-1) TO -FMTIIW(OPH POSITION -----I
(IIZ79) <Pel> (Ps-1) (P7) (P7) APU
AFU APJ F I E FIRE ChUT SHUT
Imp I m p n m YARN LT L wm
LT LT LT CT L DYnrl
BUL PET U

YOI
FIRE
FAULT SHORT
FAULT OPE#
WR FAILURE

APU F I R E DETECTION - L O G I C TABLE

PAGE 028
26.t5.015
 SHEiNG 7S7
MAINTENANCE TRAINING MANUAL

INTRODUCTION

ENGINE FIRE EXTINGUISHING

1. Purpose

The engine f i r e extinguishing system, upon activation, w i l l f l o o d the engine

compartment w i t h an i n e r t gas and smother the f i r e .

2. System Description

The system consists o f an Engine and APU F i r e Control Nodule (P8)and two
extinguisher bottles.

GENERAL DESCRIPTION

1. General Component Locations

The two engine extinguisher b o t t l e s are located i n the upper l e f t a f t comer

o f the main l e f t wheel well.

2. General Operation

The engine f i r e extinguisher b o t t l e s are discharged from the f l i g h t

compartment. E i t h e r o r both b o t t l e s can be discharged t o the same engine.

,----
-_
-------*-----'
--,

ENGINE AND APU

FIRE CONTROL

ENGINE F I R E E X T I N G U I S H I N G

PAGE 029
3 JAN 01/84 26.21.001
r
 mm!!!!i!mG
7n7
RAINTENANCE TRAINING MANUAL

gOMPONENT FUNCTIONAL DESCRIPTION

ENGINE FIRE EXTINGUISHER BOTTLES

1. Purpose
The f i r e extinguisher b o t t l e s contain the extinguishing agent f o r f i r e
suppression i n the engine compartments.
2. Location

The two b o t t l e s are located i n the upper a f t l e f t corner o f the l e f t main

wheel we11.
3. Physical Description
Each spherical b o t t l e contains the extinguishing agent pressurized with
nitrogen t o 800 p s i a t 70°F. Mounted on the b o t t l e are a pressure gage and
switch, f u s i b l e plug with red disc (safety r e l i e f port) and two discharge
ports with dual cartridges.

4. Power
Power f o r the cartridge operation i s 28 v o l t dc from the hot b a t t e r y bus.
5. Operation
The b o t t l e i s discharged by energizing the cartridge, which ruptures a disc
and the extinguishing agent flows from the b o t t l e t o the engine compartment.
Either o r both b o t t l e s can be discharged t o the same engine.
Ifthe b o t t l e temperature increases t o approximately 266OF, the b o t t l e i s
discharged i n t o the wheel well, blowing out the red disc.

6. Maintenance Practices
When the b o t t l e has been discharged, o r the pressure i s Low, the b o t t l e must
t o be replaced. B o t t l e replacement requires disconnecting e l e c t r i c a l plugs
and discharge tubing.

PAGE 030 001

26.21.002 JAN 01/84
 BHEIArrrG*7S7
MAINTENANCE TRAINING MANUAL

I AFT F I R E BOTTLE
LABELED "R" I N FLT DK I I FWD FIRE BOTTLE
LABELED "L" I N FLT DK I

SAFETY 14
RELIEF
4
PORT 1

(RUPTURE D I S C )

ENGINE F I R E E X T I N G U I S H E R BOTTLES

" 002 PAGE 031

FEB 10186 26.21.003
 BflEIkrH 7a7
MAINTENANCE TRAINING MANUAL

OPERATION

ENGINE F I R E EXTINGUISHING SYSTER

Operation Sequence
When an overheat o r f i r e has been detected the engine f i r e handle
automatically unlocks. It can also be unlocked by a manual override plunger
under the handle. P u l l i n g the f i r e handle closes the fuel shut o f f valve,
the engine bleed a i r valve, and the hydraulic shut o f f valve, disarms the
hydraulic low pressure indicators, disarms t h r u s t reverser and t r i p s the
generator.
Rotating the f i r e handle l e f t o r right, allow 28 v o l t dc power t o the dual
cartridge and the selected ( l e f t o r r i g h t ) b o t t l e discharges. I f the f i r e
has not been extinguished, r o t a t i n g the f i r e handle i n the opposite d i r e c t i o n
discharges the second b o t t l e t o the same engine.
When b o t t l e pressure decreases t o 250 psi, a pressure switch closes and an
amber BOTTLE DISCHARGED l i g h t illuminates on P8 panel
MAINTENANCE PRACTICES

Test
Using the extinguisher t e s t switch on P8 panel checks the c o n t i n u i t y through
the cartridges.
Placing the switch t o p o s i t i o n 1, 28 v o l t dc power closes four switches i n
the b i l a t e r a l switch card. Power passes through the switches t o No. 1 double
cartridges on each bottle. I f grounds are present through the cartridges,
the logic gates provide outputs t o bias the transistors and two green l i g h t s
L BOTTLE and R BDTTLE, illuminate. S i m i l a r t e s t s are performed f o r the No. 2
cartridges using the t e s t switch t o p o s i t i o n 2.
I f the l i g h t does not illuminate during test, i t indicates that e i t h e r one o r
both squibs i n the dual cartridge assembly have failed.

PAGE 032 001

26.21.004 JAN 27/86
 BDEIAr17 737
MAINTENANCE T R A I H I N 6 MANUAL

E N G I N E F I R E E X T I N G U I S H I N G SYSTEM

: 001 PAGE 033

i MAR 30/88 26.21 .DO7
 BIIEIkrO la7
MIMTENANCE T R A I M I N G MANUAL

INTRODUCTION

APU FIRE EXTINGUISHING

1. Purpose

The APU f i r e extinguishing system, upon activation, w i l l f l d the AW shroud

with an i n e r t gas and smothers the f i r e .

2. System Description

The system consists o f an extinguisher bottle, Engine and APU F i r e Control

M u t e (Pa), and AW Ground Control Panel (P28).

GENERAL DESCRIPTIOM

1. General Eo~ponentLocation

The AW extinguisher b o t t l e i s located i n the fuselage forward of the AW

compartment. Panel Pi3 i s Located i n the f l i g h t compartment and panet P28 i s
located i n the main wheel well.

2. General Operation

The AW f i r e extinguisher b o t t l e can be discharged f m the f l i g h t

compartment or from the main wheel weti.

PAGE 034
26.22.001
 m&E,Na IS7
MAINTENANCE TRAINING MANUAL

#->
,
i \\, APU GROUND
!, '\, CONTROL PANEL
\
,

\\\ V
'\

'\
\\

'. @
*,#,
---*

'\ ,/' EXTINGUISHER

-' BOTTLE

MODULE

APU F I R E EXTINGUISHING

001 PAGE 035

8 JAN 01/84 26.22.002
 7a7
BW!!EINe
MAINTENANCE TRAINING MANUAL

COMPONENT FUNCTIONAL DESCRIPTION

APU FIRE EXTINGUISHER BOTTLE

1. Purpose
The f i r e extinguisher b o t t l e contains the extinguishing agent f o r f i r e
suppression i n the APU shroud.

2. Location
The b o t t l e i s located i n the fuselage forward o f the APU compartment.
3. Physical Description
The spherical b o t t l e contains the extinguishing agent pressurized with
nitrogen t o 600 p s i a t ?O°F. Mounted on the b o t t l e are a pressure switch, a
fusible plug and a discharge p o r t w i t h cartridge. Yellow and red indicator
discs are located on the outside o f the fuselage i n the v i c i n i t y o f the
bottle.
6. Access
Access t o the b o t t l e i s through an access door on the l e f t side o f the
fuselage, forward o f the APU compartment.
5. Pouer
Power for the c a r t r i d g e operation i s 28 v o l t dc from the hot b a t t e r y bus.

6. Operation
The b o t t l e i s discharged by energizing the cartridge, which ruptures a disc;
the extinguishing agent flows from the b o t t l e t o the APU shroud. A t the same
time, the system discharge i n d i c a t o r (yellow disc) i s driven out and the hole
i s sealed by a piston.
Ifthe b o t t l e temperature increases t o approximately 266OF, the b o t t l e
discharges overboard, blowing out the red disc.
7. Haintenance Practices
Yhen the APU b o t t l e has been discharged the b o t t l e must be replaced. B o t t l e
replacement requi res disconnecting e l e c t r i c a l plugs and discharge tubing.

PAGE 036 002

26.22.003 FEB 22/86
 D!EINO7a7
MAINTENANCE TRAINING MANUAL

APU F I R E BOTTLE
ACCESS DOOR DISCHARGE
WRT \
DISCHARGE CARTRIDGE
ELEC TRICAL
CONNl ' '
4
A W F I R E EXTINGUISHER

k
4 I

ENGINE SHROUD PRESSURE SWITCH

ELECTRICAL CONNECTOR

DISCHARGE INDICATOR' R E L I E F PLUG

(YELLOY D I S C )
THERMAL RELIEF
INDICATOR
1 \
(RED DISC)

YELLOY

RING

BOTTLE DISCHARGE INDICATOR D I S C

d
PRESSURE R E L I E F INDICATOR D I S C
APU F I R E EXTINGUISHER BOTTLE

b 002
FEB 22/86
PAGE 037
26.22.004
 8'DE/#CP
MAINTENANCE TRAINING MANUAL

9PERAT ION

APU FIRE EXTINGUISHING SYSTEM

1. Nornal Sequence
Yhen f i r e has been detected, the APU f i r e handle i n the f l i g h t compartment
automatically unlocks. I t can also be unlocked by a manual override plunger
under the handle. P u l l i n g the f i r e handle closes the APU f u e l shut o f f
valve, a i r i n l e t door, and t r i p s the generator. Rotating the handle Left or
r i g h t allows 28 v o l t dc power t o the cartridge and the b o t t l e discharges.

Uhen b o t t l e pressure decreases t o 250 psi, a pressure switch closes and an

amber AW BOTTLE DISCHARGED l i g h t illuminates on P8 panel.
2. Backup Operation
P u l l i n g the f i r e handle on P28 panel i n the wheel well closes the APU f u e l
shut o f f valve, a i r i n l e t door, t r i p s the generator, and arms the b o t t l e
discharge switch, Using the discharge switch, 28 v o l t dc power i s supplied
t o the cartridge and the b o t t l e discharges. APU BOTTLE DISCHARGED l i g h t
illuminates on P8 panel. (The f i r e handle on P28 panel can be used t o stop
the APU i n emergency).
MAINTENANCE PRACTICES

Test

Using the extinguisher t e s t sui t c h on P8 panel checks the c o n t i n u i t y through

the cartridge.
Placing the switch t o p o s i t i o n 1 o r 2, allows power through the switch and
cartridge t o ground. I f ground i s present through the cartridge, the PUP
t r a n s i s t o r i s biased and the green APU b o t t l e test l i g h t illuminates.

PAGE 038 001

26.22.005 JAN 27/86
 1
m!!!H#& 7a7
MAINTENANCE TRAIHING MANUAL

2SV D t
HOT B I T . -
EXT BOTTLE
d
P6 P W E L

IRI BOTTLE
TEST LIGHT

HUlDLE RELEASE Y A M lllD

I
I W FIRE
CARTRIME
F I R E SU

METER C I R C U I T

llD&T PRESSURE SU
ARI
APU BOTTLE FIRE
D I S C H A M E SU 28V DC EXT
BOTTLE

PZB IPU 6ROlM CONTROL PANEL

1
P8 M G I N E I W D APU F I R E CONTROL PAMEL

i
!

Pzb I P u GRowD eonTRoL PANEL I

(RIGHT WHEEL YELL>

APU F I R E EXTINGUISHING S Y S T E M II
I

001
APR 25/86
PAGE 039
26.22.006 r L
I