B767 ATA 26 Student Book

TRAINING MANUALFOR TRAINING PURPOSES ONLY

B767-3S2F ATA 26-00 Page - -1 5/20/13 EFF - ALL

FIRE PROTECTION ATA 26


B767-3S2F ATA 26-00 Page - 0 5/20/13 EFF - ALL

THIS PAGE INTENTIANLLY LEFT BLANK



ATA 26 FIRE PROTECTION

TABLE OF CONTENTS......................................................................... 1

FIRE PROTECTION - INTRODUCTION ............................................... 2

FIRE PROTECTION - OPERATIONAL TEST ....................................... 4

FIRE DETECTION SYSTEM ................................................................. 6

ENGINE/FIRE OVERHEAT DETECTION TEST FIRE.......................... 8

ENGINE FIRE OVRHEAT DETECTION - INTRO ............................... 12

GENERAL DESCRIPTION.................................................................. 14

MAIN DECK CARGO SMOKE DETECTION SYSTEM - GEN DESC . 26

FREIGHTER LAV SMOKE DETECTION GENERAL DESC ............... 28

APU FIRE DETECTION - INTRODUCTION & LOCATION................. 36

GENERAL DESCRIPTION.................................................................. 38

APU FIRE DETECTION - INDICATIONS ............................................ 44

LWR CARGO COMP SMOKE DETECTION - INTRODUCTION......... 48

LWR CARGO COMP- SMOKE DET - FUNCTIONAL DESCRIPTION 56

AFOLTS CARD - FUNCTIONAL DESCRIPTION - DUAL LOOP ........ 62

WHEEL WELL FIRE DETECTION - INTRODUCTION ....................... 64

WING AND BODY DUCT LEAK DETECTION & INTRODUCTION .... 70

STRUT OVERHEAT DETECTORS - FUNCTIONAL DESCRIPTION . 76

ENGINE FIRE EXTINGUISHING - COMPONENT LOCATIONS ........ 80

APU FIRE EXTINGUISHING - INTRODUCTION ................................ 96

LOWER CARGO FIRE EXTINGUISHING - INTRODUCTION .......... 106



FIRE PROTECTION - INTRODUCTION

Purpose

The fire protection systems monitor the airplane for these conditions:

• Fire • Smoke • Engine overheat • Pneumatic duct leak • Strut leak detection

The fire protection systems also include fire extinguishers.

Fire/Overheat Detection

The airplane has these fire/overheat detection systems:

• Engine fire detection • Engine overheat detection • APU fire detection • Cargo compartment smoke detection • Wheel Well fire detection • Duct leak detection • Lavatory smoke detection • Electrical and electronic (E/E) cooling smoke detection

Extinguishing

• The airplane has these fire extinguishing systems: • Engine • APU • Cargo compartment • Lavatory • Portable fire extinguishers

Abbreviations and Acronyms

A/G - air ground systemAFOLTS - automatic fire overheat logic test system

APU - auxiliary power unitAPUC - auxiliary power unit controllerARINC - Aeronautical Radio, Inc.auto - automaticBIT - built-in-testBITE - built-in-test-equipmentbtl - bottlebtls - bottlescgo - cargoch - channeldisch - dischargeDLODS - duct leak and overheat detection systemECS - environmental control systemEDP - engine-driven pumpEEC - electronic engine controllerEICAS - engine indication and crew alerting systemENG - engineequip - equipmentext - extinguishingfwd - forwardind - indicatorkg - kilogramLED - light emitting diodeLRU - line replaceable unitMD&T - master dim and testMEC - main equipment centerovht - overheatovrd - overridepress - pressurePSEU - proximity switch electronics unitpwr - powerrmt - remotestby - standbyvlv - valveWEU - warning electronics unitWOW - weight-on-wheels



FIRE PROTECTION - INTRODUCTION

- FIRE/SMOKE - OVHT - FIRE

SYSTEMWHEEL WELL

- EXTINGUISHING

LAVATORY

- EXTINGUISHING

DUCT LEAKSYSTEM - FIRE

CARGO SYSTEMS

- EXTINGUISHING - FIREAPU SYSTEM

- EXTINGUISHING - OVHT - FIREENGINE SYSTEMS

PROTECTIONFIRE/OVHT



FIRE DETECTION SYSTEMEngine Fire

The left and right engine systems are identical. Each engine has a dual loop detector system. The engine fire loops are broken into three separate elements; the engine accessory area, the upper turbine area, and the lower turbine area. These detector loops send signals of a fire or fault condition to its interchangeable dedicated detector card. These detector cards are located in the P54 fire detection card file in the main equipment center. The detector cards discriminate between fire and fault conditions and send that message to the automatic fire/overheat logic/test system card (AFOLTS card) also located in the P54 file. If the programmed logic in AFOLTS is satisfied (AND logic when configured in dual loop), the AFOLTS card alerts the flight crew. Some of the flight compartment outputs are shown.

Engine Overheat

The overheat system is a very similar system to the engine fire system. The major differences are that only one segment is located on the engine, at the pneumatic ducting area, and that an overheat is a caution not a warning. AFOLTS card No. 1 is shared by left engine fire and left engine overheat, while the right engine uses AFOLTS card No. 2. All AFOLTS cards are interchangeable.

APU Fire

The APU dual detector loop system protects against APU compartment fires. There are two segments, one located above the APU on the air intake and one located below the APU on the clam shell door. The loops feed their detector cards (identical to the engine detector cards). The APU detector cards feed AFOLTS card No. 3. The flight compartment outputs are shown.

Wheel Well Fire and Duct Leak Detection

A single loop wheel well fire system is wired in series through both wheel wells into one detection segment. The Fenwal built system feeds the wheel well fire/duct leak detection card. This unique card is also in the P54 card file. Outputs from this card feed the wheel well fire indicators in the flight compartment. A wheel well fire is a warning alert. The three duct leak zones; left wing, right wing, and body, also feed the wheel well fire/duct leak detection card.

Cargo Smoke Detection System

The forward and aft cargo compartments contain two smoke detectors in each compartment. When a preset level of smoke is detected by both detectors(AND logic), the number six AFOLTS card outputs a cargo fire signal. The smoke detectors use a vacuum system to generate a blow through sample of compartment air for increased reliability.

Testing

The ENG/APU/CARGO test switch on the test panel sends an input to all AFOLTS cards to run a circuit check of the detector cards and a continuity check of the loops that feed them. If the cards and loops are working correctly, the AFOLTS cards will output fire and overheat signals to the flight compartment. If one loop fails, the test is still successful but the bad loop is annunciated on EICAS. If both loops fail, the test is unsuccessful and the test panel fail light illuminates. The wheel well test switch runs a continuity check of the wheel well detector loop. The duct leak continuity test is initiated at the P61 duct leak panel. If the duct leak lights illuminate, the system is continuous.



FIRE DETECTION SYSTEM



ENGINE FIRE OVERHEAT DETECTION - GENERAL DESCRIP-TION

General

Each engine has two fire detection loops. A fire detection card in the system card file monitors the loops for fires, overheat conditions, and faults. There is a fire detection card for each engine.

Overheat Detection

If the fire detection loops find an overheat condition, the fire detection card sends a signal to the AFOLTS card and to the warning electronics unit. The AFOLTS card sends a caution message and turns on the master caution light.

The warning electronics unit turns on the master caution light and overheat aural warning.

When the overheat condition goes away, the indications go away.

Fire Detection

If there is an engine fire, the detection loop sends a signal to the fire detection card. The detection card sends a signal to the AFOLTS card. The AFOLTS card sends signals to the warning electronics unit and to flight deck indications.

When the fire is out, the indications go away.

Continuous Fault Monitoring

The fire detection card monitors the two loops and the wiring for defects. In normal (dual loop) operation, both loops must have a fire or overheat to cause the flight deck indications.

If a failure occurs in a loop, the fire detection card sends the data to AFOLTS. A status message shows. The system changes to single loop operation with the FIRE/OVHT TEST switch on the P8 panel. In this mode, fire and overheat indications occur when one loop is defective and the other has a fire or overheat condition.

System Tests

Use the FIRE/OVERHEAT test switch on the P8 panel to do a test of the system. Test indications are the same as the actual fire and overheat warning indications.



ENGINE FIRE OVERHEAT DETECTION - GENERAL DESCRIPTION

FIRE LIGHT

FIRE

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG

ENGINE FIRE CONTROL PANEL

FIRE TEST PANEL

FAIL

ENG/APU

FIRE/OVHT TEST

CARGOWELLWHL SYS FAIL

P-RESET

CIRCUITSAND TESTINDICATIONSAND FAULTFIRE, OVHT

CARD 2AFOLTS

CARD LOOP 2R OVHT DET

P54 FIRE DET CARD FILE

CARD LOOP 1R OVHT DET

CARD LOOP 2R FIRE DET

CARD LOOP 1R FIRE DET

DET LOOP 2R NACELLE OVHT

DET LOOP 1R NACELLE OVHT

DET LOOP 2R ENGINE FIRE

DET LOOP 1R ENGINE FIRE

CARD 1AFOLTS

CARD LOOP 1L FIRE DET

CARD LOOP 2L FIRE DET

CARD LOOP 1L OVHT DET

CARD LOOP 2L OVHT DET

DET LOOP 1L ENGINE FIRE

DET LOOP 2L ENGINE FIRE

DET LOOP 1L NACELLE OVHT

DET LOOP 2L NACELLE OVHT



ENGINE FIRE OVERHEAT DETECTION - INTRODUCTION

Purpose

The engine fire/overheat detection system has these functions:

• Gives warnings in the flight compartment if there is a fire in an engine nacelle

• Gives caution indications in the flight compartment if an engine has an overheat condition

• Does tests on the system • Changes system operation in relation to pass/fail status of detector loops • Gives flight compartment messages for system condition



ENGINE FIRE OVERHEAT DETECTION - INTRODUCTION

DUAL LOOP ENGINE FIREAND OVERHEAT DETECTORS



FLIGHT DECK INDICATIONS - INTRODUCTIONS

Functional Description

A fire in the engine will display the following indications:

• Discrete warning display • Master warning light • Fuel control switch • Engine fire handle • Fire bell • EICAS warning message



FLIGHT DECK INDICATIONS - INTRODUCTIONS

LEFT

1 2DISCH

1 2DISCH

THG IR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG

FIRE CONTROL PANEL (P8)

P7

CAUTION

WARNING

(WARNING & CAUTION)

DISCRETE WARNINGDISPLAY (P1-3)

CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT

AURAL INDICATION SPEAKERS

L ENG FIRE LP 1L ENG FIRE LP 2

L ENG FIRE

FUEL CONTROL SWITCH MODULE (P10)

P7

CAUTION

WARNING

EICAS DISPLAY UNITS (P2)

FUEL CONTROL -RL-

CUT OFF

RUN



ENGINE FIRE DETECTION - FIRE DETECTORS

Purpose

The engine fire/overheat detection system monitors the engine for fire or overheat conditions.

Physical Description

The engine fire/overheat detection system has these components:

• Lower forward engine detector • Lower aft engine detector • Upper aft (firewall) detector • Forward upper overheat detector

Location

The lower forward detector is below the engine fan section. The lower aft detector is below the turbine section of the engine. The upper aft (firewall) detector is above the turbine section of the engine. The overheat detector is in the strut area of the engine.



ENGINE FIRE DETECTION - FIRE DETECTORS

ENGINE FIRE DETECTION SENSOR(TYPICAL)

ATTACHMENTSENSOR SUPPORT TUBEELEMENT LUG

UPPER AFT ENGINEFIREWALL FIRE DETECTOR

LOWER AFTENGINE FIRE

UPPER FWD ENGINEOVERHEAT DETECTOR

DETECTORLOWER FORWARDENGINE FIRE DETECTOR



ENGINE FIRE DETECTORS - FUNCTIONAL DESCRIPTION


Two sensing elements are parallel on either side of a contoured rigid support tube. These elements have an tube with thermistor material with two embedded electrical conductors. Both ends of the tube are electrical connectors attached to the conductors with one of the conductors grounded to the shell of the connector.


When the overheat sensor loop gets to the trip temperature, the thermistor material in the tubing decreases in resistance and sends an overheat signal to the fire detector card.

When the LOWER FORWARD, LOWER AFT, and UPPER AFT fire detection sensors get to the trip temperatures, the thermistor material has decreased its resistance to the trip point and sends a fire signal to the fire detector card.

The fire detector sensors and overheat sensors have a discrete trip temperature for localized hot spots. The sensors reset when the temperature cools sufficiently.

The environmental temperature is provided to help determine the operating temperature and a guide to the capability of resetting the sensor.



ENGINE FIRE DETECTORS - FUNCTIONAL DESCRIPTIONTOLERANCE ALLOWANCE IS 50F1

TEMPERATURETEMPERATURETRIP TEMPERATURES

LOCATION

ENVIRONMENTAL

LOWER AFT 750F 650F

TOTAL LENGTH

RESET

(AVERAGE) (MAXIMUM)

750F

1100F

ONE FOOT DISCRETE(MAXIMUM) (MINIMUM)

LOWER FORWARD

UPPER AFT 800F

1050F

1150F

400F

700F

250F

500F700F

UPPER FWD (OVERHEAT) 600F 950F 500F 485F

1

ENGINE FIRE DETECTION SENSOR(TYPICAL)

UPPER AFT ENGINEFIREWALL

LOWER AFTENGINE FIRE

UPPER FWD ENGINEOVERHEAT DETECTOR

DETECTORLOWER FORWARDENGINE FIREDETECTOR

FIRE DETECTOR



AFOLTS CARDS - FUNCTIONAL DESCRIPTION - DUAL LOOP

General

The automatic fire and overheat logic and test system (AFOLTS) cards give indications of fire or overheat conditions when the detector cards receive alarm or fault signals from the fire or overheat detection loops. Outputs from the AFOLTS card give indications and flight compartment messages. The cards can operate in dual loop mode (normal) or single loop mode. The dual loop mode shows here.

An AFOLTS card receives alarm and fault signals from four detector cards. The detector cards connect to two fire detection loops and to two overheat detection loops.

During dual loop mode operation, an alarm or fault signal is necessary from the two detector cards to make an alarm warning of a fire or overheat condition.

EICAS

A single loop output shows as a message on the status and maintenance pages. If the two loops have an output (alarm), the EICAS display changes to a warning, and the loop messages are disabled.

Test

When the card is in the dual loop mode, it monitors loop 1 and loop 2 detector cards. If the detector card finds a fault with one or two of its loops during a power-up self-test or a manual test from the P8 panel, a fault signal goes to the AFOLTS card and the AFOLTS sends status and maintenance messages to the flight deck to show which loop has a failure. If there is a failure of one loop, the AFOLTS card ignores that loop, and the system operates in the single loop mode with different logic. If the two loops have failures, a SYS FAIL light and FIRE/OVHT SYS advisory message shows in the flight compartment.

Detector, card, or related wiring failures cannot give a valid fault output at the moment of a failure. These defective loops can only be found during a system test.

Automatic 60 Minute Test

The AFOLTS card automatically gives a self test command to the detection zones when the detection loops, fire/overheat/smoke, in a zone are in disagreement for more than five seconds, or the zone is already in the single loop mode.

The AFOLTS card gives the self test command every 60 minutes if the initial condition does not change or stays in the single loop operation.



AFOLTS CARDS - FUNCTIONAL DESCRIPTION - DUAL LOOP

TAKEOFF<20 SEC AFTER

<400 FEETRADIO ALTM

NOT PUSHEDMASTER WARN

WARNING ELECTRONICS UNIT (P51)

1

LOOP MSG(S&M)

LOOP MSG(S&M)

R EICAS COMPUTER

FIRE/OVHT SYS

L EICAS COMPUTER

LOOP MSG(S&M)

LOOP MSG(S&M)

FIRE/OVHT SYS

AFOLTS (TYP) (P54)

NOTE STATUS LOOP MSGS ARE INHIBITEDMAINTENANCE LOOP

:DURING AN ALARM.MSGS ARE SHOWN DURING AN ALARM.

P54

P54

FAULTALARM

FAULT

FOUND BY A FAILED TESTCIRCUIT INOPERATIVE SIGNAL AS

EXTENSION ON TAKEOFFSTARTS BY NOSE STRUT

2. FIRE SW LOCK RELEASE (P8)3. FUEL CONT SW LIGHT (P8)

1. FIRE SW LIGHTS (P8)

1. FIRE DISCRETE ANN (P1-3)

ALARM 2

ALARM 1

EICAS LOOP 2

EICAS LOOP 1

ALARM

FAULT TEST

ALARM TEST

FAULT TESTALARM TEST

CARDDETECTORLOOP 2

FIRE/OVHT TEST PANEL (P8)SEQUENCERTEST

CARDDETECTORLOOP 1

TEST SWITCH ENG/APU/CARGO

SYS FAIL LIGHT

2 2

1

2

T

T

2. FIRE WARNING BELL

1. MASTER WARNING LIGHTS (P7)

ALARM OR FAULT + NOTHING FORMORE THAN 5 SEC = TEST EVERY60 MINUTES.

SOFTWAREALARM + ALARM = ALARMALARM + FAULT = ALARM

FAULT + ALARM = ALARMFAULT + FAULT = FAIL LIGHT



AFOLTS CARDS - FUNCTIONAL DESCRIPTION - SINGLE LOOP

GeneralThe automatic fire/overheat logic test system (AFOLTS) can operate in either a dual loop mode or a single loop mode. The single loop mode is shown here.

The AFOLTS card can deselect a faulty detection loop after that loop has failed a test. The test may be either a self-test started when power is applied to the battery bus (or when power is interrupted for more than two milliseconds) or a manual test from the P8 panel.

After an AFOLTS card deselects a faulty loop, the fire/overheat detection system only needs a single alarm or fault signal from the remaining good loop.

If a fire or overheat condition is detected in the single loop mode, flight deck warning and indications are the same as for the dual loop mode.



AFOLTS CARDS - FUNCTIONAL DESCRIPTION - SINGLE LOOP

FAULT FAULT -OR-FIRE

OVHTALARM ALARM

LOOP 2LOOP 1

MAINTENANCE

AFOLTSDESELECTED BY

MODESINGLE LOOP

AFOLTSDESELECTED BY

X

X

X

X

MESSAGES

STATUS AND

INDICATION

AFOLTS CONFIG

MESSAGE SHOWN ONFIRE/OVHT SYS ADVISORYSYS FAIL LIGHT AND

MESSAGES ARE SHOW.MAINTENANCE LOOP

ARE INHIBITED DURINGSTATUS LOOP MESSAGES

AFOLTS CARD - LOGIC TABLE FOR SINGLE LOOP CONFIGURATION

AN ALARM.

1 2

X

X

X 2

X 1

X 2

X 1

FLIGHT DECK.



ENGINE/FIRE OVERHEAT DETECTION - INDICATIONS

Fire Indication

If there is an engine fire, these are the indications in the flight compartment:

• Fire switch light • Fire switch lock releases • Fuel control switch light • EICAS warning message, L (R) ENGINE FIRE • Discrete fire warning light • Flight compartment fire bell • Master warning lights

Overheat Indication

If an engine has an overheat, these are the indications:

• Discrete overheat annunciator light • EICAS caution message, L (R) ENG OVHT • Caution aural • Master caution lights



ENGINE/FIRE OVERHEAT DETECTION - INDICATIONS

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG


P7

CAUTION

WARNING

(WARNING & CAUTION)


CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT

AURAL WARNING SPEAKERS

FUEL CONTROL SWITCH MODULE (P10)

P7

CAUTION

WARNING


FUEL CONTROL RL

CUT OFF

RUN

L ENG FIREL ENG OVHT

L ENG OVHT LP 1L ENG OVHT LP 2




ENGINE/FIRE OVERHEAT DETECTION - TEST FIRE

General

The fire test switch (ENG/APU/CARGO) does a test of these systems:

• Engine fire/overheat detection • APU fire detection • Cargo smoke detection

Only the engine fire detection test is shown here.

Fire Test Indications

When you push the ENG/APU/CARGO test switch, these indications come on:

• Fire switch • Fuel control switch • Discrete fire warning light • Master warning lights • Flight compartment fire bell • Flight deck warning, status, and maintenance messages

Test Initiation

The test is started with the FIRE/OVHT TEST - ENG/APU/CARGO switch on the P8 panel. The complete test takes four seconds. During this time, all the engine fire detector loops show as flight deck messages.

Fire Test Pass

When you release the switch, all test indications go away. The systems may have faults which do not prevent flight. An example is a single loop fault in the engine fire detection system. A status message shows this fault. Refer to the Dispatch Deviation Guide to see if this fault will limit flight operations.

Fire Test Fail

When you release the switch, any faulty loops show on the EICAS status and maintenance pages. If one loop of the left engine fire detection system fails, for

example, that loop is deselected and the system changes to a single loop configuration using the input from the remaining good loop. If both left engine fire detection loops fail, the SYS FAIL light on the P8 test module comes on and the EICAS advisory message, FIRE/OVHT SYS shows. Push the fail light to turn off the light and remove the EICAS advisory message.



ENGINE/FIRE OVERHEAT DETECTION - TEST FIRE

TAT + 12CREV

+10c

1N

EGT

825

54.2 21.3

D-TOTAI

HOT

528

109.7

826

L ENG FIRE

FIRE/OVHT SYS

ECS/MAINT


EICAS DISPLAY UNITS(P2)

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG

ENGINE FIRE CONTROL PANEL (P8)

FAIL

ENG/APU

FIRE/OVHT TEST

CARGOWELLWHL

SYS FAIL

P-RESET

LOOP 1 AND 2SIGNAL 1

ALARM WARNING

SHOWS WHILE TEST SWITCH IS PUSHED

LWR FWD ENG FIRE DETLWR AFT ENG FIRE DET

TESTMANUAL

(E8)COMPUTERSL(R) EICAS

SIGNALSALARM/FAULT

FAULT SIGNALDUAL LOOP

SYSTEM

SPEAKERWARNING

CENTER QUADRANT

ALARM WARN

AURAL

LOOP 2 DET SIGLOOP 1 DET SIG

FIRE DETENG FIREWALL

1FOR LOOP TEST, LIGHT GOES OUT WHEN SWITCH IS RELEASED IF THE LOOPTEST IS SUCCESSFUL

SIGNAL 2

FIRE DETECTIONCARD FILE (P54)

WARNING ELECTRONICSUNIT (P51)

FUEL CONTROL RL

CUT OFF

RUN

AFT CONTROLSTAND (P8)

P7

WARNING

CAUTION DISCRETE WARNINGDISPLAY (P1-3)

CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT

(P10)



ENGINE FIRE/OVERHEAT DETECTION - TEST OVERHEAT

General

The fire test switch (ENG/APU/CARGO) does a test of these systems:

• Engine fire/overheat detection • APU fire detection • Cargo smoke detection

Only the engine overheat detection test is shown here.

Overheat Test Indications

When you push the ENG/APU/CARGO test switch, these indications come on:

• Master caution lights • Caution aural tone • Flight deck caution, status, and maintenance messages

Test Initiation

The test is started with the FIRE/OVHT TEST - ENG/APU/CARGO switch on the P8 panel. The test takes four seconds. During this time, all the engine overheat detector loops show as flight deck messages.

Overheat Test Pass

When you release the switch, all test indications go away. The systems may have faults which do not prevent flight. An example is a single loop fault in the engine overheat detection system. A status message shows this fault. Refer to the Dispatch Deviation Guide to see if this fault will limit flight operations.

Overheat Test Fail

When you release the switch, any faulty loops show on the EICAS status and maintenance pages. If one loop of the left engine overheat detection system fails, for example, that loop is deselected and the system changes to a single loop configuration using the input from the remaining good loop. If both left engine overheat detection loops fail, the SYS FAIL light on the P8 test module

comes on and the EICAS advisory message, FIRE/OVHT SYS shows. Push the fail light to turn off the light and remove the EICAS advisory message.



ENGINE FIRE/OVERHEAT DETECTION - TEST OVERHEAT


ECS/MAINT

L ENG OVHT LP 1L ENG OVHT LP 21

(E8)

L (R) EICASCOMPUTERS

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG

ENGINE FIRE CONTROL PANEL (P8)FAIL

ENG/APU

FIRE/OVHT TEST

CARGOWELLWHL

SYS FAIL

P-RESET

AFT CONTROL

UPPER FWD ENGOVHT DET

LOOP 1 DETECTORLOOP 2 DETECTOR


WARNINGELECTRONICS

P7

SYSTEM MANUALTEST

ALARM SIGNAL

AURAL WARNSPEAKERS(CAUTION)

LOOP 1 & 2ALARM/FAULTSIGNALS

1 SHOWS WHILE TEST SWITCH IS PUSHED DURINGLOOP TEST, REMOVED WHEN SWITCH IS RELEASEDIF THE LOOP TEST IS SUCCESSFUL

STAND (P8)

DUAL LOOP FAULT SIGNAL

UNIT (P51)

WARNING

CAUTION

TAT + 12CREV

+10c

1N

EGT

825

54.2 21.3

D-TOTAI

HOT

528

109.7

826

L ENG FIRE

FIRE/OVHT SYS



ENGINE FIRE EXTINGUISHING - INTRODUCTION

Purpose

The engine fire extinguishing system extinguishes fires in the engine nacelles.

General Description

The two fire extinguishing bottles contain halon fire extinguishing agent pressurized with nitrogen. You use the engine fire switches in the flight deck to release the halon. Halon from each bottle can go to the left or right engine. EICAS messages, status messages, and indicator lights show when the bottle pressure is low.



ENGINE FIRE EXTINGUISHING - INTRODUCTION

TUBEDISTRIBUTION

COMPARTMENTFWD CARGO

21


ENG BTL1 DISCHENG BTL

LEF

1 2DISCH

T

1 2DISCH

THGIR

2 DISCH



ENGINE FIRE EXTINGUISHING - COMPONENT LOCATIONS

Purpose

The engine fire extinguishing system extinguishes fires in the engine nacelles.

General Description

The two fire extinguishing bottles contain halon fire extinguishing agent pressurized with nitrogen. You use the engine fire switches in the flight deck to release the halon. Halon from each bottle can go to the left or right engine. EICAS messages, status messages, and indicator lights show when the bottle pressure is low.

Flight Deck Component Locations

The engine fire panel is in the flight deck on the P8 aisle stand.

Forward Cargo Compartment Component locations

The two engine fire extinguishing bottles are behind the right sidewall lining of the cargo door. Open the cargo compartment lining to get access to the bottles.



ENGINE FIRE EXTINGUISHING - COMPONENT LOCATIONS

SIDEWALLCARGO

2

BAY FLOORFWD CARGO

1

ENGINE FIRE BOTTLES

TUBEDISTRIBUTION


21FIRE CONTROL PANEL (P8)

ENG BTL1 DISCHENG BTL

LEF

1 2DISCH

T

1 2DISCH

THGIR

2 DISCH



ENGINE FIRE EXTINGUISHING - BOTTLES

Purpose

The engine fire extinguishing bottles contain the fire extinguishing agent.

Location

The engine fire extinguishing bottles are outboard of the right sidewall lining of the forward cargo compartment in the right rear corner.


The two engine fire extinguishing bottles are identical. Each bottle has these components:

• Safety relief and fill port • Low pressure switch • Two discharge assemblies • Switch test push button • Four mounting lugs

The engine fire extinguishing bottles are interchangeable with the APU fire extinguishing bottle.


The bottles contain 19 pounds of halon fire extinguishing agent pressurized to 825 psi with nitrogen. If the pressure in the bottle becomes too high, the safety relief and fill port opens so the bottle does not explode.

The discharge assembly has an explosive squib. An electric current from the fire extinguishing circuit fires the squib. This releases the halon through the discharge port.

The pressure switch gives flight deck indications when bottle pressure decreases. The switch monitors the pressure in the bottle and is normally open. When the pressure decreases because of a leak or because of bottle discharge, the switch closes and causes the EICAS message.

Training Information Point

When you replace bottles, handle them carefully to prevent damage. Compare the weight of the new bottle with the weight on the identification plate. This prevents installation of a bottle which is not full.

The discharge ports of the bottle for the left and right engines are different sizes and are also color coded. This prevents crossed connections.

WARNING: BE CAREFUL WHEN YOU MOVE THE FIRE EXTINGUISHING BOTTLE. THE FIRE EXTINGUISHING BOTTLE IS HIGHLY PRESSURIZED AND HAS AN EXPLOSIVE CARTRIDGE AS A COMPONENT. ACCIDENTAL DISCHARGE OF THE FIRE EXTINGUISHING BOTTLE CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMEMT.

WARNING: DO NOT TOUCH THE SQUIB BEFORE YOU DO THE PROCEDURES FOR DEVICES THAT ARE SENSITIVE TO ELECTROSTATIC DISCHARGE. ELECTROSTATIC DISCHARGE CAN CAUSE THE FIRE BOTTLE TO RELEASE ITS CONTENTS SUDDENLY AND CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.

WARNING: PUT A PROTECTIVE COVER ON THE SQUIB. IF YOU DO NOT PUT A PROTECTIVE COVER ON THE SQUIB, THE FIRE EXTINGUISHING BOTTLE CAN RELEASE ITS CONTENTS SUDDENLY AND CAUSE INJURY TO PERSONS.



ENGINE FIRE EXTINGUISHING - BOTTLES

LUG (4)MOUNTING

SAFETY RELIEFLOW PRESSURE

L SQUIB

RIGHT ENGINE

LEFT ENGINE

GROUND WIRE R SQUIB

DISCHARGE PORT(1-1/4 INCH)

DISCHARGE PORTPORT (1 INCH)

SWITCH TESTPUSH BUTTON

SW (375 PSI) AND FILLER PORT(1925 PSI)

ENGINE FIRE BOTTLE(TYPICAL)



ENGINE FIRE EXTINGUISHING - BOTTLE/SQUIBS

Purpose

The squib releases the halon from the engine fire extinguishing bottle.

Location

The squib is in the discharge assembly at the bottom of the fire bottle. Each fire bottle has two squibs, one for each engine.


The squib is an electrically operated explosive device. The squib is adjacent to a bottle diaphragm that can break. The diaphragm normally seals the pressurized bottle.


The squib fires when you put the fire switch to the DISCH 1 or DISCH 2 position. The explosion opens the diaphragm. Nitrogen pressure in the bottle pushes the halon through the discharge port.


You use the SQUIB TEST PANEL (P61) to do a squib test. See the fire protection section for more information about the squib tests.

WARNING: MAKE SURE THERE IS NO VOLTAGE AT THE ELECTRICAL CONNECTOR. IF THERE IS A VOLTAGE AT THE ELECTRICAL CONNECTOR, THE SQUIB CAN ACCIDENTALLY FIRE AND CAUSE THE FIRE EXTINGUISHING BOTTLE TO RELEASE ITS CONTENTS. ACCIDENTAL DISCHARGE OF THE FIRE EXTINGUISHING BOTTLE CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.

WARNING: PUT A PROTECTIVE COVER ON THE SQUIB. IF YOU DO NOT PUT A PROTECTIVE COVER ON THE SQUIB, THE FIRE EXTINGUISHING BOTTLE CAN RELEASE ITS

CONTENTS SUDDENLY AND CAUSE INJURY TO PERSONS.

CAUTION: DO NOT PUT A SHUNT PLUG ON THE SQUIB. THE SHUNT PLUG CAN CAUSE DAMAGE TO THE SQUIB PINS.

The electrical connectors and the discharge assembly interface threads are different sizes and colors for the left and right engine squibs. This prevents an incorrect connection.



ENGINE FIRE EXTINGUISHING - BOTTLE/SQUIBS

GLAND NUT

DISCHARGEPORT

SQUIB

GROUND LUG

DIAPHRAGM

DISCHARGEASSEMBLY

BOTTLE (REF)

ELECTRICALCONNECTOR

LEFT SQUIB RIGHT SQUIBSQUIB ASSEMBLY

(TYPICAL)



ENGINE FIRE EXTINGUISHING - ENGINE FIRE PANEL

Purpose

The engine fire switches and engine fire bottle discharge lights are on the engine fire panel in easy reach of the flight crew.

Location

The engine fire panel is in the flight deck on the P8 aisle stand.


The engine fire panel has a fire switch for each engine and a discharge light for each fire bottle.

Quick release fasteners attach the panel to the aisle stand structure. Electrical connectors connect the panel to the airplane wiring.



ENGINE FIRE EXTINGUISHING - ENGINE FIRE PANEL

ENGINE FIRE PANEL

ENGINE BOTTLEDISCHARGE

QUICK RELEASEFASTENER (4)

ELECTRICAL

ENGINE

ENGINE FIREWARN LIGHT

ENGINE FIREOVERRIDE SW

CONNECTOR

FIRE SW

LIGHTS



ENGINE FIRE EXTINGUISHING - ENGINE FIRE SWITCH

Purpose

The engine fire switch does these four things:

• Gives an indication of an engine fire • Stops the engine • Isolates the engine from the airplane systems • Controls the engine fire extinguishing system


The engine fire switch includes these parts:

• Engine fire warning light • Solenoid • Engine fire override button • Push-pull switch contacts (internal) • Rotary switch contacts (internal) • Electrical connector


The solenoid locks the fire switch, so you cannot pull it accidently. If an engine has a fire, the fire warning light comes on, and the solenoid energizes to release the switch.

The fire override button lets you pull the fire switch when the solenoid is not energized.

When you pull the fire switch, the push-pull switch contacts operate electrical circuits that stop the engine and isolate it from the airplane systems.

When you pull the switch, you can turn it left or right to a mechanical stop at the discharge position. The rotary switch contacts close and operate the fire extinguishing system.

When you release the switch, a spring moves the switch a small distance from the discharge position to open the switch contacts.

You must put the switch back to the center position before you can push the switch in.


The left engine and right engine fire switches are interchangeable. When operating the fire switches in the discharge position, make sure that the fire bottle discharge light illuminates.



ENGINE FIRE EXTINGUISHING - ENGINE FIRE SWITCH

SWITCH RELEASEDSWITCH LOCKED

SOLENOIDENERGIZED

ENGINE FIREOVERRIDE BUTTONPUSHED

ENGINE FIRE

ELECTRICALCONNECTOR

SWITCH POSITIONS

CENTER

DISCHARGE 2DISCHARGE 1

SPRING RETURNSPRING RETURN

(SWITCH CLOSED)(SWITCH CLOSED)

(SWITCH OPEN)(SWITCH OPEN)

ENGINE FIRE SWITCH (P8)

WARNING LIGHT

LEFT

DISCH21

SWITCH PULLED

ENGINE FIREOVERRIDEBUTTON

PUSH-PULLCONTACTS (INTERNAL)

ROTARY CONTACTS(INTERNAL)

MANUALLYSWITCH RELEASED

ELECTRICALLY



ENGINE FIRE EXTINGUISHING - BOTTLE DISCHARGE

General

Each bottle has two discharge assemblies. The discharge assemblies connect the bottles to the discharge manifolds. One manifold goes to discharge nozzles in the left engine nacelle. The other manifold goes to discharge nozzles in the right engine nacelle.


Explosive squibs in the discharge assemblies connect to the engine fire handles in the flight deck. Squibs for the left engine connect to the left handle. Squibs for the right engine connect to the right handle. A squib for bottle 1 fires when you rotate the related fire handle to DISCH 1. A squib for bottle 2 fires when you rotate the related handle to DISCH 2. When a squib fires, the bottle releases the halon into the engine nacelle.

A pressure switch monitors the pressure in each bottle. The switch turns on the discharge indicator light when the bottle pressure decreases. The switch also causes advisory and status messages to show.

Training information Point

Rigid tubes, color coded yellow, connect both bottles to the left engine nacelle. Flexible braided hoses, with a strip of blue tape, connect both bottles to the right engine nacelle. This color code prevents incorrect connection.



ENGINE FIRE EXTINGUISHING - BOTTLE DISCHARGE

TUBEDISTRIBUTION

21

ENGINE FIRE BOTTLES

(1 EACH SIDE)NOZZLE ON ENGINE

NOZZLES

L ENGINE

R ENGINE

RIGHT ENGINE(LEFT SIMILAR)

ON STRUT


21

BAY FLOORFWD CARGOSIDEWALL

CARGO

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG




ENGINE FIRE EXTINGUISHING - ENGINE FIRE CIRCUIT SWITCH - OPERATION

General

The engine fire switch includes these components:

• Solenoid • Fire warning lights • Two sets of electrical contacts

One set of contacts controls engine functions. The other set of contacts controls the engine fire extinguishing system.

Solenoid and Warning Light Operation

The solenoid energizes if an engine has a fire. This releases the fire handle so you can pull it. The engine fire warning lights come on to show the correct handle to use.

The same condition normally occurs in both engine fire switches when you do a fire/overheat test.

You can override the solenoid with the engine fire override button.

Out Position

The operations that happen when you pull the fire handle are on the chart.



ENGINE FIRE EXTINGUISHING - ENGINE FIRE CIRCUIT SWITCH - OPERATION

CLOSES PRESSURE REGULATION AND SHUTOFF

FIRE SWITCH

SW UNLOCKSOLENOID

NORMAL

FIRE

FUNCTION WHEN PULLEDSYSTEM

CAUTION &

SHUTS OFF ENGINE FUEL CONDITIONING ACTUATOR

VALVE (PRSOV)

RESETS FIRE BELL AND SHOWS MESSAGE FOR ENGSHUTDOWN ON CAUTION ANNUNCIATOR

SWITCH IS PULLED AND THEN TURNEDDISCHARGES FIRE EXTINGUISH AGENT WHEN FIRE

FIRE SWITCH WHEN ENG FIRE IS DETECTEDUNLOCKS FIRE SWITCH SOLENOID AND TURNS ON

ENGINE T/R

FUEL CONDITIONCONTROL

PNEUMATICS

HYDRAULIC POWER

ENGINE FUELSHUTOFF VALVE

EXTINGUISHINGENGINE FIRE

FIRE DETECTION

GENERATOR

CLOSES REAR SPAR FUEL SHUTOFF VALVE

TRIPS ENG GENERATOR FIELD RELAY AND GCB

CLOSES ENG HYDRAULIC PUMP SUPPLY SHUTOFF VALVE

REMOVES POWER TO T/R ISOLATION VALVE

FIRE SWITCH(INTERNAL CONTACTS)

(TYPICAL)

R R R R

CONTROL

WARNING

FIRE HANDLE

FIRE HANDLE LIGHTS

LIGHTS



ENGINE FIRE EXTINGUISHING - CIRCUIT - FUNCTIONAL DESCRIPTION

Bottle Discharge

The engine fire switch sends power from the hot battery bus to the engine fire extinguishing bottle squibs. To discharge the bottle, pull out the handle and turn the handle clockwise or counterclockwise. The DISCH 1 position operates the squib for bottle 1. The DISCH 2 position operates the squib for bottle 2.

Discharge Indication

When pressure in the bottle decreases, the pressure switch closes and makes a ground for the discharge indicator light. The ground also causes EICAS to show advisory and status messages.


You can do a check of the pressure switch circuit on the ground. Push and hold the test button to close the switch. The bottle discharge light in the flight deck should come on. Bottle discharge advisory and status messages should show.



ENGINE FIRE EXTINGUISHING - CIRCUIT - FUNCTIONAL DESCRIPTION

AA

AA

ENGINE FIRE

BOTTLE 2

DISCH 2

P

L ENG SQUIB

PRESSURE

ENGINE FIRE

BOTTLE 1

DISCH 1

LEFT ENGINE FIRE SW

ENG BTL 1 DISCH

ENG BTL 2 DISCH

MD&T

MD&T

28V DCHOT BATBUS

FIRE EXT

FIRE EXT

L ENG BTL 1

L ENG BTL 2

TESTBUTTON

P6-1 MN PWR DIST

EICAS COMPUTER

EXTINGUISHING

EXTINGUISHING

SWITCH

P

L ENG SQUIB

PRESSURE

TESTBUTTON

SWITCH28V DCHOT BATBUS

ENG BTL 1

ENG BTL 2

ADVISORY MSG



APU FIRE DETECTION - INTRODUCTION & LOCATION

Purpose

The APU fire detection system warns the flight or ground crew if there is an APU fire. The APU stops automatically if there is a fire. The APU has a fire extinguishing bottle forward of the APU firewall. You can stop the APU and discharge the extinguishing bottle from the P8 panel in the flight deck and the P40 panel on the nose gear.

Nose Landing Gear Component Location

The P40 service and APU shutdown panel is on the nose landing gear. The panel has an APU fire warning horn and an APU fire warning light.



APU FIRE DETECTION - INTRODUCTION & LOCATION

FIRE DETECTOR

P40 PANEL

FWD

APU BTLDISCH

DISCH APU

APU FIRE CONTROLPANEL (P8)

BOTTLEDISCHARGED

APUSHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

APU FIREWARNING HORN

APU FIREWARNING LIGHT

RS

LS

P40 SERVICE AND APU SHUTDOWN PANEL



GENERAL DESCRIPTION

General

The APU fire detection system has these components:

• APU fire detectors • Fire detection card • AFOLTS card

When a detector card for an APU fire detection loop senses a fire, it sends a signal to the automatic fire/overheat logic test system (AFOLTS) card.

The AFOLTS card uses AND logic, for example, both detector loops 1 and 2 must sense a fire for alarm signals to be sent.

When there is an APU fire, the AFOLTS card gives these indications:

• Warning light • Fire bell • APU fire handle light in red and unlocks • EICAS warning message, APU FIRE • APU remote shutdown panel warning light • APU warning horn when airplane is on ground

Also, when there is an APU fire, the APU shuts down.

To do a test of the system, push the ENG APU/CARGO test switch on the P8 test panel. This test gives flight compartment indications for engine fire and overheat. APU shutdown is prevented during the test.

The APU fire detection system has continuous and power-up tests. These tests do not send flight compartment verification, but failed APU loops show on the status and maintenance pages of EICAS.

When any test finds both loops defective, the system FAIL light comes on and the EICAS advisory message FIRE/OVHT SYS shows.



APU FIRE DETECTION - GENERAL DESCRIPTION

DISCH

APU BTLDISCH

APU

2DET

BOTTLEDISCHARGED

APUSHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECK CALL

FLIGHT INPH

SERVICE INPH

EMER EXIT LT TEST

WHEELWELL LIGHTS

OFF

APU FIRE

FIRE BOTTLE ARMED

APU FIREWARNINGHORN

RS

LS

EICAS DISPLAY UNITS

DISCRETE WARNING DISPLAY

LOOP 1 AND LOOP 2ALARM/FAULT SIGNALS

ALARM WARNING SIGNAL 2


LOOP 1 DETECTOR

LOOP 2 DETECTOR

INHIBITED DURING TEST

APU FIRE

SHUTDOWN PANELP40 APU REMOTE

WARNING ELEC


UNIT (P51)

BELL/

AURAL &MASTERWARNINGMODULES

(P1-3)

AFOLTSCARD 3

(P2)

GND

STATUS/MAINT

FIRE/OVHT SYS (C)APU FIRE (A)

APU FIRE LP 1APU FIRE LP 2

ALARM WARNINGSIGNAL 1

1DET

(E8)COMPUTERSL (R) EICAS

APU SHUTDOWN

P7 (2)

CAUTION

WARNING AURALWARNING

1

CHIME

1

CONTROLPANEL (P8)

AFT CONTROLSTAND (P8)

APU TEST

CONFIG

OVSPD

A/PDISC

FIRE

CABINALT

PULL UP

SYS FAILWELLWHL

FIRE/OVHT TEST

ENG/APUCARGO

P-RESETFAIL



NOSE LANDING GEAR COMPONENT LOCATION

Nose Landing Gear Component Location

The P40 service and APU shutdown panel is on the nose landing gear. The panel has an APU fire warning horn and an APU fire warning light.



NOSE LANDING GEAR COMPONENT LOCATION

BOTTLEDISCHARGED

APUSHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

RS

LS

NOSE LANDING GEAR




APU SHUTDOWNBUTTON BOTTLE DISCHARGE

BUTTON

BOTTLE ARMED

BOTTLE DISCHARGELIGHT

LIGHT

APU BTLDISCH

DISCH APU




APU FIRE DETECTORS

Purpose

The APU fire detectors detect fire or high temperatures in the APU compartment. The alarm signal shuts down the APU.


There are two fire detector assemblies. Each detector assembly has a loop 1 detector and a loop 2 detector attached to a support tube. The upper and lower fire detectors connect to make loop 1 and loop 2.

The fire detector assemblies have two sensing elements attached to a stainless steel support tube. The sensing element is used to find a fire or a temperature that is too hot. It consists of an Inconel tube with two electrical conductors in a thermistor material. The thermistor material in the Inconel tube decreases resistance when the material is heated.

Location

The upper detector assembly is attached to the airframe and the APU inlet plenum. The lower detector assembly is attached to the left APU access door.



APU FIRE DETECTORS

APU FIRE DETECTOR ASSEMBLY(TYPICAL)

ATTACHMENT LUGELEMENT SUPPORT TUBE

LOWER FIRE

UPPER FIREDETECTOR ASSEMBLY

DETECTOR ASSEMBLY(LEFT APU ACCESS DOOR)

APU COMPARTMENT(SIDE VIEW)



FIRE DETECTORS - FUNCTIONAL DESCRIPTION


The fire detector assemblies have two sensing elements attached to a stainless steel support tube. The sensing element is used to find a fire or a temperature that is too hot. It consists of an Inconel tube with two electrical conductors in a thermistor material. The thermistor material in the Inconel tube decreases resistance when the material is heated.

At normal ambient temperatures the sensing element resistance is high. The resistance decreases quickly as the element temperature increases. When the resistance decreases to a set point, an alarm signal goes to the AFOLTS card. If an electrical short occurs, the resistance decreases faster than when the high temperature causes the resistance change. The electrical short causes the logic in the detector card to send a fault signal to the AFOLTS card.

When the temperature decreases, the resistance increases above the reset value and the alarm signal stops.



FIRE DETECTORS - FUNCTIONAL DESCRIPTION

CONNECTION LOOP 1

QUICK RELEASECLAMP

SUPPORT TUBE

ELECTRICAL

ELECTRICAL

CONNECTION LOOP 2

HEAT SENSITIVEELECTRICALLYCONDUCTIVE MATERIAL

CENTRAL CONDUCTORS

1/16 INCH

APU FIRE DETECTOR

OUTER STEEL

(AS TEMPERATURE RISES,CONDUCTIVITY INCREASES)

(INPUT TO DETECTOR CARD)TUBE (GROUNDED)



AFOLTS CARD - FUNCTIONAL DESCRIPTION - SINGLE LOOP & DUAL LOOP

General - Dual Loop

The automatic fire and overheat logic and test system (AFOLTS) cards shows fire conditions when the detector cards receive alarm or fault signals from the fire detection loops 1 and 2. Outputs from the AFOLTS card give indications and flight compartment messages. The cards can operate in the dual loop mode (normal) or in a single loop mode.

An AFOLTS card receives alarm and fault signals from two detector cards. The detector cards connect to fire detection loops 1 and 2.

During dual loop mode operation an alarm or fault signal is necessary from the two detector cards to make an alarm warning of a fire condition.

General - Single Loop

The automatic fire/overheat logic test system (AFOLTS) can operate in a dual loop mode or a single loop mode.

The AFOLTS card selects a faulty detection loop off, after that loop fails a test. The test can be a self-test started when power connects to the battery bus or for a power interruption of more than two milliseconds, or the test can be a manual test from the P8 panel.

After an AFOLTS card finds a faulty loop in the fire detection system, only a single alarm or fault signal is necessary from the remaining good loop.

If a fire condition is found in the single loop mode, flight compartment warning and indications are the same as for the dual loop mode.

Test

When the card is in the dual loop mode, the card monitors loop 1 and loop 2 detector cards. If the detector card finds a fault with one or two of its loops during a power-up self-test or a manual test from the P8 panel, a fault signal goes to the AFOLTS card. AFOLTS sends status and maintenance messages to the flight compartment to show which loop has a failure. After a fault is found on one loop, the system does not use that loop and operates in the single loop

mode with different logic. If the two loops have failures, a SYS FAIL light shows on the P8 panel, and a FIRE/OVHT SYS advisory message shows on the flight compartment display.

Detector, card, or related wiring failures do not always give a valid fault output at the time of a failure. You must use the system test to find these loop failures.

Flight Compartment Messages

If the two loops have an output (alarm), the flight compartment warning message shows, and the loop status messages do not show.

Automatic 60-Minute Test

The AFOLTS card gives a self-test command to the detection zones when the detection loops, fire/overheat/smoke, in a zone are in disagreement for more than five seconds, or the zone is already in the single loop mode.The AFOLTS card gives the self-test command again each 60 minutes if the initial condition does not change or stays in the single loop operation.



AFOLTS CARD - FUNCTIONAL DESCRIPTION - SINGLE LOOP & DUAL LOOP


<400 FEETRADIO ALTM


2 FIRE WARNING BELL

1 MASTER WARNING LIGHTS (P7)


AFOLTS (TYP) (P54)

1

2 FIRE SW LOCK RELEASE (P8)3 FUEL CONT SW LIGHT (P8)

1 FIRE SW LIGHTS (P8)P54

P54

SOFTWAREFAULTALARM

ALARM + ALARM = ALARMALARM + FAULT = ALARM

FAULT FAULT + ALARM = ALARM

FOUND BY A FAILED TESTCIRCUIT NOT IN OPERATION SIGNAL

EXTENSION ON TAKEOFFSTARTS BY NOSE STRUT

LOOP MSG (S/M)

LOOP MSG (S/M)

FAULT + FAULT = FAIL LIGHT

1 FIRE DISCRETE ANNUN (P1-3)

ALARM 2

ALARM 1R EICAS COMPUTER

L EICAS COMPUTER

EICAS LOOP 2

EICAS LOOP 1

ALARM



CARDDETECTORLOOP 2

FIRE/OVHT TEST PANEL (P8)

SEQUENCERTEST

CARDDETECTORLOOP 1

TEST SWITCH ENG/APU/CARGO

SYS FAIL LIGHT

FIRE/OVHT SYS

2 2

LOOP MSG (S/M)

LOOP MSG (S/M)

FIRE/OVHT SYS

NOTE: STATUS LOOP MSGS INHIBITED

MAINTENANCE LOOP MSGS SHOW

T

(ADVISORY)

(ADVISORY)

DURING AN ALARM

DURING AN ALARM

2

1

ALARM OR FAULT + NOTHING FORMORE THAN 5 SEC = TEST EACH60 MINUTES

T



APU FIRE DETECTION - INDICATIONS

Purpose

The nose gear panel lets the ground crew stop operation of and extinguish the fire in the APU from the ground. The flight compartment also has a panel to stop operation of the APU and release the contents of the fire extinguishing bottle.


The flight compartment panel has a fire warning light and a T-handle to release the contents of the extinguishing bottle. The panel has a bottle discharge light.

The P40 panel has an APU fire warning horn and an APU FIRE warning light.

The panel has an APU SHUTDOWN button. The panel also has a FIRE BOTTLE ARMED light, APU BOTTLE DISCHARGE button, and BOTTLE DISCHARGED light.



APU FIRE DETECTION - INDICATIONS

BOTTLEDISCHARGED

APUSHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

RS

LS

NOSE LANDING GEAR




APU SHUTDOWNBUTTON BOTTLE DISCHARGE

BUTTON

BOTTLE ARMED

BOTTLE DISCHARGELIGHT

LIGHT

APU BTLDISCH

DISCH APU




APU FIRE EXTINGUISHING - INTRODUCTION

Purpose

The APU fire extinguishing system extinguishes fires in the APU compartment.

General

If there is a fire, you can release the APU fire extinguisher bottle content manually from the P8 APU fire control panel or from the P40 APU remote control panel.

The APU fire extinguishing system has these components:

• APU fire extinguishing bottle • APU fire extinguishing bottle squib • Cargo fire/engine control module • APU fire switches • APU remote control panel (P40)

A bottle is forward of the APU fire wall on the lower right side. When you release the bottle content, a nozzle moves the extinguishing agent to the APU compartment.

The bottle releases its content by a squib. Control of the squib comes from the flight compartment or from the APU remote control panel on the nose landing gear. Flight compartment operation is with the APU fire handle on the P8 panel.

This handle locks down by a solenoid that releases for an APU fire. After you pull the fire handle, you can turn it in either direction to release the bottle contents. A bottle discharge light on the P8 panel and also on the P40 panel comes on when the bottle pressure decreases.

EICAS messages and indicator lights show when the bottle pressure is low.

Operation

The APU fire extinguishing bottle holds halon fire extinguishing agent pressurized with nitrogen. A discharge assembly connects the bottle to a discharge tube. The tube goes to a discharge nozzle in the APU compartment.

An explosive squib in the discharge assembly releases the halon from the bottle. The squib connects to the fire switches.

A pressure switch monitors the pressure in the bottle. After the bottle releases its content, the switch causes the discharge indicator lights to come on. The switch also causes EICAS advisory and status messages to show.



APU FIRE EXTINGUISHING - INTRODUCTION

APU BTLDISCH

DISCH APU

APU REMOTE CONTROLPANEL (P40)

(NOSE LANDING GEAR)

BOTTLEDISCHARGED

APU FIRESHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

RS

LS

APU

SERVICE

BOTTLEEXTINGUISHINGFIRE


ACCESS

2

1TEST

AFT

FWDTEST 2

TEST 12A21

CARGO

RL APUENGSQUIB TEST

TEST PANEL (P61)



APU FIRE EXTINGUISHING - GENERAL DESCRIPTION

General

The APU fire extinguishing system has these components:

• APU fire extinguishing bottle • APU fire extinguishing bottle squib • Cargo fire/engine control module • APU fire switches • APU remote control panel (P40).

A bottle is forward of the APU fire wall on the lower right side. When you release the bottle content, a nozzle moves the extinguishing agent to the APU compartment.

The bottle releases its content by a squib. Control of the squib comes from the flight compartment or from the APU remote control panel on the nose landing gear. Flight compartment operation is with the APU fire handle on the P8 panel.

This handle locks down by a solenoid that releases for an APU fire. After you pull the fire handle, you can turn it in either direction to release the bottle contents. A bottle discharge light on the P8 panel and also on the P40 panel comes on when the bottle pressure decreases.

EICAS messages and indicator lights show when the bottle pressure is low.

Operation

The APU fire extinguishing bottle holds halon fire extinguishing agent pressurized with nitrogen. A discharge assembly connects the bottle to a discharge tube. The tube goes to a discharge nozzle in the APU compartment.

An explosive squib in the discharge assembly releases the halon from the bottle. The squib connects to the fire switches.

A pressure switch monitors the pressure in the bottle. After the bottle releases its content, the switch causes the discharge indicator lights to come on. The switch also causes EICAS advisory and status messages to show.



APU FIRE EXTINGUISHING - GENERAL DESCRIPTION

APU BTLDISCH

DISCH APU

APU REMOTE CONTROLPANEL (P40)

BOTTLEDISCHARGED

APU FIRESHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

APU

SERVICE

BOTTLEEXTINGUISHINGFIRE


ACCESS



APU FIRE EXTINGUISHING - EXTINGUISHING BOTTLE

Purpose

The APU fire extinguishing bottle contains the Halon fire extinguishing agent.

Location

The fire extinguishing bottle is on the forward side of the APU fire wall, in the control bay.


The fire extinguishing bottle has these components:

• Safety relief and fill port • Pressure switch • Squib • Two discharge assemblies

The fire extinguishing bottle is interchangeable with the engine fire extinguishing bottles. Caps cover one squib and discharge port.


The bottle contains halon fire extinguishing agent pressurized with nitrogen. If the pressure in the bottle becomes too high, the safety relief port opens.

The discharge assembly has an explosive squib. An electric current from the fire extinguishing circuit fires the squib. This ruptures the frangible disk which releases the halon through the discharge port.

The pressure switch gives control panel indications when bottle pressure decreases. The switch monitors the pressure inside the bottle and is normally open. When the bottle pressure decreases because of a leak or bottle discharge, the switch closes and causes an EICAS message, APU BTL 1/2.


To do a test of the switch circuits, push the manual override button on the pressure switch housing.

The squib can be removed and replaced without damage to the rupture disc. There is no squib installed on the unused discharge port. The unused port is capped off.

WARNING: INSTALL THE PROTECTIVE COVER ON THE SQUIB WHEN THE AIRPLANE WIRING IS DISCONNECTED FROM THE SQUIB. INCORRECT PROCEDURES OR EQUIPMENT COULD FIRE THE SQUIB AND CAUSE INJURY.



APU FIRE EXTINGUISHING - EXTINGUISHING BOTTLEDISCHARGE ASSEMBLY

PRESSURE SWITCHFRONT VIEW

LOOKING OUTBOARD TO THE RIGHT SIDE

CAP

BUTTONOVERRIDEMANUAL

CONNECTORELECTRICAL

FWD

SQUIB

SCREEN

DISKFRANGIBLE



APU FIRE CONTROL PANEL

Purpose

The cargo/APU fire control panel permits flight deck control of the APU and cargo fire extinguishing systems.

Location

The cargo/APU fire control panel is in the flight deck on the P8 aisle stand panel.


The cargo/APU fire control panel has a fire switch for the APU and a discharge light for the APU fire bottle.

Quick release fasteners attach the module to the aisle stand structure. Electrical connectors connect the airplane wires to the panel.



BTL DISCH

ARMEDARMED

DISCH

DISCH

FWD

FWD AFT

AFT

ARM

CARGO FIRE

APU BTLDISCH

APU

APU FIRE CONTROL PANEL (P8)



APU FIRE EXTINGUISHING - APU FIRE CONTROL PANEL & SWITCHES

Purpose

The cargo/APU fire control panel permits flight deck control of the APU and cargo fire extinguishing systems.

Location

The cargo/APU fire control panel is in the flight deck on the P8 aisle stand panel.


The cargo/APU fire control panel has a fire switch for the APU and a discharge light for the APU fire bottle.

Quick release fasteners attach the module to the aisle stand structure. Electrical connectors connect the airplane wires to the panel.

Purpose

The APU fire switch gives an indication of an APU fire and controls the APU fire extinguishing system.

Location

The APU fire switch is on the APU/cargo fire control panel.


The APU fire switch includes these parts:

• APU fire warning light • Solenoid • APU fire override button • Push-pull switch contacts (internal not shown) • Rotary switch contacts (internal not shown)

The fire warning light uses four lamps.


The solenoid locks the fire switch so you cannot pull it accidently. If the APU has a fire, the fire warning light comes on and the solenoid energizes to release the switch.

When you pull the fire switch, the push-pull switch contacts isolate the APU from the airplane systems.

When the switch is out, you can turn it left or right to a mechanical stop at the discharge position. The rotary switch contacts close and operate the fire extinguishing system.

When you release the switch, a spring moves the switch a small distance from the discharge position to open the rotary switch contacts.

The fire override button lets you pull the fire switch when the solenoid is not energized.

You must put the switch back to the center position before you can push the switch in.


The engine and APU fire switches are not interchangeable. The fire warning light labels and the electrical connectors are different.

When operating the fire switches in the discharge position, make sure that the fire bottle discharge light illuminates.



APU FIRE EXTINGUISHING - APU FIRE CONTROL PANEL & SWITCHES

DISCH APUCENTER

SPRING RETURN(SWITCH OPEN)

DISCHARGE(SWITCH CLOSED)

SPRING RETURN(SWITCH OPEN)

DISCHARGE(SWITCH CLOSED)

APU/CARGO FIRE CONTROL PANEL (P8) SWITCH POSITIONS

SWITCH RELEASEDSWITCH LOCKED SWITCH PULLEDMANUALLY

SOLENOIDENERGIZED

APU FIREOVERRIDEBUTTONPUSHED

SWITCH RELEASEDELECTRICALLY

APU BTLDISCH

DISCH APUAPU FIRE WARNINGLIGHT



APU FIRE SWITCH - OPERATION

Warning Light and Solenoid Operation

The APU fire warning light comes on if there is an APU fire. The solenoid energizes and releases the fire switch so you can pull it.

This also occurs when you do a fire/overheat test.

Out Position

When you pull the fire switch, these functions occur:

• Generator field trips • APU fuel shutoff valve closes • APU shutoff valve closes • APU stops • EICAS messages which are not necessary do not show • Fire warnings at the P40 panel are canceled

Discharge Positions

The left or right DISCH position operates the APU fire extinguishing bottle squib.



APU FIRE SWITCH - OPERATION

SW UNLOCKSOLENOID

NORMAL

FIRE

FIRE SWITCH(INTERNAL CONTACTS)

R R R RFIRE HANDLE LIGHTS

CLOSES AIR SUPPLY APU VALVE

FUNCTION WHEN PULLEDSYSTEM

CAUTION AND

SHUTS DOWN APU WHEN FIRE HANDLE IS PULLED

RESETS FIRE BELL

SWITCH IS PULLED AND THEN TURNED LEFT OR RIGHTDISCHARGES FIRE EXTINGUISHING AGENT WHEN FIRE

SHUTS OFF APU FIRE HORN AIRPLANE ON GROUND

APU IGNITION AND

PNEUMATICS

ENGINE FUELSHUTOFF VALVE

EXTINGUISHINGENGINE FIRE

FIRE DETECTION

GENERATOR

CLOSES APU FUEL VALVE

TRIPS APU GENERATOR FIELD RELAY AND GCB

WARNING

APUAND REMOTE FIRE LIGHT AT NOSE GEAR

UNLOCKS FIRE SWITCH SOLENOID. TURNS ON FIRESWITCH WHEN APU FIRE DETECTED

STARTING

FIRE SWITCH(TYPICAL)

FIRE HANDLELIGHTS



FUNCTIONAL DESCRIPTION - CIRCUIT

General

Power for the APU fire handle on the P8 panel and the APU shutdown switch on the APU remote panel (P40) comes from the 28v dc hot battery. When you pull the fire handle or push the external shutdown switch, the APU fire extinguisher arms. The fire handle normally has a lock until there is a fire.

After you pull the fire handle or push the external shutdown switch, you turn the fire handle or push the APU bottle discharge switch on the P40 APU remote control panel to release the fire extinguisher content.

The APU access doors must be closed for the fire extinguisher to have the correct effect.

When the pressure in the bottle decreases, the pressure switch on the bottle closes and connects a ground to the APU bottle discharge lights.


To do a test of the bottle discharge light circuit, you push the test button on the pressure switch assembly. This button connects the circuit and causes the two bottle discharge lights (P40 and P8) to come on. The message APU BTL also shows on the EICAS display.



FUNCTIONAL DESCRIPTION - CIRCUIT

PULL TO STOP APU, TURNTO RELEASE BOTTLE CONTENT

APU

APU

BOTTLE

EICAS COMPUTER

APU REMOTE CONTROL

FIREBOTTLE

DISCHARGEDBOTTLE

APU/CARGO FIRE

APU FIRE SWITCH

TEST 1

28V DCHOT BATBUS

APU 1FIRE EXT

(CW)

(CCW)

APU FIRE SW PUSHED P40

K421 EXTERNAL

APU BTL

(APU SHUTDOWN)

ADVISORY MSG

2

P11 CB PANEL

28V DCBAT BUS

FIRE INDAPU REMOTE

SHUTDOWN (P37)

CONTROL PANEL (P8)

ARMED

FIRE EXT

P6 CB PANEL

PANEL (P40)

G

1

A

A

SQUIB

PRESS

P

SWITCH

<400 PSI

DISCHARGE

MD&T

APUBOTTLE

2

1

SQUIB TESTPANEL (P61)

APU BTLDISCH



FREIGHTER LAVATORY - SMOKE DETECTION SYSTEM GEN-ERAL DESCRIPTION

General

The smoke detection system uses the JAMCO smoke detector. This smoke detector uses the ionization type system. The alarm is self contained in the unit along with a test button and a horn silencing button.

System Tests

The smoke detector is tested on the unit.



FREIGHTER LAVATORY - SMOKE DETECTION SYSTEM GENERAL DESCRIPTION

SMOKE DETECTOR

ALARM HORN



LOWER CARGO COMPARTMENT SMOKE DETECTION - INTRODUCTION

Purpose

The system gives a FWD or AFT CARGO FIRE WARNING indication in the flight compartment when smoke is detected in the air of the forward or aft cargo compartments.



LOWER CARGO COMPARTMENT SMOKE DETECTION - INTRODUCTION

AFT CARGOCOMPARTMENT

FWD CARGOCOMPARTMENT

SMOKEDETECTORS (2)

SMOKEDETECTORS (2)



LOWER CARGO COMPARTMENT SMOKE DETECTION - GEN-ERAL DESCRIPTION

Purpose

There are different smoke detection systems for each cargo compartment. The smoke detectors are connected to a venturi ejector system to move air through the sampling tubes past the light diodes.

General

The detectors operate when the pneumatic system is powered to move air through the sampling tubes.

During AND logic (normal) operation, the two detectors must sense smoke to cause fire signals 1 and 2 to go to the AFOLTS card. During OR logic (one detector failure) operation, only one detector is necessary to send a signal to the AFOLTS card.

System Tests

AFOLTS card 6 monitors and does a test of the smoke detectors (fwd/aft). The annunciator lights and EICAS messages show this data:

• Location of a fire • Smoke detector with a failure • Detector fan with a failure • System (fwd/aft) with a failure.

You can use the ENG/APU/CARGO FIRE test switch to start a manual test. This test is almost the same as the power-up test.

General Component Locations

The smoke detector assemblies for the forward cargo compartment are located with the main deck smoke detector assemblies for zones A, B, and C. The smoke detectors are located on the left side of the lower forward cargo compartment across from the forward cargo door. The smoke detector assemblies for the aft cargo compartment are located with the main deck smoke detectors for zones D, E, and F. The smoke detectors are located on the left side of the aft lower cargo compartment across from the aft cargo door.

AFOLTS card No. 6 is in the fire detection card file (P54). The cargo fire detectors are tested from the FIRE/OVHT test panel (P8) using the same test switch for engine and APU fire loops.



LOWER CARGO COMPARTMENT SMOKE DETECTION - GENERAL DESCRIPTION

A2

1

DISCH

FWD

MAIN

AFT DISCHDEPR/

ARM

ARM

CARGO FIRE

DISCH

DEPR

FWD

ARMED

ARMED

AFT

ARMED

MAIN

WARNINGELECTRONICS UNIT (P51)

BELL/CHIMEAURAL&MASTERWARNINGMODULES

FWD CARGOCOMPARTMENT

COMPARTMENTAFT CARGO

SMOKE DET ASSEMBLY

AFOLTSCARD 6


FWD CARGODET 1

FWD CARGODET 2

SYSTEM MANUAL TEST

ALARM WARNING SIGNAL NO 2

ALARM WARNING SIGNAL NO 1

EICAS DISPLAYCOMPUTERSL(R) EICAS

FWD CARGO FIRE

FWD CARGO DET 1FWD CARGO DET 2

STATUS/MAINT

FIRE/OVHT SYS


LOOP 1 AND LOOP 2 ALARM/FAULT SIGNALS

CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT

WARNING

CAUTION

P7 (2)

FIRE BELL (2)

(E8)UNITS (P2)

FAIL

ENG/APUFIRE/OVHT TEST


P-RESET

FIRE/OVHT TEST PANEL (P8) CARGO FIRE CONTROL PANEL (P8)



FLIGHT DECK CONTROLS

Component Locations

These are the components in the flight deck that have an interface with the lower cargo compartment smoke detection system:

• Master warning and caution (P7) • FIRE/OVHT test panel (P8) • Fire bell (2) • Discrete warning display (P1-3)



FLIGHT DECK CONTROLSCARGO FIRE CONTROL PANEL (P8)FIRE TEST PANEL (P8)

FAIL

ENG/APU

FIRE/OVHT TEST


P-RESET

WARNING

CAUTION

P7 (2)

FIRE BELL (2)

A2

1

DISCH

FWD

MAIN

AFT DISCHDEPR/

ARM

ARM

CARGO FIRE

DISCH

DEPR

FWD

ARMED

ARMED

AFT

ARMED

MAIN



LOWER CARGO COMPARTMENT COMPONENT LOCATION

General Component Locations

The smoke detector assemblies for the forward cargo compartment are located with the main deck smoke detector assemblies for zones A, B, and C. The smoke detectors are located on the left side of the lower forward cargo compartment across from the forward cargo door. The smoke detector assemblies for the aft cargo compartment are located with the main deck smoke detectors for zones D, E, and F. The smoke detectors are located on the left side of the aft lower cargo compartment across from the aft cargo door.

AFOLTS card No. 6 is in the fire detection card file (P54). The cargo fire detectors are tested from the FIRE/OVHT test panel (P8) using the same test switch for engine and APU fire loops.



LOWER CARGO COMPARTMENT COMPONENT LOCATION

MAIN DECKSMOKE

FROMSAMPLINGPORTS

FROMSAMPLINGPORTS

SMOKESAMPLINGPORTS

SMOKE DETECTOR 2FWD CARGO

FWD CARGOSMOKE DETECTOR 1

TO VENTURIEJECTOR

TO VENTURIEJECTOR

AFT CARGOSMOKE

AFT CARGOSMOKE

AFT DETECTORS

FORWARD DETECTORS

DETECTOR DETECTOR 2

DETECTOR 1

MAIN DECKSMOKEDETECTOR



LOWER CARGO COMPARTMENT SMOKE DETECTION - SMOKE DETECTOR

Purpose

The smoke detectors monitor air in the cargo compartments for smoke. The venturi ejector provides the source of power to move the air from the cargo compartment into the smoke detector.


All cargo compartment smoke detectors are identical and interchangeable.

The detector consists of a photo diode and light emitting diode (LED) in a chamber. There are two printed wiring board assemblies in each chamber.

The detector has inlet and outlet tubes that protrude from the chamber to give airflow through the detector.


The smoke detector uses an optical principle to detect smoke. The detector consists of a photodiode and light emitting diode (LED) in a chamber. The detector has inlet and outlet tubes for air access. The beam of light from the light emitting diode shines into a light trap. The smoke particles reflect part of the beam of light onto the photodiode. The photodiode current increases with the amount of smoke that enters the detector. When the voltage is more than a preset level, a relay energizes to provide an alarm signal



LOWER CARGO COMPARTMENT SMOKE DETECTION - SMOKE DETECTOR

NON-REFLECTIVESURFACE

LEDPARTICLESSMOKE

PHOTO DIODE

INTENSITY

ALARMPHOTO

CONNECTOR

AIR IN

AIR OUT

SMOKE DETECTOR INTERNAL

DIODE

CONTROL

BEAMLIGHT

ELECTRICAL

FROMSAMPLINGPORTS

SMOKESAMPLINGPORTS



TO VENTURIEJECTOR

FORWARD DETECTORS




LOWER CARGO COMPARTMENT SMOKE DETECTION - DETECTOR LOCATION

Component Location

The forward cargo smoke detector assemblies are on the left side of the forward cargo compartment next to the main deck detectors zones A, B, and C. The smoke detectors are opposite the cargo door in the forward compartment. The aft cargo smoke detectors are on the left side of the aft cargo compartment next to the main deck detectors zones D, E, and F. The smoke detectors are opposite the cargo door in the aft compartment.

AFOLTS card 6 is in the P54 fire detection card file. The cargo fire detector tests are done from the FIRE/OVHT test panel (P8) with the same test switch for engine and APU fire loops.



LOWER CARGO COMPARTMENT SMOKE DETECTION - DETECTOR LOCATION

FROMSAMPLINGPORTS

SMOKESAMPLINGPORTS



TO VENTURIEJECTOR

FORWARD DETECTORS


SMOKEDETECTORS

JOINS VENTURI EJECTOR

SMOKE DETECTOR ASSEMBLY



LOWER CARGO COMPARTMENT SMOKE DETECTION - SMOKE DETECTOR - FUNCTIONAL DESCRIPTION


During normal operation, a beam of light from the light emitting diode shines into the light trap. Photo diode current comes from the light that reflects from the chamber surface.

As smoke enters the detector, a portion of the beam of light reflects from the smoke particles onto the photo diode. This causes the photo diode current to increase with the amount of smoke that enters the detector. Amplifiers raise this photo diode current to a detectable voltage level.

When the voltage is more than a preset level, a relay energizes to give an alarm signal.

A test of the smoke detector verifies that the LED light source is not burned out. The test also makes sure the smoke detector has a minimum guaranteed sensitivity.



LOWER CARGO COMPARTMENT SMOKE DETECTION - SMOKE DETECTOR - FUNCTIONAL DESCRIPTION

SMOKE DETECTOR

AIR IN

NON-REFLECTIVESURFACE

LEDPARTICLESSMOKE

PHOTO DIODE

INTENSITY

ALARMPHOTO

CONNECTOR

AIR IN

AIR OUT

SMOKE DETECTOR INTERNAL

DIODE

CONTROL

BEAMLIGHT

ELECTRICALELECTRICALCONNECTOR



INDICATIONS

Component Locations

These components in the flight compartment have an interface with the lower cargo compartment smoke detection system:

• Master warning and caution on P7 • FIRE/OVHT test panel on P8 • Discrete warning display on P1-3 • Fire bell (2)



INDICATIONS

ARMED

FWD

ARMED

AFT

ARMED

MAIN

SYS FAILWELLWHL

FIRE/OVHT TEST

ENG/APUCARGO

P-RESETFAIL

ENG/APUCARGO

FIRE/OVHT TEST PANEL (P8)CABIN

ALT

FIRE CONFIG

OVSPD

A/PDISCPULL UP

(P1-3)DISCRETE WARNING DISPLAY

DISCHDEPR/

CARGO FIREFWD

DEPR

MAIN

DISCH

A

AFT

RM

DISCHARM 1

CARGO FIRE CONTROL PANEL(P8)

P-5 PANEL

FIRE BELL (2)

WARNING

CAUTION

P7 (2)



AFOLTS CARD - FUNCTIONAL DESCRIPTION - DUAL LOOP

General

The automatic fire and overheat logic and test system (AFOLTS) card shows fire conditions when the detector cards receive an alarm from the smoke detectors. Outputs from the AFOLTS card give indications and flight compartment messages. The cards can operate in the dual loop mode (normal) or a single loop mode. The dual loop mode shows here.

An AFOLTS card receives alarm and fault signals from four smoke detectors, two in each of the cargo compartments. Each smoke detector is a loop.

During dual loop mode operation, an alarm or fault signal is necessary from the two detector cards to make an alarm warning of a fire condition.

EICAS

A single loop output shows as a message on the status and maintenance pages. If the two loops have an output (alarm), the EICAS display changes to a warning, and the loop messages do not show.

Test

When the AFOLTS card is in the dual loop mode, the card monitors loop 1 and loop 2 smoke detectors. If the AFOLTS card finds a fault with one or two smoke detectors for a cargo compartment during a power-up self-test or a manual test from the P8 panel, AFOLTS sends status and maintenance messages to the flight compartment to show which loop has a failure. If the card finds a fault with one loop, the system does not use that loop and operates in the single loop mode with different logic. If the two loops have failures, a SYS FAIL light and FIRE/OVHT SYS advisory message show in the flight compartment.

Smoke detectors or related wiring failures do not always give a valid fault output at the time of a failure. You must use a system test to find these loop failures.

Automatic 60-Minute Test

The AFOLTS card gives a self-test command to the detection zones when the detection loops, fire/overheat/smoke, in a zone are in disagreement for more than five seconds, or the zone is already in the single loop mode.

The AFOLTS card gives the self-test command again each 60 minutes if the initial condition does not change, or the system stays in the single loop operation.



AFOLTS CARD - FUNCTIONAL DESCRIPTION - DUAL LOOP

DETECTORSMOKESMOKE

LOOP 1DETECTORLOOP 2

ALARM OR FAULT + NOTHING FORMORE THAN 5 SEC = TEST EACH60 MINUTES

P54

P54

SOFTWAREFAULTALARM ALARM + ALARM = ALARM

ALARM + FAULT = ALARMFAULT FAULT + ALARM = ALARM 2 FIRE SW LOCK RELEASE (P8)

3 FUEL CONT SW LIGHT (P8)

1 FIRE SW LIGHTS (P8)

2 FIRE WARNING BELL

1 MASTER WARNING LIGHTS (P7)

FAULT + FAULT = FAIL LIGHT

1 FIRE DISCRETE ANN (P1-3)

ALARM 2

ALARM 1

EICAS LOOP 2

EICAS LOOP 1

ALARM

FAULT TEST

ALARM TEST


FIRE/OVHT TEST PANEL (P8)SEQUENCERTEST

AFOLTS (TYP) (P54)

TEST SWITCHENG/APU/CARGO

SYS FAIL LIGHT

2 2R EICAS COMPUTER

L EICAS COMPUTER

LOOP MSG (S&M)

LOOP MSG (S&M)

FIRE/OVHT SYS


<400 FEETRADIO ALTM



1

NOTE: STATUS LOOP MSGS INHIBIT DURING AN ALARM; MAINTENANCE LOOP MSGS SHOW DURING

FOUND BY A FAILED TESTCIRCUIT NO OPERATION SIGNAL ASEXTENSION ON TAKEOFFSTARTS BY NOSE STRUT1

2

AN ALARM

LOOP MSG (S&M)

LOOP MSG (S&M)

FIRE/OVHT SYS



MAIN DECK CARGO SMOKE DETECTION SYSTEM - GEN-ERAL DESCRIPTION

General

The smoke detection system for the main deck cargo compartment is divided into 6 zones (Zones A - F). The smoke detection system monitors the air in the cargo compartment and provides alerts for a smoke condition.

The main deck cargo compartment uses 12 smoke detectors arranged in 6 pairs making up two loops. Each main deck cargo compartment smoke detector connects to the test alarm interface module (TAIM). The TAIM transmits the status of loop one and loop two signals from the main deck smoke detectors in order to provide alarm signals to AFOLTS. The TAIM is located in the main equipment center by the E3 rack.

There is one AFOLTS card for main deck cargo compartment smoke detection. AFOLTS normally uses AND logic. If at least one smoke detector pair (loops 1 and 2) for the main deck sense smoke, you get the following indications:

• the red MAIN CARGO FIRE switch lights (on P8) • the red FIRE light (on P1-3) • the red master warning lights (on P7) • the fire bell sounds • MAIN CARGO FIRE warning message on EICAS

System Tests

The cargo smoke detectors are tested from the FIRE/OVHT test panel (on P8), using the same test switch for engine and APU. During a test, the TAIM sends the status of main deck cargo loops 1 and 2 to the AFOLTS card.



MAIN DECK CARGO SMOKE DETECTION SYSTEM - GENERAL DESCRIPTION

A2

1

DISCH

FWD

MAIN

AFT DISCHDEPR/

ARM

ARM

CARGO FIRE

DISCH

DEPR

FWD

ARMED

ARMED

AFT

ARMED

MAIN


CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT


(E8)COMPUTERSEICASL(R)

AFOLTSCARD 7

CARD FILE (P54)FIRE DETECTION

TEST/ALARMINTERFACEMODULE (M2039)

MAIN DECK LP 1SMOKE DETECTORS

SMOKE DETECTORSMAIN DECK LP 2

ELECTRONICSUNIT (P51)

WARNING

LOOP 1 AND LOOP 2


ALARM WARNING SIGNAL NO. 2

SYSTEM MANUAL TEST

&

BELL/CHIMEAURAL

MASTERWARNINGMODULES

MN CARGO FIRE

MN CARGO LP 1MN CARGO LP 2

SIGNAL NO. 1ALARM WARNING

WARNING

CAUTION

P7 (2)

AURAL

SPEAKER (WARNING)INDICATION

STATUS/MAINT

FIRE/OVHT SYS

ALARM/FAULT SIGNALS

FIRE TEST PANEL (P8)

FAIL

ENG/APU

FIRE/OVHT TEST


P-RESET



SMOKE DETECTION SYSTEM - VENTURI EJECTOR AND PRESSURE SWITCH

Venturi Ejector

The venturi ejector uses bleed air to create a vacuum condition to pull sample air through the smoke detectors in the main deck and forward and aft lower cargo compartments. Sample air in each of the zones is drawn through the detectors via a duct distribution system. Smoke entering the light-proof chamber of the smoke detectors reflects the light from the pilot lamp onto the photocell.

The photocell gives a signal to an amplifier where the signal is processed and sent to a relay which provides an alarm output signal to the fire/overheat logic test card. The ejector is located aft of the mix manifold in the forward cargo compartment.

Pressure Switch

The pressure switch is installed on the ejector plenum in the aft end of the forward cargo compartment. When the gauge pressure falls below approximately seven inches of water, the pressure switch closes and causes an EICAS message. When the pressure is eleven inches of water or greater, the pressure switch will open and the EICAS message will disappear.



SMOKE DETECTION SYSTEM - VENTURI EJECTOR AND PRESSURE SWITCH

EJECTOR

SWITCHPRESSURE

MIX MANIFOLD

EJECTOR AND PRESSURE SWITCH

FWD



MAIN DECK SMOKE DETECTORS

Purpose

The main deck cargo compartment uses 12 smoke detectors to check for smoke in order to give flight deck indications when there is a fire.

Component Location

Smoke detectors are near the cargo doors in the forward and aft cargo compartments.

The smoke detectors for the forward main deck (zones A, B, and C) are located opposite the FWD cargo door in the lower cargo compartment. The smoke detectors for the aft main deck (zones D, E, and F) are located opposite the AFT cargo door in the lower cargo compartment.

Air sampling tubes in the ceiling of each zone connect to the detector pair for that zone.


The smoke detector uses an optical principle to detect smoke. The detector consists of a photodiode and light emitting diode (LED) in a chamber. The detector has inlet and outlet tubes for air access. The beam of light from the LED shines into a light trap. The smoke particles reflect part of the beam of light onto the photodiode. The photodiode current increases with the amount of smoke that enters the detector. When the voltage is more than a preset level, a relay energizes to provide an alarm signal.



MAIN DECK SMOKE DETECTORS

SMOKELOWER LOBE

LOWER LOBESMOKE DETECTORS

FROMSAMPLINGPORTS

FROMSAMPLINGPORTS

FROMSAMPLINGPORTS

SMOKESAMPLINGPORTS

LOOP 2LOOP 1

LOOP 2LOOP 1

FORWARD DETECTORS

LOOP 2LOOP 1

LOOP 2

TO VENTURIEJECTOR

LOOP 2LOOP 1

LOOP 2

LOOP 1

AFT DETECTORS

TO VENTURIEJECTOR

LOOP 1

ZONEA

ZONE B

ZONE C

ZONE D

ZONE E

ZONE F

ZONEA

ZONEB

ZONEC

ZONE F

ZONE E

ZONED

DETECTORS

INTAKE ORIFICE

CEILING

CARGOCOMPARTMENT



MAIN DECK CARGO COMPARTMENT SMOKE DETECTION - FUNCTIONAL DESCRIPTION

Purpose

The test/alarm interface module (TAIM) consolidates the signal inputs from the six pairs of main deck smoke detectors. Two separate and identical sections support a dual loop configuration.

Component Location

The TAIM is in the main equipment center attached to the inboard side of the E-3 rack.


The module has twelve indicator lamps (LEDs), a lamp test switch and two loop test switches.


The main deck smoke detectors operate the same way as the smoke detectors for the lower cargo compartment. A single AFOLTS card serves the main deck smoke detectors. The AFOLTS card logic remains unchanged.

Signals to and from the 12 main deck smoke detectors go through the test/alarm interface module (TAIM) The TAIM has two separate and identical sections to support dual loop configurations. Each half of the TAIM unit is seen by the AFOLTS card as one smoke detector.

The TAIM consolidates the 12 inputs (6 per loop) from the main deck smoke detectors into two inputs (1 per loop). This allows the AFOLTS card to look at signals from any main deck smoke detector as being from loop 1 or loop 2.

During normal operation, the TAIM operates in OR logic. Any one of the six detectors that comprises main deck loop 1 or loop 2 may send an alarm signal to AFOLTS. For example, when loop 1 detects smoke in Zone A, the TAIM outputs a loop 1 alarm signal. Therefore, when loop 2 Zone C senses smoke, a second alarm signal also goes to AFOLTS.

A system test is conducted by pressing the ENG/APU/CARGO fire test switch, or from the TAIM front panel test switches. As far as the TAIM is concerned, there is no difference in the source of the test input. The TAIM operates in AND logic during a test. During a system test, all detectors must signal an alarm before the alarm will be transmitted to the AFOLTS card.

If a faulty smoke detector is found during test, the TAIM unit does not output an alarm signal to AFOLTS for that loop, and AFOLTS gives a status/maintenance message to EICAS MAIN CARGO LOOP 1 (2). If two loops are inoperative, the FIRE/OVHT SYS message shows.

Anytime a detector fails a test, that detector loop annunciation on EICAS and AFOLTS configures to single loop operation. Failed individual smoke detectors can be found by doing a test of the TAIM.



MAIN DECK CARGO COMPARTMENT SMOKE DETECTION - FUNCTIONAL DESCRIPTION

ABCDETDETDET

FDET

DDETDET

E

REGULATION

LED

PHOTODIODE

M2027 MAIN DECK SMOKE DETECTORLOOP 1 ZONE A

TESTOUTPUTREGULATOR

LIGHT

A

B

FDETDET

C BMANUALTEST

ALARMLOOP 2

TESTLOOP 2

TESTMANUAL

M2039 TEST ALARM INTERFACE MODULE

DETDETDETE D

BUSBAT.28V DC

28V DCR BUS

LT RESET

CARGO TEST

MAIN CARGO FIREDETECTION ALTNPWR-MAIN CARGO

MAIN CARGO FIREDETECTION-1

MAIN CARGO FIREDETECTION-2

ENG/APU

SYS FAIL

FIRE

P11 PANEL

FIRE/OVHT SYSTEM "C"

MAIN CARGO FIRE "A"

MN CARGO LP 1 "S & M"

MN CARGO LP 2 "S & M"

SYS FAIL LT

MN CARGO LP 1

MN CARGO LP 2

MAIN CARGO FIRE 2

M10445 FIRE/OVHTTEST PANEL (P8)

MD&T

M10445 FIRE/OVHTTEST PANEL (P8)

LOGIC TEST CARDM2026 FIRE/OVERHEAT

MAIN CARGO FIRE 1

SYS FAIL LT RESETSYS TESTDET 1 FIRE

DET 1 TEST

LOOP 1 ALARM

LOOP 1 TEST

28V DC DET 128V DC DET 2DET 2 FIRE

DET 2 TEST

MD&T

A HALF

MD&T

DISCRETE WARNINGDISPLAY (P1)

(L/R) EICAS COMPUTERS

LOOP 2*INSTRUCTIONS*

1C 1B 1A

2C 2B 2A

1F 1E 1D

2F 2E 2D

LOOP 1

PRESSTO

TEST

1. PRESS LAMP TEST VERIFY ALL INDICATORS

2. PRESS AND HOLD TEST SWITCH FOR LOOP UNDER TEST.

ILLUMINATE.

3. VERIFY SIX INDICATORS ILLUMINATE, IF DETECTORIS FAILED, INDICATOR WILL NOT ILLUMINATE.

4. RELEASE LOOP TEST SWITCH.

MAIN CARGO COMPARTMENTSMOKE DETECTOR TEST FOR

PRESSTO TEST

LAMPS

A B

FAILRESET

MAIN



LOWER CARGO FIRE EXTINGUISHING - INTRODUCTION

Purpose

The lower cargo fire extinguishing system extinguishes fires in the forward or aft lower cargo compartments.


The lower cargo fire extinguishing system has these components:

• Fire extinguishing dump bottle 1 • Fire extinguishing metered bottles 2 and 2A • Three manifold pressure switches • Two regulators • Two filter/dryers • Six non-metered discharge nozzles • Five metered discharge nozzles

The fire extinguishing bottles contain halon 1301 fire extinguishing agent pressurized with nitrogen. Tubes connect the bottles to discharge nozzles in the cargo compartment ceiling and sidewall.

Operation

In the flight compartment, cargo fire arm switches set the discharge to the forward or aft compartment. The discharge switch starts the fire bottle discharge sequence. A line pressure switch puts on the DISCH indication to show the start of the discharge sequence.

The dump bottle releases its contents into the selected compartment when you push the discharge switch. The bottle releases its contents quickly to extinguish the fire.

After a time delay, the metered bottles release their contents slowly and at a controlled rate through the filter, dryer, and regulator units. Halon from the metered bottles replaces the extinguishing agent in the cargo compartment to keep the fire extinguished for 180 minutes.

The fire extinguisher bottles operate differently in flight than on the ground. If the airplane is on the ground when you push the discharge switch, bottle 1

releases its contents immediately, and bottles 2 and 2A start a metered release that continues until the bottles are empty.

If you push the discharge switch in flight, bottle 1 releases its contents immediately, and bottles 2 and 2A start to release their contents 30 minutes after bottle 1.



LOWER CARGO FIRE EXTINGUISHING - INTRODUCTION

COMPARTMENT (REF)FORWARD CARGO

BOTTLES

ENGINE FIREEXTINGUISHER

BOTTLESFIRE EXTINGUISHERCOMPARTMENTCARGO

APU FIRE

BOTTLESEXTINGUISHER



LOWER CARGO COMPARTMENT - GENERAL DESCRIPTION

Flight Compartment

The flight compartment has a control panel to arm and operate the cargo fire extinguishing bottles to release the bottle contents into the forward or aft cargo compartment.

Lower Forward Cargo Compartment

The lower cargo fire extinguishing system uses these components to extinguish fires in one or the other lower cargo compartment:

• Fire extinguishing bottles (3) • Filter/dryers (2) • Manifold pressure switches • Regulators (2)



LOWER CARGO COMPARTMENT - GENERAL DESCRIPTION

NOZZLEOUTLETMETERED

AFT COMPT DOORCARGO

DOORCARGO

2A

TEMP COMPENSATEDLOW PRESSURE SWITCHES2

BULK

UNMETEREDOUTLET NOZZLE

(REF)DOORCARGO

LOW

CIRCUITINDICATION

CARGO COMPT SIDEWALLS

FILTER/DRYERMETERING NOZZLESMETERING NOZZLES

REGULATOR

FWD COMPT

SWITCHESPRESSUREMANIFOLD

TO DISCH

1

TO FWD COMPT

TO FWD COMPTTO AFT COMPT

UNMETERED NOZZLESTO AFT COMPT

UNMETERED NOZZLES

SWITCH

A2

1

DISCH

FWD

MAIN

AFT DISCHDEPR/

ARM

ARM

CARGO FIRE

DISCH

DEPR

FWD

ARMED

ARMED

AFT

ARMED

MAIN

80 LB

80 LB

BOTTLE 2A

BOTTLE 2

HALON

HALON33 LB

BOTTLE 2 MANIFOLD

SQUIB

PRESSURE SWITCHES

PRESSURE SWITCH

DISCHARGE

BOTTLE 1

BOTTLE 1 MANIFOLD

TUBING

HALONPRESSURE



LOWER CARGO FIRE EXTINGUISHING - EXTINGUISHING BOTTLES

Location

The bottles are on the right side of the forward lower cargo compartment behind the cargo compartment lining. You release the velcro and lift the lining up for access.


The bottles contain Halon 1301 fire extinguishing agent pressurized with nitrogen. Bottle 1 (dump) has 80 pounds of Halon. Bottle 2 (metered) has 92 pounds of Halon. Bottle 2A (metered) has 33 pounds of Halon. Each bottle has a nitrogen charge at a pressure of 360 psi.

The fire extinguishing bottles have these components:

• Safety relief and fill port • Pressure switch • Discharge assemblies

Indications

Status messages, maintenance messages, and the DISCH light on the P61 panel show if the bottle pressure is low.


The discharge assembly has an explosive squib that releases the Halon through the discharge port.

The pressure switch monitors the pressure in the bottle and is normally open. When the bottle pressure decreases, the switch closes and sends a signal.

The safety relief and fill port is one fitting on the bottle. The safety relief opens to make sure the bottle does not break if internal pressure is too high.

Filter/Dryer and Regulator Assemblies

A filter/dryer assembly and a regulator assembly are in the metering systems of the forward and aft cargo compartments. The filter/dryer cleans and dries the extinguishing agent. You must replace the filter/dryers after their use. The regulator controls the rate of discharge for bottle 2 and 2A.


You cannot fill an empty bottle on the airplane. You must replace the bottle. You can weigh the bottles to find the empty/full condition.

WARNING: BE CAREFUL WHEN DISCONNECTING THE HOSE ASSEMBLY FROM THE FIRE EXTINGUISHER BOTTLE. IF THE FIRE EXTINGUISHING BOTTLE IS DISCHARGED, THE TUBING MAY BE PRESSURIZED. RELEASING THE PRESSURE COULD CAUSE INJURY.

WARNING: DO NOT TOUCH THE SQUIB BEFORE DOING THE PROCEDURE FOR DEVICES THAT ARE SENSITIVE TO ELECTROSTATIC DISCHARGE. ELECTROSTATIC DISCHARGE CAN CAUSE THE FIRE BOTTLE TO RELEASE ITS CONTENTS SUDDENLY AND CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.

WARNING: BE CAREFUL WHEN YOU MOVE THE FIRE EXTINGUISHING BOTTLE. THE FIRE EXTINGUISHING BOTTLE IS HIGHLY PRESSURIZED AND HAS AN EXPLOSIVE CARTRIDGE AS A COMPONENT. ACCIDENTAL DISCHARGE OF THE FIRE EXTINGUISHING BOTTLE CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.



LOWER CARGO FIRE EXTINGUISHING - EXTINGUISHING BOTTLES

122A

DISCHARGESQUIB

DISCHARGEPORT

DISCHARGE

PRESSURESWITCH

PORT

RELIEFVALVE

THERMAL

DISCHARGESQUIB

PRESSURESWITCH

DISCHARGEPORT

THERMALRELIEF VALVE



LOWER CARGO FIRE EXTINGUISHING - EXTINGUISHING BOTTLES (CONT)

Tests

You must remove the fire extinguishing bottle each five years for a hydrostatic test. The date of the last test is on the bottle.

You can do a check of the low pressure switch on the ground. One person must push the button on the low pressure switch housing while a second person monitors the DISCH light on the P8 control stand and the EICAS advisory message. If the DISCH light comes on, the low pressure switch operates correctly. The light goes off when you release the button.



LOWER CARGO FIRE EXTINGUISHING - EXTINGUISHING BOTTLES (CONT)

122A

DISCHARGESQUIB

DISCHARGEPORT

DISCHARGE

PRESSURESWITCH

PORT

RELIEFVALVE

THERMAL

PRESSURESWITCH

DISCHARGEPORT

THERMALRELIEF VALVE



FUNCTIONAL DESCRIPTION BOTTLE DISCHARGE

Cargo Fire Switches

When the FWD ARMED switch is pressed, the following occurs:

• FWD cargo compartment heat valves close. • Fire warning bell is silenced. • FWD Squib test function is disabled. • FWD Cargo Air Conditioning shuts down

When the AFT ARMED switch is pressed, the following occurs:

• Aft and bulk cargo compartment heat valves close. • Fire warning bell is silenced. • AFT squib test function disabled. • The air conditioning packs switch to high flow mode.

Cargo Fire Switches

The cargo fire switch-lights have these functions:

• Compartment fire indication • Enables cargo fire bottle squib operation circuit and gives a circuit ARMED

indication

Bottle Discharge Switch

The bottle discharge switch has two functions, bottle discharge indication and squib operation of the cargo bottles.

When a fire shows in one of the cargo compartments (the red annunciator light in the cargo fire switch is on), you push the cargo fire switch to ARM the discharge circuit. You then push the discharge switch to operate the squib on bottle 1. If the airplane is on the ground, metered bottles 2 and 2A immediately release their contents. If the airplane is in the air, metered bottles 2 and 2A release their contents after 30 minutes.

A bottle discharge indication shows by a pressure switch on the bottle or a pressure switch in the discharge line. You must manually do a reset of the pressure switches in the discharge line after the extinguishing system operates.

To do a test of the pressure switch on the bottle and the discharge indication circuit, you operate the test switch on the bottle pressure switch.



FUNCTIONAL DESCRIPTION BOTTLE DISCHARGE

EICAS COMPUTER

METERED DISCHLINE PRESS SW

FWD CARGO

BTL 1

HOT BAT28V DC

CARGO

LWR CARGOAPU/CARGO FIRE CONTROL (P8)

CARGO BTL 2CARGO BTL 1

P6 MN PWR

DISCH

R MISC ELEC EQUIP PNL (P37)

MD&TINSTR LTS2

1

A A

ARMED

W W

FWD

RR

FWD CARGO

2

PSI

FWD CARGOSQUIB

>300

P

PSI

FWD CARGOSQUIB

>300

P

COMPT BTL 2

LWR CARGO

PSI

FWD CARGOSQUIB

>300

P

COMPT BTL 1

PSI25

PSI25

FEXT DISCHLINE PRESS SW

FWD CARGO

ADVISORY MSG

FEXT

BUS

DISTR

BTL 2

HOT BAT28V DC

CARGOFEXT

BUS

A

A

FWD CARGOCOMPT SMOKEDETECTION

1

FIRE SW

1

B

B

34

MUST PUSHPUSH TO TEST

TO RESET

BTL DISCH SWK2

K1

4 4

3

4

3

LWR CARGOCOMPT BTL 2A

NOTE: FWD CARGO COMPARTMENT SHOWN, AFT IS SIMILAR

FWD COMPT30 MIN

LOCK-IN RLY

TD

AIR

SYS NO. 2AIR GND RLY

GND

BTL 2ADISCH RLY



BOTTLE 2 AND 2A DISCHARGE CIRCUIT - FUNCTIONAL DESCRIPTION

Bottle Discharge Circuit for Bottles 2 and 2A

After you push the discharge switch, the squib on bottle 1 operates, and the fwd compartment lock-in relay energizes. Bottle 1 releases its contents immediately.

Bottles 2 and 2A start a metered discharge immediately if the airplane is on the ground. If the airplane is in the air, the metered discharge starts after a 30-minute delay.

A bottle discharge indication shows by a pressure switch on the bottle or a pressure switch in the discharge line.

You must manually do a reset of the pressure switches in the discharge line after the extinguishing system operates. To do a test of the bottle pressure switches and the discharge indication circuit, you push the test buttons on the bottle pressure switches.



BOTTLE 2 AND 2A DISCHARGE CIRCUIT - FUNCTIONAL DESCRIPTION

FWD GALLEY CHILLER, AND FWD/MID GALLEY PWR

MD&TINSTR LT

321

INPUTS TO PUT OFF RECIRC FANS, CARGO HEAT,

EICAS COMPUTER

METERED DISCHLINE PRESS SW

FWD CARGO

BTL 1

C781

HOT BAT28V DC

CARGO

LWR CARGOAPU/CARGO FIRE CONT (P8)

FWD COMPT

CARGO BTL 2CARGO BTL 1

P6 MN PWR30 MIN

DISCH

R MISC ELEC EQUIP PNL (P37)A A

ARMED

W W

FWD

RR

LOCK-IN RLYFWD CARGO

3

2

PSI

FWD CARGOSQUIB

>300

P

PSI

FWD CARGOSQUIB

>300

P

COMPT BTL 2

LWR CARGO

PSI

FWD CARGOSQUIB

>300

P

COMPT BTL 1

PSI25

PSI25

FEXT DISCHLINE PRESS SW

FWD CARGOAIR

ADVISORY MSG

FEXT

BUS

DISTR

BTL 2

C773

HOT BAT28V DC

CARGOFEXT

BUS

A

A

B

B

FWD CARGOCOMPT SMOKEDETECTION

1

FIRE SW

1

C

C

SYS 2

GND

BTL 2ADISCH RLY

BTL DISCH SWK2

K1

TD

LWR CARGOCOMPT BTL 2A

AIR GND RLY

NOTE: FWD CARGO COMPARTMENT SHOWS, AFT IS SIMILAR



FIRE PROTECTION - OPERATIONAL TEST

General

The operational tests for the fire extinguishing system are cargo squibs and engine and APU squibs.

You can do a squib continuity test of all bottles from the squib test panel. The squib test panel is on the P61 panel.

Cargo Squibs

The cargo squib test supplies current to the squibs on the cargo compartment fire extinguisher bottles.

Squib test switches on P61 give an easy test of all six squibs, two on each bottle. Power is from the 28v dc hot battery bus. This test makes sure there are no open circuits in the cargo compartment fire extinguishing squibs and the related wiring. Green lights show squib circuit continuity.

The squib operates with 3.5 amps. The test current is 50 ma.

The voltage drop across the test lamp does not let enough current flow to fire the squib. You must make sure the replacement lamps are the correct type and value. Accidental squib operation and bottle content release can occur.

Engine Squibs

The engine squib test supplies current to the squibs for the two engine fire extinguishing bottles.

You push these two switches on the P61 panel to do a test of the squibs:

TEST 1 - does a test of the two squibs on bottle 1TEST 2 - does a test of the two squibs on bottle 2

A successful test shows when the ENG L and R green lights come on.

APU Squib.

To do a test of the squib on the APU fire extinguishing bottle, you push the TEST 1 squib test switch on the P61 panel.



FIRE PROTECTION - OPERATIONAL TEST

DISCH

APU BTLDISCH

APU

BOTTLEDISCHARGED

APUSHUTDOWN

APU BOTTLEDISCHARGE

FLIGHT DECKCALL

FLIGHTINPH

SERVICEINPH

EMER EXITLT TEST

WHEELWELLLIGHTS

OFF

APU FIREFIRE BOTTLE

ARMED

APU FIREWARNINGHORN

RS

LS

REMOTE APUCONTROL PANEL

(P40)

LEFT

1 2DISCH

1 2DISCH

THGIR

R ENGOVHT2 DISCH

ENG BTL1 DISCH

ENG BTLOVHTL ENG

ENG FIRE

BOTTLE

APU/CARGO FIRE CONTROL PANEL

APU BOTTLE

ENG 2

CARGOBOTTLE

CARGOBOTTLE 2

ALL MESSAGES AREADVISORIES

EICASCARGOBOTTLE 1

2A

AIR

GND30-MINDELAY

ENG BTL 1 (C)ENG BTL 2 (C)

CARGO BTL 1 (C)CARGO BTL 2 (C)

APU BTL (C)CONTROL PANEL (P8)

BOTTLEENG 1

SQUIB TEST PANEL (P61)

2 2A1

AFT

FWDTEST 1

TEST 2

CARGO2

APU

SQUIB TEST

LENG

1RTEST

FWD

MAIN

AFT DISCHDEPR/

ARM

ARM

CARGO FIRE

DISCH

DEPR

FWD

ARMED

ARMED

AFT

ARMED

MAIN



WHEEL WELL FIRE DETECTION - INTRODUCTION

Purpose

The wheel well is protected from an overheat condition caused by hot landing gear brakes or tire fires.


Each element has a nickel wire around it and insulating material contained in the steel tube. The insulating material is heat sensitive and becomes more conductive when the temperature increases.

Location

The detector is a single loop detector on the ceiling of the wheel well bay.

Two sensors in series are attached to the top of each main wheel well.



WHEEL WELL FIRE DETECTION - INTRODUCTION

WELL FIRE DETECTORSSINGLE LOOP WHEEL



WHEEL WELL FIRE DETECTION - GENERAL DESCRIPTION

General

Two sensor loops are in the top of each main wheel well.

The wheel well fire detector is a single Loop Fenwal detection system. A signal from any wheel well fire detector element goes to the duct leak and wheel well fire card in the P54 fire protection card file.

The card causes flight compartment indications of a wheel well fire.

You do a test of the wheel well fire detection system from a test switch on the fire/overheat test panel on P8.



WHEEL WELL FIRE DETECTION - GENERAL DESCRIPTION

FAIL

ENG/APUFIRE/OVHT TEST


P-RESET

P7

CAUTION

WARNING


CABIN

PULL UP DISCA/P

OVSPD

CONFIGFIRE

ALT

FIRE/OVERHEAT TEST PANEL (P8)

WHEEL WELL FIRE (A)

FIREWHL WELL

TEMPBRAKE

&

BELL/CHIMEAURAL

MASTERWARNINGMODULES

ELECTRONICSUNIT (P51)

WARNING

DET LOOPWHEEL WELL FIRE

TEST

L(R) EICASCOMPUTERS

CARD FILE (P54)FIRE DETECTION

DUCTLEAK &WHEELWELLFIRECARD

EICAS DISPLAY UNIT (P2)

AURALWARNINGSPEAKER

(WARNING)

(E8)

EDGETRAILING

EDGELEADING

OFF

270KRETRACTUP

TEMP SEL

1 2CLBTOGA

CON CRZ

TAIL SKID

RAEG

NOSESROOD

LEFT RIGHT

P3-1



WHEEL WELL FIRE DETECTION - FUNCTIONAL DESCRIP-TION

General

When there is a fire and the temperature along a detector gets to 400F (204C), the resistance between the nickel wire and the grounded steel tube decreases.

The duct leak and wheel well fire card in the P54 card file senses this decrease.The card gives the flight compartment indications of a wheel well fire.

Operation of the wheel well test switch makes a ground for each detector loop and does a check of the continuity of the detection circuit. If the circuit has continuity, wheel well indications show.

A fault (short circuit) gives the same indications as a wheel well fire.



WHEEL WELL FIRE DETECTION - FUNCTIONAL DESCRIPTION

DUCT LEAK AND WHEEL WELLFIRE CONTROL CARD (P54)

DETCKT

FIREWHEEL WELL

L/R EICAS

UNITELECTRONICSWARNING

P3

P1

MD&T

MD&T

WHEEL WELL

(P37)FIRE IND

ELEM SENSORELEM SENSOR

ELEM SENSOR

RIGHT WHEELWELL DET

LEFT WHEELWELL DET

ELEM SENSOR

RIGHT WHEEL

LEFT WHEEL

WELL DET

WELL DET

WHEEL WELLTEST (P8)

P11

28V DCBAT BUS

WW FIREIND/TEST

P11

DUCT LEAKWW FIRE

STBY BUS115V AC

COMPUTER (E8)

FIREWHL WELL

FIRE


CENTRALCONDUCTOR

STEEL TUBEOUTER (GROUNDED)CONDUCTOR1/16 INCH

CONNECTOREACH END

DUCT LEAK DETECTION SENSOR(TYPICAL)



WING AND BODY DUCT LEAK DETECTION - INTRODUCTION

Purpose

The detector loop finds an increase in temperature around the pneumatic duct.


The duct leak detector is a Fenwal type detector with thermistor material in the tube. The detector has two conductors. The center conductor connects to the detector card, and the outer conductor (detector case) connects to airplane ground. The temperature sensitive thermistor material is between the two conductors. The wing duct leak detectors and body duct leak detectors are similar.

Location

The detector loop is parallel to the pneumatic ducts from the engine strut to wing joint to the left or right isolation valve and between the left and right isolation valves. The loop is also on the body pneumatic duct from the center isolation valve to the APU shutoff valve.



WING AND BODY DUCT LEAK DETECTION - INTRODUCTION

WING DUCT LEAKDETECTORS

WING DUCT LEAKDETECTORS

BODY DUCT LEAKDETECTORS



WING AND BODY DUCT LEAK DETECTION - DETECTORS

Purpose

Wing duct leak detectors monitor the pneumatic distribution ducts in the wing leading edges into the air conditioning compartments to the left and right isolation valves.

The body duct leak detectors extend from the center isolation valve to the APU fire wall.


The wing and body detection sensors (elements) are in a single loop circuit.Each element has a nickel wire and insulating material contained in a steel tube.

The insulating material is heat sensitive and becomes more conductive with a temperature increase.



WING AND BODY DUCT LEAK DETECTION - DETECTORS


CENTRALCONDUCTOR

1/16 INCH

CONNECTOREACH END

DUCT LEAK DETECTION SENSOR(TYPICAL)

OUTER CONDUCTOR(GROUNDED)

OUTER CONDUCTOR(GROUNDED)



WING AND BODY DUCT LEAK DETECTOR - FUNCTIONAL DESCRIPTION

General

When a segment of a duct leak detector gets to the overheat temperature, an alarm signal goes to the detection circuit on the duct leak overheat and wheel well fire card in the P54 card file. The detection circuit receives the signal and makes an alarm signal to put on the DUCT LEAK light on the P5 panel and the caution messages on EICAS in the flight compartment. When the duct leak detector decreases to the reset temperature, the alarm signal stops.


The duct leak test switch connects a ground for each detector loop and does a check of the continuity of the detection circuit. If the circuit has continuity, duct leak indications show.

A fault (short circuit to ground) gives the same indication as overheat condition.The test only operates on the ground.



WING AND BODY DUCT LEAK DETECTOR - FUNCTIONAL DESCRIPTION

BLEED AIR

DUCT LEAK AND

BODY DUCT LEAK

DUCT LEAK TEST

TEST PANEL (P61)(L WHEELWELL)

WING BLEED DUCT

WING BLEED DUCT

P11 PANELDUCT LEAKWW FIRE

L/R EICAS CMPTR

STBY BUS115V AC

R BLD DUCT LEAKL BLD DUCT LEAK

(L WING)(L WINGENG STRUT)

(AFTCARGO COMPT)

(ADP(FUSELAGETAIL)

GND

AIR

SYS 1 AIR/GND(P36)

(R WING) (R WINGENG STRUT)

CKTDET

DETECTORS - RIGHT

DETECTORS - LEFT

WHEEL WELL FIRE CARD(P54)

COMPT)

CKTDET

CKTDET

SUPPLY (P5)

MD&T

MD&T

MD&TOFF

DUCT LEAK

LEAKDUCT

LEAKDUCT

LEAKDUCT

40

60 80

20 0

DUCTPRESS

PSIRL

R ISLN

VALVE

C ISLN

UCT

D LEAK

F

OF

L ENG

L ISLN

VALVE

LEAKDUCT

BLEED

R ENGAPU

ADP

FFO

VA

EVL

OVHT

E

VALV

LEAKDUCT

BLEED

OVHT

DUCT LEAK



WING AND BODY DUCT LEAK DETECTION - STRUT OVER-HEAT DETECTORS

Purpose

The strut overheat thermal switches monitor the temperature in the engine strut. A leak in the pneumatic duct causes an overheat condition.


The strut overheat detectors are thermal switches that connect in a series configuration. The switch connects a ground when the temperature gets to a set level.

Location

There are two strut overheat thermal switches in each engine strut adjacent to the PRSOV.



WING AND BODY DUCT LEAK DETECTION - STRUT OVERHEAT DETECTORS

THERMALSWITCHMATERIAL



STRUT OVERHEAT DETECTORS - FUNCTIONAL DESCRIP-TION


When the temperature in the strut gets to a preset value, the strut thermal switch closes and gives an input to the bleed air control card. If the input signal is still there after a five-second time delay, the card latches and gives an output.

Output 1 shows the duct leak annunciator light on P5. Output 2 sends the EICAS message, L/R STRUT DUCT LEAK.

In the pneumatic system, the bleed air control card commands the high pressure shutoff valve and pressure regulating valve to close. This stops engine bleed air. If the pressure regulating valve or high pressure shutoff valve fails to close, the bleed annunciator light on the air supply panel comes on and the EICAS message of L/R ENG PRV or L/R ENG HPSOV shows.

To reset the system, cycle the engine bleed air supply switch.



STRUT OVERHEAT DETECTORS - FUNCTIONAL DESCRIPTION

LATCHRESET

BLEED AIRSUPPLY (P5)

MD&T

L WING ENGINE STRUT

L/R EICAS

R STRUT

L STRUT

ELECTRICAL SYSTEM CARD FILE (P50)

ON

AIR SPLY

OFF

L ENG BLDL BLEED AIR CONTROL PC

ALARM 2

ALARM 11

28V DCR BUS

P11 CB PANEL

R AIRSUPPLY ENG

ALARM 2

ALARM 11

FAILURE OF PRV OR HPSOV TO CLOSE SHOWS BY BLD LT AND RESPECTIVE ENG PRV FAIL OR ENG BLD VAL EICAS MESSAGESENDS CLOSE COMMAND TO HIGH PRESSURE SHUTOFF VLV AND PRESSURE REGULATING VLV. TO RESET, CYCLE BLEED SW1

DCT LEAK B

DCT LEAK B

CMPTR (E8)

BLEED CONT

28V DCR BUS

R AIRSUPPLY ENGBLEED CONT

SPLY PNL (P5)BLEED AIR

SPLY PNL (P5)BLEED AIR

R BLEED AIR CONTROL PC

RESET

LATCHRESET

PWR SPLY V

5 SEC

RESET

5 SEC

STRUT LEAK

FUEL QTYOFF

TEST PANEL (P61)

DUCT LEAKDET SNSR

K143 SYS 1AIR/GND (P36)

GND

R WING ENGINE STRUT

DUCT LEAKDET SNSR

DUCT LEAKDET SNSR

DUCT LEAKDET SNSR

MD&T

ON

AIR SPLY

OFF

R ENG BLD

PWR SPLY V

LEAKDUCT

LEAKDUCT



WING AND BODY DUCT LEAK DETECTION & INTRODUCTION

Purpose

The wing and body duct leak detection system monitors the pneumatic ducts from the APU to the center isolation valve and the engine ducts from the bleed valve to the left or right isolation valve for leaks.

The detection of a leak shows on the pneumatic panel and makes an EICAS CAUTION message.

Purpose

The detector loop finds an increase in temperature around the pneumatic duct.



40

60 80

20 0

DUCTPRESS

PSIRL

R ISLN

VALVE

C ISLN

UCT

D LEAK

F

OF

L ENG

L ISLN

VALVE

LEAKDUCT

BLEED

R ENGAPU

ADP

FFO

VA

EVL

OVHT

E

VALV

LEAKDUCT

BLEED

OVHT

FIRE PROTECTION

AIR SUPPLY PANEL (P5)

ELECTRICAL SYSTEMCARD FILE (P50)CARD FILE (P54)

BODY DETECTIONSENSOR LOOP

WING DETECTORSENSOR LOOPS

L BLD DUCT LEAKR BLD DUCT LEAKBODY DUCT LEAKL STRUT DCT LEAKR STRUT DCT LEAK

EICAS DISPLAY(CAUTION LEVEL B)

Documents

B767 ATA 26 Student Book