Fire Protection

Question 1

Which areas of the aircraft have Fire Detection systems?

Answer 1

Engines, APU, Main Wheel Well, Lower Cargo Compartment

Question 2

Which areas have fire Extinguishing/Suppression systems?

Answer 2

Engine, APU, Lower cargo compartment

SH 8.010 pg 14

Question 3

What does an illuminated Master FIRE WARN (red) light indicate? What causes it to
illuminate?

Answer 3

FIRE or TEST
Extinguished by pushing light or using BELL CUTOUT switch
SH 8.010 Pg 4 - check this info
SH 8.010 Pg 2

Question 4

What causes the Fire Warning Bell to sound?

Answer 4

Comes on in conjunction with the FIRE WARN light (test or actual fire detected)
SH 8.010 Pg 2

Question 5

How can it be silenced?

Answer 5

Pushing either FIRE WARN lights or the BELL CUTOUT.

SH 8.010 Pg 2

Question 6

What does an illuminated Engine Overheat (amber) light indicate?

Answer 6

an overheat condition

SH 8.010 pg 3

Question 7

What causes it to illuminate?

Extinguish?

Answer 7

The temperature of a detector has increased to a predetermined limit
SH 8.010 pg 4

Temperature drops below the predetermined limit - COOLS OFF
SH 8.010 pg 4

Question 8

How many engine fire extinguisher bottles are there?

Answer 8

2 total

SH 8.010 pg 4

Question 9

Can these bottles be discharged into both engines, or only the respective engine?

Answer 9

2 bottles total - 2 OR 1 discharges into one engine

SH 8.010 pg 5 schematic

Question 10

What powers the Engine Overheat and Fire Detection system?

Answer 10

Detection = BAT BUS

SH 8.010 pg 3

Question 11

What powers the Engine Fire Extinguishing system?

Answer 11

Extinguish = HOT battery bus

SH 8.010 pg 3

Question 12

What does pulling the engine fire switch do?

Answer 12

Lighter colors panels on overhead
Just think ISOLATE & VENTILATE and affects those panels
B - Bleed valve closes
R - Reverser disabled
G - Generator tripped
H - Hydraulic valve closes
F - Fuel valves close (engine fuel valve & spar valve)
S - Squibs & Switch (squib armed & switch able to be turned)
SH 8.010 pg 3

Question 13

What does rotating the engine fire switch do?

Answer 13

Electronically “fires” a squib, discharging the extinguishing agent into the
related engine. Rotating the switch the other way discharges the remaining
bottle.
SH 8.010 pg 6

Question 14

How many detector loops does each engine have?

Answer 14

2 loops

Question 15

What do the loops provide?

Answer 15

Fire and overheat detection

SH 8.010 pg 3

Question 16

What are the indications of a single loop failure?

Answer 16

No flight deck indication of a single loop failure

SH 8.010 pg 4

Question 17

What are the indications of a dual loop failure?

Answer 17

FAULT light (with OVHT DET switch in NORMAL)
SH 8.010 pg 4

Question 18

What does an illuminated FAULT (amber) light indicate?
What causes it to illuminate?
Extinguish?

Answer 18

Dual loop failure (with OVHT DET switch in NORMAL)
A or B loop failure (with switch in associated position)
SH 8.010 pg 4

The fault detection loops detects a fault
SH 8.010 pg 4

Doesn’t extinguish

Question 19

What does an illuminated Engine Fire (red) Switch indicate?

Answer 19

A fire (or a test)
*handle is unlocked when lit*

Question 20

What are indications of an engine fire?

Answer 20

Fire Warning Bell 
Both master FIRE WARN lights illuminate
Related engine fire switch illuminates
*related engine overheat alert indications likely illuminate 
SH 8.010 pg 4

Question 21

What are the components of the APU Fire Extinguishing system?

Answer 21

APU Fire switch
Single APU Fire bottle
APU bottle discharge light
SH 8.010 pg 9

Question 22

How many fire extinguisher bottles does the APU fire extinguishing system have?

Answer 22

ONE

SH 8.010 pg 9

Question 23

What does pulling the APU Fire (red) switch up do?

Answer 23

GBFISH
G - generator tripped
B - bleed valve closed 
F - fuel deactivated
I - inlet door closed
S - squib armed
H - handle unlocked
*auto shutdown should have occurred, but this will happen anyways if you pull the 
handle up*
SH 8.010 pg 9

Question 24

Rotating the switch APU Fire (red)?

Answer 24

Fires the APU squib into the APU

Question 25

Where is the APU Fire Protection Panel located, and what does it do?

Answer 25

RIGHT main wheel well. Same stuff as in the flight deck.

SH 8.010 pg 9

Question 26

What powers the APU Fire Detection system?

Answer 26

Battery Bus

SH 8.010 pg 8

Question 27

The APU Fire Extinguishing system?

Answer 27

Hot battery bus

SH 8.010 pg 8

Question 28

What are the components of the Main Wheel Well Fire Protection system?

Answer 28

Fire detection (only) and a single fire loop in the wheel well
SH 8.010 pg 13

Question 29

What does an illuminated WHEEL WELL (red) light indicate?

Answer 29

Indicates temp has exceeded predetermined limit

Cargo guy cooking weenies
SH 8.010 pg 13

Question 30

What causes the WHEEL WELL (red) light to illuminate?

Answer 30

Temperature sensed above predetermined limit

SH 8.010 pg 13

Question 31

What causes the WHEEL WELL (red) light to Extinguish?

Answer 31

Temperature decreases below onset temp

SH 8.010 pg 13

Question 32

What are the components of the Lower Cargo Fire Protection system?

Answer 32

Smoke detectors (10)
2 fire extinguisher bottles
- First bottle discharges for 60 min
- Second bottle discharges for 135 additional min to maintain the level of 
halon in the compartment
SH 8.010 pg 18

Question 33

What does an illuminated DETECTOR FAULT (amber) light indicate?

Answer 33

FAULT in one or more of the detectors

SH 8.010 pg 19

Question 34

An illuminated Cargo Fire FWD/AFT (red) light?

Answer 34

At least One detector in each loop has detected smoke (they agree)
SH 8.010 pg 16

Question 35

The FAULT/INOP and OVHT/FIRE TEST switch, when in the FAULT/INOP position, tests
what?

Answer 35

That the system is able to detect faults in itself

Question 36

What is being tested when fire test switch is in the OVHT/FIRE position?

Answer 36

Testing the fire detection circuitry

SH 8.010 pg 14 or use B737 app and test switches