Fire protection

Question 1

Which systems have fire detection?

Answer 1

Engines, APU, Lavatory, Cargo compartments, Wheel well

Question 2

Which systems have fire extinguishing systems?

Answer 2

Engines, APU, Lavatory, Cargo compartment

Question 3

Are the fire detection circuits for the main wheel wells AC or DC?

Answer 3

AC

Question 4

Except for the main wheel wells, the fire protection circuits are AC or DC?

Answer 4

DC

Question 5

What does an illuminated Master Fire Warning light indicate?

Answer 5

Fire in either the engine, APU, cargo compartment or Main gear wheel well

Question 6

How many fire detection loops are there per engine?

Answer 6

2

Question 7

How many fire detection loops are there in the APU?

Answer 7

1

Question 8

Why do the engines have dual loop detection?

Answer 8

Redundancy and to prevent false warnings - both loops must trigger to issue a fire warning

Question 9

How can single loop detection be selected for the engines in the event of a faulty loop?

Answer 9

The OVHT DET switch allows selection of a single loop

Question 10

What does the FAULT light on the fire detection panel indicate?

Answer 10

OVHT DET switch normal - both loops have failed
switch in A or B - selected loop has failed

Question 11

If the fault monitoring system detects a bad loop, what does it do?

Answer 11

Deselects the bad loop automatically

Question 12

If a loop is automatically deselected, what indication would be received in the flight deck?

Answer 12

No indication would be received

Question 13

Which 7 lights will illuminate if a fire is detected in engine 2?

Answer 13

2 - FIRE WARN lights
2 - MC
1 - Engine 2 OVERHEAT
1 - OVHT/DET
1 - Associated fire switch

Question 14

How many fire extinguishing bottles does the engine have?

Answer 14

2

Question 15

Are there limitations on which fire bottle can go into which engine?

Answer 15

No, either or both bottles can go into either engine

Question 16

What causes an engine fire switch to unlock?

Answer 16

A fire or overheat warning

Question 17

If the fire switch does not automatically unlock, how can it be unlocked?

Answer 17

Manual unlock button beneath the switch

Question 18

What actions does pulling the fire switch take?

Answer 18

HEEFAF

Hydraulics - closes hydraulic fluid SOV, low pressure light deactivated
Engines - thrust reverser deactivated
Electrical - trips generator control relay and breaker
Fuel - closes engine and spar fuel SOVs
Air - closes the bleed valve (lose associated wing a/i and pack)
Fire panel - Allows fire switch rotation for discharge, Arms one squib per bottle

Question 19

What happens when the fire switch is rotated?

Answer 19

Electrically fires one squib, discharging an extinguisher into the engine. Turning the handle the other way, fires the other bottle.

Bottle discharge light comes on after a few seconds.

Question 20

How many fire detection loops does the APU have?

Answer 20

1

Question 21

What does APU DET INOP light indicate?

Answer 21

Fault monitoring system has detected failure of the APU fire loop

Question 22

What indications will be received in the event of an APU fire inflight?

Answer 22

2x FIRE WARN
APU fire switch illuminated
Fire bell
Automatic shut down

Question 23

What additional indications will be received if an APU fire occurs on the ground?

Answer 23

Horn sound and light flashes in the wheel well

Question 24

What happens when the APU fire switch handle is pulled?

Answer 24

Fuel - deactivates fuel solenoid, closes fuel SOV
Air - closes APU bleed air valve
Electrical - trips generator control relay and breaker
Fire - allows handle to rotate for discharge, arms bottle squib

Question 25

How many fire detection loops are in the wheel well?

Answer 25

1

Question 26

What indications will be received if a fire in the wheel well is detected?

Answer 26

2x FIRE WARN
Wheel well red annunciator
Fire bell

Question 27

Describe the fire detection system for the cargo compartments?

Answer 27

Each forward and aft cargo compartment have their own dual loop detectors. Detection is based on smoke.

Question 28

What happens if a loop fails in the cargo compartment?

Answer 28

The other operative loop will trigger an alert

Question 29

What indications are received if a fire is detected in a cargo compartment?

Answer 29

FIRE WARN x 2
red FWD or AFT light
Fire Bell

Question 30

What does a DETECTOR FAULT light indicate?

Answer 30

both loops in one or both cargo compartments have failed

Question 31

Which annunciators on the FIRE PANEL will not result in a MC and OVHT/DET light?

Answer 31

Engine “FAULT” light and cargo “DETECTOR FAULT” light

Question 32

How long does the cargo compartment extinguishing bottle provide fire suppression?

Answer 32

75 minutes

Question 33

How long does it take to get a DISCH light after firing the cargo bottle?

Answer 33

up to 30 seconds

Question 34

What indications are received for smoke detection in the lavatory?

Answer 34

SMOKE light on overhead panel
Aural warning in lav
Red alarm indicator on lav smoke detector panel
Amber lav call light flashes

Question 35

How are the fire extinguishers in the lav activated?

Answer 35

Heat activated, melts a fuse which supplies fire suppression for 75 minutes

Question 36

What does the EXT TEST do?

Answer 36

Test for extinguisher continuity. Looking for 3 green lights

Question 37

What does the OVHT/FIRE test switch do?

Answer 37

Test the fire detection loops for engine, APU and wheel well
6 red lights, 5 amber + bell

Question 38

What does the FAULT/INOP test switch do?

Answer 38

Tests the fault detection circuits for both engines and APU
5 yellow lights

Question 39

What does the cargo fire test switch do?

Answer 39

Verifies extinguisher bottle squib circuit continuity