08 Fire Protection

Question 1

a. Which aircraft areas have fire detection system

b. Which areas also have overheat detection systems?

Answer 1

a. APU, cargo compartments, engines, lavatories, main gear wells, overhead rest compartments.
b. The engines and main wheel wells.

Question 2

a. How many fire detection loops does each engine have?
b. How many detectors must sense a fire or overheat to produce an alert?
c. If a fault is detected in one loop, will a fire or overheat still be detected?
d. What does an EICAS message DET FIRE ENG (L or R) indicate?

Answer 2

a. There are multiple dual-channel detector assemblies in each engine nacelle.
b. At least one element on each channel must detect a fire or overheat condition.
c. Yes, the remaining channel element automatically switches to single channel operation.
d. Both main engine detector elements on a single assembly are faulted, no fire or overheat detection is provided.

Question 3

What are the indications of an engine fire?

Answer 3

• the fire bell sounds
• the master WARNING lights illuminate
• the EICAS warning message FIRE ENG (L or R) is displayed
• the engine fire switch LEFT or RIGHT fire warning light illuminates
• the engine fire switch unlocks
• the engine FUEL CONTROL (L or R) switch fire warning light I lluminates

Question 4

What are the indications of an engine overheat?

Answer 4

• the caution beeper sounds
• the master CAUTION lights illuminate
• the EICAS caution message OVERHEAT ENG (L or R) is displayed

Question 5

In flight, what conditions will unlock an Engine Fire Switch?

Answer 5

Automatically for a fire warning, or when the Fuel Control switch is in CUTOFF.
Manually by pushing the Engine Fire Override switch.

Question 6

What systems are affected if a fire switch is pulled?

Answer 6

• arms both engine fire extinguishers
• closes the associated engine and spar fuel valves
• closes the associated engine anti-ice valves
• trips the associated engine generators off
• shuts off hydraulic fluid to the associated engine–driven hydraulic pump
• depressurizes the associated engine–driven hydraulic pump
• removes power to the thrust reverser isolation valve

Question 7

What action is required to discharge an engine fire bottle following a fire?

Answer 7

Pull engine fire switch, then rotate to the required extinguisher position.

Question 8

a. How many engine fire extinguisher bottles are fitted?

b. What indications are given if the engine fire bottle is discharged or has low pressure?

Answer 8

a. Two, either or both bottles can be discharged into each engine.
b. The ENG BTL (1 or 2) DISCH light illuminates and the EICAS advisor message BTL (1 or 2) DISCH ENG shows.

Question 9

Where is the flight deck APU fire panel located?

Answer 9

On the overhead panel.

Question 10

Which systems are affected when the APU fire switch is pulled?

Answer 10

• arms the APU fire extinguisher bottle
• closes the APU fuel valve
• closes the APU air inlet door
• trips the APU generator field and generator breaker
• shuts down the APU (if automatic shutdown does not occur)

Question 11

Where is the APU ground control panel located?

Answer 11

Nose wheel well.

Question 12

How many fire extinguisher bottles does the APU have?

Answer 12

One.

Question 13

a. Will the APU shut down automatically for a fire

b. Will the fire bottle discharge automatically?

Answer 13

a. Yes.

b. Yes, after a 15 second delay to allow the fuel valve to close.

Question 14

Which areas are covered by the wheel well fire protection?

Answer 14

Main wheel well area.

Question 15

What does the main wheel well fire protection system consist of?

Answer 15

The main wheel well fire and overheat detection system consists of dual detector channels.

Question 16

What systems are affected when a CARGO FIRE ARM switch is selected to ARM?

Answer 16

• arms all cargo fire extinguisher bottles
• arms the selected compartment extinguisher valve
• turns off both lower recirculation fans
• shuts down cargo heat
• commands the packs to provide the minimum air flow required to provide pressurization
• shuts down the bulk cargo compartment ventilation system operation (aft cargo fire only)
• shuts down the lavatory/galley vent fan (aft cargo fire only)
• puts associated (fwd or aft) equipment cooling system in to the override mode
• turns off miscellaneous equipment cooling fan (forward cargo fire only)
• shuts off in-flight entertainment equipment (IFE) cooling
• turns off Nitrogen Generation System (NGS)
• shuts off door 4 galley chiller units (aft cargo fire only)
• out flow valves move to 50/50 flow split for air flow stability
• turns off zonal dryer fans

Question 17

What additional system is lost if smoke is detected in the aft cargo compartment?

Answer 17

HF radios.

Question 18

What are the indications of a cargo fire?

Answer 18

• the fire bell sounds
• the master WARNING lights illuminate
• the EICAS warning message FIRE CARGO (FWD or AFT) is displayed
• the CARGO FIRE (FWD or AFT) fire warning light illuminates

Question 19

How many cargo compartment fire extinguisher bottles are there?

Answer 19

Five

Question 20

How is a cargo fire extinguishing initiated?

Answer 20

Automatically on a fire warning from the cargo fire detection system, Or,
By pushing the associated CARGO FIRE ARM switch then push the CARGO FIRE DISCHARGE switch.


Question 21

How many bottles are discharged first and how is this indicated?

Answer 21

Two. CARGO FIRE DISCH switch light illuminates followed by the EICAS advisory BOTTLE DISCH CARGO.

Question 22

a. In-flight, when do the remaining bottles discharge?

b. Is this always the case?

Answer 22

a. After 15 minutes at a reduced flow rate.
b. No. If the airplane lands within the 15 minute time delay, only one of the remaining bottles discharges at the reduced rate on touchdown.

Question 23

What is the effect if a CARGO FIRE DISCHARGE switch is pushed whilst on the ground?

Answer 23

Three extinguisher bottles discharge simultaneously into the selected compartment, with the third bottle discharging at a reduced flow rate.