Cargo & Wheel Well Fire Ptotection

Question 1

The FWS & AFT cargo compartments are each equipped with ?

Answer 1

A single smoke detection unit

Question 2

What type of smoke detectors are fitted?

Answer 2

Photoelectric

Question 3

Both cargo compartments are protected from fires by how many cargo fire (extinguisher) bottles?

Answer 3

5 cargo fire bottles

Question 4

When discharged, what happens to the agent?

Answer 4

2 of the bottles empty immediately (Rapid dump bottles).

3 of the bottles meter the extinguishing agent into the compartment (Metered bottles).

Question 5

AFT CARGO FIRE ARM Switch does what?

Answer 5

1. Arms bottle squibs & flow valve squib
2. Shuts down various fans.
3. Commands packs to minimum flow
4. Shuts down AFT & BULK cargo heat systems.

Question 6

CARGO FORE DSCH Switch does what?

Answer 6

1. Rapid dump bottle discharge
2. Flow valve squib discharges
3. 20 min timer starts (used for discharging the metered bottles).

Question 7

Metered Bottle Discharge: The metered bottles discharge depending on the condition of the airplane & the timer. If the airplane has not landed after …….. mins, all ….. metered bottles discharge.

Answer 7

20 mins, 3 metered bottles

Question 8

What happens if the airplane lands before the 20 minute delay is complete?

Answer 8

1 of the metered bottles discharges upon touchdown.

Question 9

If the cargo fire occurs in flight, the landing altitude is set to a ………… altitude, this …………. the cabin altitude, which ………… cabin differential pressure, & …………… airflow around the cargo compartments.

Answer 9

Higher (altitude), increases, reduces, reduces

Question 10

FWD CARGO FIRE ARM Switch:

Answer 10

1. Arms bottle squibs & flow valve squib
2. Shuts down various fans
3. Commands packs to minimum flow
4. Equipment cooling override mode

Question 11

If both compartments are armed before discharge is initiated ?

Answer 11

The extinguishing agent is divided between the 2 compartments.

= an insufficient concentration in both compartments.

Question 12

What kind of fire detection system does the main hear have?

Answer 12

A dual loop fire detection system for each main gear is located in the main gear wheel well.

Question 13

Will high brake temperatures activate the Wheel Well Fire Detection System?

Answer 13

Not alone NO.

The system is designed to sense only the excessive temperature associated with a fire.

Question 14

The extinguishing system for the Wheel Well?

Answer 14

Nope, there isn’t one.

Question 15

How would you extinguish a wheel fire in the Wheel Well if there isn’t an extinguishing system?

Answer 15

Lower the landing gear to attempt to extinguish the fire & reduce temperature in the Wheel Well

Question 16

If you must retract the gear for airplane performance, leave the gear extended for at least …….. minutes after the wheel well fire warning has extinguished.

Answer 16

20 minutes

Question 17

Lavatory Fire Protection:

Answer 17

1. One (1) smoke detector in each lav
2. Aural alert & light
3. EICAS advisory msg
4. Heat activated fire extinguishing bottle

Question 18

What are the 3 conditions that cause a smoke detection unit to fail?

Answer 18

1. Faults in all 4 zones constitute a failure of the smoke detection system for that compartment.
2. If both channels of the detection unit fail.
3. If both fans fail.