01/18/23 Fire Protection

Question 1

What powers engine and APU overheat and fire detection?

Answer 1

Battery Bus

Question 2

What powers engine and APU overheat and fire extinguishing?

Answer 2

Hot Battery Bus

Question 3

How are Fire Detection Loop failures indicated?

Answer 3

The Fault light illuminates

Question 4

How is an engine or APU fire bottle discharged?

Answer 4

Rotating the switch

Question 5

Which system(s) are affected by pulling an Engine Fire Switch?

Answer 5

Closes,
- Engine Fuel Shutoff Valve and the Spar Fuel Shutoff Valve
- Engine Bleed Air Valve (loss of wing anti-ice)
- Hydraulic Fluid Shutoff Valve

• trips the Generator Control Relay
• disables thrust reverser
• arms one squib on each Bottle
• allows the Engine Fire Switch to be rotated

Question 6

What are the components of the APU Fire Detection and Extinguishing system?

Answer 6

• APU fire switch
• one APU Fire Extinguisher
• an APU BOTTLE DISCHARGED light

Question 7

What are the effects of pulling an APU Fire Switch up?

Answer 7

• provides backup for the automatic shutdown feature
• deactivates the fuel solenoid and closes the APU Fuel Shutoff Valve
• closes the APU Bleed Air Valve
• closes the APU Air Inlet Door
• trips the APU Generator Control Relay and Breaker
• allows the APU Fire Switch to be rotated for discharge
• arms the APU Fire Extinguisher Bottle squib

Question 8

Will the APU fire bottle discharge automatically for an APU fire?

Answer 8

No

Question 9

Where is the APU Fire Ground Control Panel?

Answer 9

Right Main Wheel Well

Question 10

Does the Main Wheel Well have a fire extinguishing system?

Answer 10

No

Question 11

How can the Fire Warning Bell be silenced?

Answer 11

Pushing either FIRE WARN light, Pressing the Fire Warning BELL CUTOUT switch, Pressing the APU HORN CUTOUT switch on the Ground Control Panel.

Question 12

What does placing the TEST switch on the Fire Protection Panel to FAULT/INOP and FIRE/OVHT test?

Answer 12

FAULT/INOP
position, a test is activated for the engine and APU module fault detection circuitry and related Flight Deck indicators.

OVHT/FIRE TEST
position, a test is activated for the engine and APU overheat and fire detection circuitry and related Flight Deck indicators. This includes the overheat and fire detection loops on both engines, the APU, and the main wheel well.

Question 13

How is a Lower Cargo Compartment fire detected?

Answer 13

At least one detector in each loop has detected smoke.

The Forward and Aft Lower Cargo Compartments each have smoke detectors in a dual loop
configuration. Normally, both detection loops must sense smoke to cause an alert.

Question 14

What does an illuminated DETECTOR FAULT (amber) light indicate on the Cargo Fire panel?

Answer 14

Indicates one or more detectors in the loops have failed.