Fire

Question 1

If an APU fire occurs will the APU automatically shut down and activate fire suppression?

Answer 1

No.

• APU shuts down, but fire suppression is not automatic. Fire suppression can be activated on the flight deck or the wheel well.

Question 2

Where is the APU FIRE checklist found?

Answer 2

QRC left side.

Question 3

What checklist is called for with the indications of a cargo fire?

What are those indications?

Answer 3

Indications:
- FIRE WARN
- FWD or AFT illuminated switch light
- FIRE BELL

Checklist:
- Lower Compartment CARGO FIRE on left side of QRC

Question 4

To extinguish a CARGO FIRE what is the process?

Answer 4

Press the illuminated FWD or AFT switch light, which then should illuminate ARMED. Then open the DISCH switch light and press. There may be a delay of up to 30 for the DISCH light to illuminate.

Question 5

What are the indications of a WHEEL WELL fire?

What is the checklist and where does it reside?

Answer 5

FIRE WARN

WHEEL WELL Light

Fire Bell

Checklist: WHEEL WELL FIRE checklist, QRC left side.

Question 6

An engine fire is reported to you while taxiing. What checklist is available and where is it located?

Answer 6

Engine Fire on Ground - QRH E.1

Question 7

Which areas of the aircraft have fire extinguishing capability?

Answer 7

• Engines • APU • Lower Cargo Compartments

Question 8

What fire protection functions are available without battery power?

Answer 8

Main wheel well fire detection is the only fire protection system not powered by the battery. Its power comes from AC Transfer Bus 2.

Question 9

Can you discharge the fire bottles using only battery power?

Answer 9

Yes into all areas Engines, APU and Lower Cargo Compartments with the battery switch in the OFF position because the extinguishing system is powered off the hot battery bus. Note fire detection requires that the battery switch be on because that is powered from the DC battery bus.

Question 10

How is the fire warning bell silenced?

Answer 10

Reset by either pushing the FIRE WARN lights or pushing the BELL CUTOUT switch on the Fire Protection panel.

Question 11

How is an engine fire extinguished?

Answer 11

Engine Fire Switches Engine fire extinguishing is accomplished with the engine fire switches. The engine fire switches are normally locked in the down detent to prevent an inadvertent shutdown of an engine. The illumination of an engine fire switch or ENG 1/2 OVERHEAT light unlocks the engine fire switch. The switch may also be unlocked manually using the override switch under the respective switch.

Question 12

Which systems are affected by pulling an engine fire switch and how are they affected?

Answer 12

For the Associated Engine:

• Closes engine fuel shutoff valve and spar fuel shutoff valve
• Trips generator control relay and breaker
• Closes hydraulic fluid shutoff valve (ENG HYD pump LOW PRESSURE light is inhibited)
• Closes engine bleed air valve and onside pack valve
• Disables thrust reverser
• Arms one discharge squib on each engine fire extinguisher bottle
• Allows the engine fire switch to be rotated for discharge

NOTE: The systems affected by pulling an engine fire switch are a lighter gray color on the forward overhead panel (Fuel, Electrical, Hydraulic, Air).

Question 13

How is a dual loop failure of an Engine Fire Detection System indicated?

Answer 13

A FAULT (amber) light will illuminate.

The FAULT light will also illuminate if the A or B loop is selected and the selected loop fails.

The OVHT/DET System Annunciator and MASTER CAUTION lights do not illuminate for a FAULT light.

Question 14

How many fire extinguishing bottles are provided for the APU?

Answer 14

A single halon bottle precharged with nitrogen.

Question 15

Does the APU have automatic fire extinguishing?

Answer 15

The APU automatically shuts down when an APU fire is detected but will not discharge the fire bottle.

Question 16

What happens when pulling the APU fire switch?

Answer 16

• Backups the auto feature
• closes the APU fuel shutoff valve
• closes the APU bleed air valve
• trips the APU generator control relay and breaker
• closes the APU air inlet door
• allows the APU fire switch to be rotated for discharge
• arms the APU fire extinguisher bottle squib.

Note does 7 things which matches total letters in APU FIRE

Question 17

Where is the APU Fire Ground Control panel located?

Answer 17

Right main wheel well.

Question 18

What does placing the fire detection TEST switch to FAULT/INOP test?

Answer 18

The FAULT/INOP selection tests the system’s ability to detect a fault or inoperative equipment and illuminate the lights associated with faults in the system.

The indications of a successful FAULT/INOP test are:

• both MASTER CAUTION lights illuminate
• OVHT/DET System Annunciator light illuminates
• FAULT light illuminates
• APU DET INOP light illuminates

The absence of any of these lights indicates a failed test.

Question 19

What does placing the fire detection TEST switch to OVHT/FIRE test?

Answer 19

Overheat and fire detection loops on both engines, the fire loop on the APU, and the fire detector in the wheel well.

This selection simulates an overheat or fire condition to test the system’s ability to detect an overheat or fire condition.

The indications of a successful OVHT/FIRE test are:
* fire warning bell sounds
* both master FIRE WARN lights illuminate
* both MASTER CAUTION lights illuminate
* OVHT/DET System Annunciator light illuminates
* both ENG OVERHEAT lights illuminate
* both engine fire switches illuminate
* both engine start switches illuminate
* the APU fire switch illuminates
* the WHEEL WELL light illuminates
* the wheel well APU fire warning horn sounds and the wheel well APU fire warning light flashes (if on the ground)

Question 20

What is indicated by the illumination of the DETECTOR FAULT light on the CARGO FIRE panel?

Answer 20

One or more detectors in the Lower Cargo Compartment Fire Detection System has failed.

Question 21

What fire protection and extinguishing equipment is available in the lower cargo compartments?

Answer 21

Two halon fire suppression bottles are installed
—a High-Rate Discharge (HRD) bottle and Low-Rate Discharge (LRD) bottle.

When the DISCH switch is pushed, the HRD bottle discharges into the selected compartment and a 15-minute timer begins. At the end of the 15 minutes, the LRD bottle is released into the selected compartment. This sequence provides 195 minutes of fire suppression: 180 minutes of flight plus 15 minutes of reserve. Discharge of the LRD bottle may be disabled by disarming the system. Upon landing, if the HRD bottle was discharged and the system remains armed, the LRD bottle discharge is inhibited.