Ch.8 (Fire Protection)

Question 1

What happens when either illuminated Master FIRE WARN light is pushed?

Answer 1

• Extinguishes both FIRE WARN
• Silences the fire warning bell
• Resets the system for future warnings
• (On the ground) silences the Remote APU fire warning horn

Question 2

Which other switch provides the same function as pushing either Master Fire Warn light for an
engine fire warning?

Answer 2

Fire Warning Bell CUTOUT switch on the top center of the Overheat/Fire prot panel

Question 3

Which bus powers the Engine Overheat and Fire detection?

Which bus powers engine fire
extinguishing?

Answer 3

• Engine Overheat/ Fire detection: Battery Bus

- Engine Fire extinguishing: Hot Battery Bus

Question 4

What will cause an illuminated ENG OVERHEAT light and/or engine fire switch to extinguish?

Answer 4

Until the temperature drops enough to allow to gas in the fire loops retract enough to close the overheat and fire pressure switches

Question 5

With the OVHT DET switch in the A or B position, what initiates an overheat or fire warning?

Answer 5

The loops that the OVHT DET switch is positioned towards. The other loop is unmonitored

Question 6

With the OVHT DET switch selected to “A”, during an overheat/fire test, what does a FAULT light (amber) indication mean?

Answer 6

The selected loops have failed

Question 7

If one overhear/fire detector loop fails with the OVHT DET switch on NORMAL, how is a fire detected?

Answer 7

The remaining loop continues to detect overheats & fires

Question 8

What does rotating an engine fire switch do?

Answer 8

Electrically fires a squib, discharging the contents into the respective engine. Rotating the other direction fires the other bottle

Question 9

What causes a fire switch to unlock?

Answer 9

The illumination of the ENG fire switch or ENG overheat light unlock the fire switch

Question 10

Which bus powers the APU overheat and Fire detection?

Which bus powers the APU fire extinguishing?

Answer 10

• Overheat/Fire Det: Battery Bus

- APU Fire Extinguishing: Hot Batter Bus

Question 11

What does pressing the HORN CUTOUT switch on the APU Fire control panel (main wheel well) do?

Answer 11

Silences the fire warning bell, silences the APU fire warning horn, stops the APU fire warning light from flashing (maintains steady illumination)

Question 12

What power source is required for main wheel well fire detection?

Answer 12

2 AC Transfer Bus

Question 13

What components are tested with the Overheat/Fire Protection Panel test switch to OVHT/FIRE?

Answer 13

When held in this position, a test is initiated that checks Engine/APU overheat/Fire detection circuitry and related flight deck indicators. Includes overheat/fire detection loops on both engines, APU and main wheel well.

• Fire Bell
• FIRE warn lights
• Master Caution
• OVHT/DET annunciator
• ENG OVHT lights
• ENG fire switches illuminate
• APU fire switch illuminates
• Wheel well Fire warning light illuminates if AC power is avail

Question 14

What components are tested with the Overheat/Fire Protection Panel test switch to FAULT/INOP?

Answer 14

ENG/APU fault detection circuitry and Flight deck indicators.

• Master Caution Lights
• OVHT/DET system annunciator light
• FAULT light illuminates (If not the fault monitoring system is inop)
• APT DET INOP light

Question 15

What does a FAULT light (amber) illuminating during an OVHT FIRE test indicate?

Answer 15

A possible bad loop on an engine

Question 16

What does the ENGINES APU EXT/TEST switch test?

Answer 16

The squibs for the engine fire bottles and the APU fire bottle

Question 17

What does a DETECTOR FAULT light (amber) illuminated indicate when TEST is pushed and held on the Boeing Cargo Fire Panel?

Answer 17

One or more detectors in the related loop have failed

Question 18

When does the first bottle on the Boeing Lower Cargo Compartment Fire Suppression Dual Bottle System discharge? The second bottle?

Answer 18

• First Bottle: 1 press of the armed button and then 1 press of the discharge button
• Second Bottle: Automatically by times. Provides Halon for a total of 195 mins