Fire Protection

Question 1

How is engine fire detection provided?

Answer 1

A fire wire sensor cable routed the fire and overheat detection zones of each engine.

Question 2

If you get an Amber ‘LOOP FAIL’ synoptic on the overhead fire panel what is a likely cause?

Answer 2

A short circuit in the fire loop.

Question 3

When the engine fire control unit receives a fire/overheat signal from the fire loop, what cockpit warnings are generated?

Answer 3

1. ENG FIRE PUSH button illuminates.
2. Fire Bell
3. LH/RH ENG FIRE light on the RWP illuminates.
4. Red Master Warning lights illuminate/flash.

Question 4

Each engine has how many fire protection bottles?

Answer 4

2

Question 5

What cockpit indication would you have of a low pressure fire bottle due to a pilot-activated or thermal discharge?

Answer 5

A white ‘DIS’ light on the overhead fire panel.

Question 6

When are the fire bottle squibs armed?

Answer 6

When the ENG FIRE PUSH buttons are pressed.

Question 7

Pressing the ENG FIRE PUSH button does what?

Answer 7

1. Bleed Air shutoff valve closes
2. Fuel shutoff valve closes
3. Motive Flow valve closes.
4. Ignition (auto) is inhibited.
5. Generator relays open (AC and DC)
6. Squibs are armed (indicated by green SQUIB lights)

Question 8

How is APU fire detection provided?

Answer 8

A fire wire sensor cable.

Question 9

When the APU fire detection control unit receives a fire/overheat signal, what cockpit warnings are generated?

Answer 9

1. APU FIRE PUSH button illuminates
2. Fire Bell
3. APU FIRE light on the RWP illuminates
4. Red MASTER WARNING lights flash.

Question 10

How many fire extinguisher bottles does the APU have?

Answer 10

1

Question 11

Does a pilot-activated discharge of a fire bottle remove the green thermal discharge indicator?

Answer 11

No

Question 12

Pressing the APU FIRE PUSH button does what?

Answer 12

1. Load Control Valve Closes
2. Generator Relay Opens
3. Fuel Shutoff Valve Closes
4. Squib Arms (green SQUIB light)

Question 13

Can the APU be shutoff from outside the aircraft?

Answer 13

Yes, at the external DC power connection panel. There is an identical ‘APU FIRE’ button and ‘SQUIB” button. (there is not a ‘LOOP FAIL’ or ‘DIS’ light.

Question 14

What provides smoke and fire protection in the cargo compartment?

Answer 14

A photoelectric particle detector and an integrated temperature sensor (85C).

Question 15

If a smoke or fire condition is detected in the cargo compartment what warnings occur?

Answer 15

1. CARGO FIRE PUSH button illuminates
2. Triple Chime
3. CARGO FIRE light on the RWP
4. Red Master Warning light

Question 16

How does the cargo compartment fire extinguishing work?

Answer 16

Two fire extinguishing bottles, one discharges quickly (out 2 seconds) and the other discharges slowly over approximately 1 hour.

Question 17

What cockpit indication will you have if either cargo fire extinguisher bottle has discharged?

Answer 17

A white DIS light on the overhead fire panel.

Question 18

How is lavatory smoke and fire detection provided?

Answer 18

A smoke detector mounted to the lavatory ceiling.

A fire extinguisher bottle mounted above the lavatory waste bin with a wax capsule plug that melts away.

Question 19

If smoke/fire is detected in the lavatory what cockpit warnings are generated?

(before and after bottle)

Answer 19

• –BEFORE—
  1. Amber Master Warning lights.
  2. A single chime
  3. An amber LAV SMOKE CAS

(Wax capsule plugging bottle melts)

1. Red MASTER WARNING light
2. Triple Chime
3. Red LAV FIRE light on the RWP

Question 20

How is lavatory fire extinguishing provided?

Answer 20

A heat sensitive fire extinguisher bottle is mounted above the lavatory waste bin, a wax capsule melts away and discharges bottle.

Question 21

How do you test the Engine, APU, and Cargo Compartment fire protection and detection systems?

Answer 21

1. Hold test switch in FIRE/SQUIB position: all Fire Indications Occur and the green SQUIB light illuminate. This also checks for breaks in the fire loop.
2. If the test is not successful a LOOP FAIL light on the overhead panel will illuminate.
3. When the test switch is held in the FAIL/AGN position a Green AGN light illuminates for each fire bottle. A LOOP FAIL indicates the short circuit detection is working.