8. Fire Protection

Question 1

How is a fire detected?

Answer 1

Prior to BB-1444, three photoconductive detectors per engine feed a control amplifier to activate appropriate FIRE ENG light. (ZGD 1412)

BB-1444 and after, a temperature sensing cable activates L or R ENG FIRE light (ZMW 1460)

Question 2

Will the fire detecting system still work if the fire goes out?

Answer 2

Yes (assuming the system isn’t damaged)

Question 3

How is the fire extinguisher delivered within the nacelle?

Answer 3

1 bottle per engine supply 3 spray bars per engine compartment. 1 squib per bottle incorporates a pyrotechnic charge which releases entire contents. The squib is fired by depressing the switch-light on glareshield

Question 4

What does the 3 lens control indicator on glareshield indicate?

Answer 4

Red- ENG FIRE PUSH TO EXT (L or R)

Amber- D- extinguisher has been discharged, supply empty

Green- OK- confirms circuit continuity during test function

Question 5

Where are engine fire extinguishers located?

Answer 5

In the wheel wells

Question 6

When are the detection and extinguishing systems operable?

Answer 6

Detection when electrical power is applied to aircraft.

Extinguishing is on hot battery bus