Fire

Question 1

Fire loops, how many, how do they work?

Answer 1

Engine and APU have 2 identical loops, A & B, mounted in parallel to a FDU (Fire Detection Unit) that measure resistance.

The engine has 3 fire sensing elements:
Pylon nacelle
Engine core
Engine fan section

APU has 1 sensing element in the APU compartment

Question 2

How many fire extinguishing bottles in the fire section system?

Answer 2

4 engine (2 each side)
1 APU
1 Cargo
1 lav bin