Fire Protection

Question 1

When the flight crew pushes the ENG FIRE PB, the pushbutton is released and sends an electrical signal that performs the following for the corresponding engine:

Answer 1

‐ Silences the aural fire warning
‐ Arms the fire extinguisher squibs
‐ Closes the low-pressure fuel valve
‐ Closes the hydraulic fire shut off valve
‐ Closes the engine bleed valve
‐ Closes the pack flow control valve
‐ Cuts off the FADEC power supply
‐ Deactivates the IDG.

Question 2

When the flight crew pushes the APU FIRE PB, the pushbutton is released and sends an electrical signal that performs the following for the corresponding engine:

Answer 2

‐ Shuts down the APU
‐ Silences the aural warning
‐ Arms the squib on the APU fire extinguisher
‐ Closes the low-pressure fuel valve
‐ Shuts off the APU fuel pump
‐ Closes the APU bleed valve and X bleed valve and deactivates the APU generator.