26- Fire protection Flashcards
Fire and smoke protection system includes?
- fire and overheat section in engines/apu
- smoke detection in cargo compartments, avionics bay and lavs
- fire extinguishing for cargo compartments, engines, apu and lavs.
- portable fire extinguishers
What do each engine and apu have for the fire /ovht detection system?
- 2 identical loops in parallel
- a FDU
What makes up FD loops? Where are they installed?
- 3 fire sensing elements in: the pylon nacelle, eng core, eng fan
- 1 fire sensing element in the APU compartment
How many bottles for APU? how many squibs? APU extinguishing on the ground? In the air?
- 1 bottle, 2 squibs
- on ground, if fire detected, APU automatically shuts down and discharges bottle
- in air, flight crew controls discharge
When do fire warnings get sent from loops?
- Both loops A and B send signal
- 1 loop sends signal and other failed
- Breaks occur in both loops with 5s
- Test performed from FIRE panel
Loop fault Caution appears if fire loop fails
What things happen when Eng fire pb pressed (8 things)?
- Silences aural warning
- Arms squibs
- LP Fuel valve closes
- Hydraulic shut off valve closes
- Eng bleed valve closes
- Close pack flow control valve
- Cuts power to FADEC
- Deactivates IDG
What things happen when APU fire pb pressed (7 things)?
- Silences aural warning
- Shuts down APU
- Arms squib
- Closes LP fuel valve
- Shuts off APU fuel pump
- Closes APU bleed valve, closes x-bleed
- Deactivates APU Gen
What is APU shut off pb?
Used for manual apu emergency shutdown by ground crew
Cargo smoke detectors? How many in each compartment? When does cargo warning happen?
2 smoke detectors in fwd
4 smoke detectors in aft
Each detector linked to 1 of 2 loops in each bay (dual loop principle).
Warning if:
- both detectors detect smoke
- 1 detects smoke and other inop
Fire extinguishing in cargo?
1 bottle supplies 2 discharge heads (1 fwd,1 aft), supplies 3 nozzles (1 fwd, 2 aft)
Amber discharge light comes on when Bottles emptied (within 60s)
