Fire Protection Flashcards
Overheat Detector OVHT DET switch
Normal- both loop A and B are active
A- detection loop A active
B- detection loop B active
Fire warning BELL CUTOUT switch
When you push:
- extinguishes the master FIRE WARN lights
- silences the fire warning bell
- Silences the remote APU fire warning horn (ground only)
- resets system for additional warnings
EXT TEST switch
1 or 2- tests bottle discharge circuit continuity for all three extinguisher bottles
FAULT/INOP and OVHT/FIRE switch
FAULT/INOP- tests fault detection circuits for both engines and APU
OVHT/FIRE- tests overheat and fire detection loops on engines, APU, and wheel well fire detector
APU FIRE SWITCH (RED)
Red:
- indicates APU fire
- Unlocks APU fire switch
What happens when you pull the APU fire switch? And then rotate it?
- arms the APU extinguisher circuit
- Closes fuel SOV, APU bleed air valve, APU inlet door
- trips generator control relay and breaker
- Allows APU fire switch to rotate
When you rotate it, it discharges the APU fire bottle
Engine Fire Switch (red)
it is mechanically locked if no fire signal
- indicates fire in related engine
2. unlocks related engine fire switch
What happens when you pull the engine fire switch?
- Arms one squib on each engine fire extinguisher
- closes fuel SOV
- closes hydraulic SOV
- closes engine bleed air valve
- disables thrust reverser
- trips generator control relay and breaker
- deactivates engine driven hydraulic pressure LOW PRESSURE light
- allows engine fire switch to rotate
Fire Switch Override
Push- unlocks the engine fire switch
ENG OVERHEAT light(amber)
indicates overheat in related engine
FAULT light (amber) With overheat detector switch in NORMAL or overheat detector switch in A or B
in NORMAL:
indicates both detector loops for an engine have failed
in detector switch in A or B- indicates the selected loop for an engine has failed
Wheel WELL Fire warning light (red)
indicates fire in main gear wheel well
the FIRE WARN light and bell also sounds
Engine BOTTLE DISCHARGE light (amber)
related fire extinguisher bottle has discharged
APU DET INOP light (amber)
APU detector loop has failed
APU BOTTLE DISCHARGE light (amber)
APU extinguisher bottle has discharged
EXT TEST lights (green)
EXT switch positioned to 1 or 2 and circuit continuity is normal
EXT Test lights (green) for cargo
indicates the the cargo fire TEST switch is pushed and fire bottle discharge squib circuit continuity is normal
cargo DETECT SELECT Switches (NORM, A, B)
NORM- detection loop A and B active
A- loop A active
B- loop B active
Cargo Fire ARMED Switches (momentary action) (MAIN, FWD, ARMED)
PUSH-
MAIN ARMED- commands pack to low flow
FWD ARMED- extinguisher armed for FWD compartment
AFT ARMED- extinguisher armed for AFT cargo compartment
Cargo Fire (MAIN FWD AFT) Warning lights (red)
- at least one detector in each loop detects smoke
or - with power failed in one loop, at least one detector on the remaining loop detects smoke