| Overheat / Fire Protection Panel |
APU Fire Warning Switch
Illuminated –
Note: Master FIRE WARN lights illuminate, fire warning bell sounds, and in
the main wheel well the APU fire warning horn sounds (on the ground only),
and the APU fire warning light flashes.
Down – Normal position. Mechanically locked down if there is no fire signal.
Illuminated –
- Indicates a fire in the APU
- Unlocks the APU fire warning switch.
Note: Master FIRE WARN lights illuminate, fire warning bell sounds, and in
the main wheel well the APU fire warning horn sounds (on the ground only),
and the APU fire warning light flashes.
Down – Normal position. Mechanically locked down if there is no fire signal.
Up –
Rotate (left or right) –
- Arms the APU extinguisher circuit.
- Closes the fuel shutoff valve, APU bleed air valve, and APU inlet door.
- Trips the APU generator control relay and breaker.
- Allows the APU fire warning switch to rotate.
Rotate (left or right) –
- Discharges the APU fire bottle.
Aft Electronic Panel 700/800/900
