Engine Fire Extinguishing

The engine fire extinguisher system consists of two engine fire extinguisher bottles, two
engine fire warning switches, two BOTTLE DISCHARGE lights, and an EXT TEST switch.
Either or both bottles can be discharged into either engine. The engine fire warning
switches are normally locked down to prevent inadvertent shutdown of an engine.
Illumination of an engine fire warning switch or ENG OVERHEAT light unlocks the engine
fire warning switch. The switches may also be unlocked manually.












Pulling the engine fire warning switch up:

  • Closes both the engine fuel shutoff valve and the spar fuel shutoff valve.
  • Closes the engine bleed air valve resulting in loss of wing anti–ice to the affected
    wing and closure of bleed air operated pack valve.
  • Trips the generator control relay and breaker.
  • Closes the hydraulic fluid shutoff valve. The engine driven hydraulic pump LOW
    PRESSURE light is deactivated.
  • Disables thrust reverser for the related engine.
  • Allows the engine fire warning switch to be rotated for discharge.
FIRE SWITCH LOCKED
FIRE SWITCH UNLOCKED