Back to Center pedestal / Aft overhead panel.

FIRE PROTECTION.

Fireindication
1. ENG FIRE handle.
Left engine.
2. ENG FIRE handle.
Right engine.
3. AGENT LOW light.
Comes on to indicate fire extinguishing agent No 1 has been discharged.
4. AGENT LOW light.
Comes on to indicate fire extinguishing agent No 2 has been discharged.
5. LOOP TEST button.
Depress to test integrity of LOOP A.
6. LOOP B TEST button.
Depress to test integrity of LOOP A.
7. FIRE BELL OFF button.

The fire warning and protection system provides the means to detect and extinguish a fire in the engine nacelles and the Auxiliary Power Unit (APU).
The fire warning and protection system consists of fire detection, fire warning and fire extinguishing systems.
FIRE DETECTION system consists of
- Two sensing elements - fire detector loops - mounted in parallel (LOOP A and LOOP B).
- A fire detector amplifier.
- A three-position LOOP selector.
The fire detector loops are monitored by the fire detector amplifier. A fire or overheat condition must be detected simultaneously in both fire detector loops before the warning system is triggered.

FIRE WARNINGsystem consists of
- ENG FIRE lights located in the ENG FIRE handles on the upper instrument panel.
- LOOPA and LOOP B lights on the overhead panel.
- FIRE DETECTOR LOOP caution on the annunciator panel together with MASTER CAUTION.
- Aural warnings, bell and voice, from the central aural warning unit and a FIRE BELL OFF button.

FIRE EXTINGUISHING system consists of
- Two fire extinguisher agent containers.
- Control circuits and AGENT LOW lights.
- ENG FIRE handles on the upper instrument panel and APU FIRE AGENT discharge switches on the overhead panel and the APU ground control panel.
Each container has separate discharge heads and distribution lines to each engine and to the APU.

LAVATORY FIRE DETECTION
A lavatory smoke detection system is installed. It consists of a smoke detector, which is installed in the ceiling of each lavatory, a local indicator light outside each lavatory, a control panel installed in the ceiling in front of the forward CA seat, and an additional horn in the aft part of the cabin.
There is no duplication of the lavatory smoke warning on flight deck.

LAVATORY FIRE EXTINGUISHING.
The lavatories are equipped with a fire extinguishing bottle. The bottle discharges automatically into the waste container when fire occurs.

CARGO FIRE SYSTEM.
The cargo compartments are protected by a semi-automatic smoke and fire detection and suppression system. The system is designed to detect and suppress a smoke and/or fire condition in either the forward, mid or aft cargo compartment, and will provide both aural and visual annunciation to the flight crew if activated.

ENGINE FIRE
Fireindication
Engine fire is indicated by a light in he corresponding fire handle together with a fire bell and aural warning.

If the fire stops, the light will go out.
Fireindication The two corresponding LOOP lights will also illuminate. Fireindication
Pulling the fire handle will
  • Silence the aural warning.
  • Trip the generator field control relay.
  • Close the engine fuel fire shutoff valve.
  • Close hydraulic fire shutoff valve.
  • Close the pneumatic crossfeed valve.
  • Turning the handle either left or wright will discharge fire extinguisher agent from container 1 or 2.
In the above example, there is a fire/overheat in the right engine. After pulling and rotating the handle the light in the fire handle is still on. The amber AGENT LOW light for no.1 container is on, indicating that that the extinguishing agent has been discharged. Time to rotate the handle in the opposite direction to discharge the other container into the same engine.
CARGO FIRE
Fireindication
DET lights illuminate when a detector in the respective Loop senses smoke.
FIRE light illuminates steady when a compartment fire is detected. Cargo fire horn will also come on.
Fireindication
In both cases the corresponding part of the CARGO FIRE/SMOKE DETECTOR LOOP ANNUNCIATOR light, on the left pilot instrument panel, will come on.
Back to Center pedestal / Aft overhead panel.