General Engines APU Wheel Well Cargo Compartment Lavatories EICAS Messages

Fire Protection - Wheel Well

Amendment: Addition of comments.

Wheel Well Fire Detection

The main gear wheel well has fire detection and warning only. There is no fire extinguishing system. The nose gear wheel well does not have a fire detection system.

The main gear wheel fire detection system consists of a single fire detector loop routed through both main gear wells.

MEL The Wheel Well Fire Detection and Warning System may be inoperative provided:

Brake temperature indications are verified normal prior to engine start or.
Brakes are cool prior to engine start.

Note 1: After takeoff, avoid the possibility of retracting a wheel overheated by dragging brakes by either:

Monitoring brake temperature indications (if installed) prior to gear retraction or
Leave gear extended for 20 minutes.

Note 2: In case of engine failure after V1, performance is the prime consideration. Landing gear should be retracted until obstruction clearance requirement has been met, then extended for a 20 minute cooling period.

Note 3: Pilots must consider the effects associated with delayed raising of the landing gear during winter operations from contaminated runways.

Wheel Well Fire Warning

The indications for a main wheel well fire are:

The fire bell sounds.
The master WARNING lights illuminate.
The WHL WELL FIRE warning light illuminates.
The discrete FIRE warning light illuminates.
The EICAS warning message WHEEL WELL FIRE displays.

The fire warning lights remain illuminated as long as the fire signal exists. The fire bell may be silenced by any of the following actions:

Extinguishing the fire and clearing the smoke.
Pushing either Master WARNING/CAUTION Reset Switch.

Note: The wheel wells do not have smoke detectors, only the fire detector loop. Therefore, smoke clearance does not influence the fire detection system.

Boeing The cessation of the wheel well fire warning does not guarantee that the fire is extinguished. In one example, after the gear was extended, the fire warning light extinguished but the fluid from a ruptured line continued to burn. Crews should treat a wheel well fire warning with the same respect as any other fire warning: Land at the nearest suitable airport and if conditions permit, leave the landing gear extended while enroute to that airport.

The fire warning bell rings intermittently for 2 seconds on, then 3 seconds off.

Cargo Compartment