Do not stand directly in front of the intake
During a normal or an emergency landing, the
landing gear is an item of considerable concern. With
the added weight and landing speeds of modern
aircraft, and because of the extreme braking required on
shorter runways, overheated brakes and wheels are a
common occurrence. You, as a fire fighter, must have a
thorough understanding of the hazards created by
overheated brakes, as well as the techniques and
equipment used with this type of emergency.
Overheated aircraft wheels and tires present a
potential explosion hazard because of built-up air
pressure in the tires, which is greatly increased when
fire is present.
To avoid endangering the crews
needlessly, all nonessential personnel should evacuate
the area. The recommended procedure for cooling
overheated wheel, brake, and tire assemblies is to park
the aircraft in an isolated area and allow the assemblies
to cool in the surrounding air. Using cooling agents,
such as water, is not recommended unless absolutely
necessary due to increased hazards to personnel near
the overheated assembly. Most aircraft operating
manuals for propeller-driven aircraft recommend that
flight crews keep the propeller turning fast enough to
provide an ample cooling airflow.
Most major jet,
propeller-driven, and turboprop aircraft now have
fusible plugs incorporated in the wheel rims. These
fusible plugs are designed to automatically deflate the
tires. (Failure of fusible plugs to function properly has
Releasing the tire pressure reduces the
pressure on the wheel, and thus eliminates the
possibility of explosion.
The use of CO2 for rapid cooling of a hot
because of the rapid change in temperature.
When responding to a wheel fire or hot brakes as a
member of the emergency crew, you should approach
the wheel with extreme caution in a fore or aft direction,
never from the side in line with the axle.
temperatures may not be reached until 15 to 20 minutes
after the aircraft has come to a complete stop. See
WHEEL ASSEMBLY FIRES
The following types of fires and hazards may occur
around an aircraft wheel assembly:
The heating of aircraft wheels and tires
presents a potential explosion hazard, which is greatly
increased when fire is present. The combination of
increased stress on the brake wheel assembly,
additional tire pressure, and the deterioration of
components by heat may cause an explosion.
explosion is likely to propel pieces of the tire and/or
metal through the air at high speeds.
assembly fires are grease, hydraulic fluid, bearing
lubricants, and tire rubber.
Grease and bearing lubricant fires. When
ignited, wheel grease fires can be identified by long
flames around the wheel brake/axle assembly. These
fires are usually small and should be extinguished
quickly with Halon 1211 or water fog.
Rubber tires. Rubber from the tires may
ignite at temperatures from 500°F (260°C) to 600°F
(315°C) and can develop into an extremely hot and
destructive fire. Halon 1211 or water fog should be
used as early as possible to extinguish the fire.
Reignition may occur if the rubber sustains its
autoignition temperature or if the rubber is abraded and
the fire is deep-seated.
A broken hydraulic line may result in the
misting of petroleum-based fluids onto a damaged or
Figure 12-15.Danger zones and attack zones in combating
(Attack the fire from fore and aftdo not
attack from the side).