Originally Posted by
jockey69
considering potency of the risks involved in a wheelwell fire...i would recommend having fire/overheat sensors in the wheels and pressure transducers in the tires to enable reject a take off...and Halon bottles in the wheelwell i believe would be a safer bet rather than just rely on ram air to extinguish a fire/overheat condition.am
J69, your belt and suspenders approach is not without merit, yet realize tire failures are regular occurrences that typically have no more consequence than a maintenance write up, replacement of the offending bits, and inspection. In fact, Airbus recommends continuing the takeoff under V1 for a single tire failure. Boeing also states their aircraft can takeoff and land safely with one flat tire per bogie. Statistics are sparse in this area - airlines are not required to issue an incident report on a tire failure without collateral damage.
In cases of a locked brake, there will eventually be an EICAS/ECAM warning generated (temperature limit reached), along with an immediate tendency to pull in the direction of the lock, but an RTO based on temps alone would be unlikely since the heat rise lags the physical event. Once airborne, lowering the gear is simple and effective in getting things cooled off. History has shown at or near V1 RTOs due to brakes or tires can lead to overruns.
am i missing something ?
Yes, an earlier reply regarding Halon and wheel well fires.
Halon will not put out a magnesium fire and due to wheel wells being poorly closed compartments, the concentration levels needed for fire suppression would be difficult to sustain - the bottles would need to be very large. Halon also reacts poorly with hot metal, including that hot set of steel brake rotors and disks that most likely was the heat source for initiating the fire/overheat condition in the first place.