Why don’t aircraft use run-flat tyres?

Question

Tyre failures on aircraft during takeoff are fairly common, and are usually (though not always) caused by flat or underinflated tyres (via the overdeflection and overheating experienced by tyres with abnormally low internal pressures). If an aircraft tyre fails during takeoff, this is dangerous in several different ways:

• Flying tyre fragments can damage other parts of the aircraft, as well as, potentially, other nearby aircraft or ground personnel.

• Wheels with blown tyres are useless for braking, thus greatly increasing the chance of a runway overrun should it become necessary to reject the takeoff.

• A tyre failure(s) can greatly degrade directional control, especially on smaller aircraft that only have a few wheels to begin with.

• A failed tyre dragging on the runway can easily heat up enough to ignite and burn, dooming the aircraft if the crew then retract the landing gear without knowing that said landing gear is on fire.

Run-flat tyres are designed to remain useable even in the event of a total loss of internal pressure (generally by incorporating an internal weight-bearing skeleton inside the tyre’s air chamber); given the potentially catastrophic consequences of a flat tyre failing during takeoff, why don’t aircraft use run-flat tyres?

Answer 1

The same reasons that run-flat tires aren't more common on cars or trucks are amplified with aircraft.

• They're more expensive and can wear out faster. They will also be much heavier. This has to be traded against the cost of an occasional flat tire.
• They typically have a maximum speed when flat. Aircraft tires need to operate at much faster speeds than vehicle tires. Many of the examples you provided were made worse by under-inflated tires.
• They typically have very limited range when running flat. Again, many of your examples involved under-inflated tires. If they left a regular tire to burst, the same would happen to a run-flat tire.
• Many tire failures are due to the tires bursting, not just a simple puncture that makes them go flat. A run-flat design will not help in this case, and may even make the fragments more dangerous.

All of your airliner examples were on pretty old aircraft models, and many included additional factors. Regulations and procedures change over time in response to these sorts of accidents. When properly maintained and operated, aircraft are designed so that a disintegrating tire won't cause serious hazards.