Daily Aircraft Tyre Pressure Checks Important: Goodyear

Goodyear Aviation product support manager Robert Robson has emphasised the importance of daily aircraft tyre pressure checks. Aviation tyres' design and construction differ from automobile tyres, and though it is important to maintain the correct pressure in car tyres, proper aircraft tyre pressure is the most important factor in aircraft preventive maintenance. As a result, pilots and maintenance personnel must resist the temptation to follow the same schedule they would use in checking their cars' tyres to determine that their aircraft tyre pressure is correct, advises Robson, who regularly teaches aviation industry authorised inspection classes and has ten years of aviation tyre experience.

“Aircraft tyre pressure should never be taken for granted,” Robson said. “High pressures, high loads, and the different designs of aircraft tires and wheels often cause assemblies to lose pressure faster than those for cars.”

Overinflated tyres can suffer uneven tread wear, reduced braking traction, increased susceptibility to cutting, in addition to causing greater stress on wheels and landing gear. Underinflated tyres can wear unevenly and will experience increased stress and flex heating, which shortens tire life and can lead to tyre failure.

Robson advises daily aircraft tyre pressure checks, preferably before first flight: “Check pressures when the tires are at ambient temperatures,” he said. “Tyre temperatures can increase 200°F during aircraft operation, and every increase of 5ºF results in approximately a 1 per cent pressure change.” Therefore aircraft tyre pressure should never be reduced when the tyres are still hot.

Robson said tyres should not be placed in service until they have been inflated for at least 12 hours after mounting. “All tyres, particularly bias, grow after their initial mounting. The larger volume of the tyre results in a pressure drop, and thus the tire must be checked and re-inflated if necessary,” he said. After completing the 12-hour stretch, it is highly recommended to perform a 24-hour diffusion check to ensure the tyre/wheel assembly is holding pressure within the limits of 5 per cent per day, since there are numerous potential sources of pressure loss within the assembly. Both of these steps are important to help ensure the tyres are not underinflated before entering service.