Aircraft tires are one of the most underrated critical parts of an aircraft and are vital to aircraft function and safety. They ensure that taxiing, takeoffs, and landings and can be accomplished efficiently and safely. It is imperative that close attention is paid to the condition of the tires regularly.
Because aircraft tires operate at such high extremes of pressure, load, and speed, their care and maintenance are critically important. The most important maintenance actions that can be taken to maximizing tire utilization and minimize tire-related risks are to maintain proper tire inflation pressures and to regularly inspect the tire treads.
Making sure that the aircraft tires are maintained and inflated according to the proper inflation pressure is a crucial part of preflight and routine service checks. Improper tire pressure is usually the cause of 90% of tire failures. If the pressure is too low the tire may move or creep around the wheel or can damage the bead while over inflation will cause excessive wear.
Tire pressures for larger aircraft usually exceed 200 psi and can exceed 300 psi in some aircraft. Inflation pressure should be checked daily at ambient temperatures. Temperature changes affect the tires pressures on a daily basis. A pressure change of about 1% in the tire can be caused by a temperature change of 5°F in the ambient air. A calibrated pressure gauge should always be used to measure inflation pressure to prevent inaccuracies in the measurement. Some newer aircraft are able to show real-time tire pressure in the aircraft cabin.
Nitrogen is typically used to inflate tires. Because it is an inert gas, it is noncombustible and will not degrade the liner material due to oxidation. The gas also works well at absorbing shocks and in supporting the aircraft weight. After inflation, the tire inflation valve must always be fitted with a valve cap. This cap prevents dirt from entering the inflation valve and slows down the loss of pressure in case of valve failure.
Pilots and technicians must check the tire treads for any nicks, wear, cuts, bulges, leaks tread depth and for any foreign materials imbedded in the tire both during preflight checks and after every flight. The treads should be inspected visually, and if the tread has worn down to the base of any groove or to the minimum depth specified by the aircraft manufacturer then the tires should be replaced. Any inner ply material showing through the tire tread is a dangerous condition and the tire must be replaced immediately.
If it is discovered that any of the inspections are unsatisfactory, then maintenance action will be required in accordance with what is contained in the Aircraft Maintenance Manual (AMM), or as approved by the appropriate authority.
The storage of aircraft tires is just as important as the maintenance. Tires should be stored in a cool, dry and reasonably dark location free from direct sunlight, dirt, and weather. Room temperatures above 90°F are to be avoided. Tires should also be stored vertically on tire racks off of the ground.
Aircraft tires should be stored away from fluids such as jet fuel, oil, gasoline, solvents, and from any other hydraulic or hydrocarbon-based fluids. Any contact or long-term exposure to the fluid vapors can cause the rubber in the tire to disintegrate. If tires become contaminated, they should be washed off with alcohol, soap, and water.
For aircraft in storage, tire covers placed over the tires can help to maintain the tire shape and keeps it protected from damage and from the effects of the environmental conditions.
RVSM isn’t all that needs inspected and.
Here’s all the other equipment that needs calibrated and tested.