FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsMedium
A technician is checking main landing gear tire inflation pressure prior to the first flight of the day. For the most accurate pressure reading, the tire should be checked when it is
- Acold, before the aircraft has been taxied or exposed to sun heating
- Bwarm, immediately after the aircraft returns from a flight
- Cat any temperature, since tire pressure does not vary significantly with temperature
- Dfully compressed with the aircraft jacked and the wheel off the ground
Show answer & explanationAnswer & explanation
Correct answer: A. cold, before the aircraft has been taxied or exposed to sun heating
Tire pressure should be checked when the tire is cold, meaning it has not been run or heated by the sun, because heat from taxiing or ambient sun exposure raises internal pressure and gives a false high reading. Checking cold ensures pressure matches the manufacturer's specified value under stable conditions.
Why the other options are wrong
- B. A warm tire from operation will read higher pressure than its true cold value.
- C. Tire pressure varies significantly with temperature per the gas laws.
- D. Jacking removes load but does not address temperature effects on pressure.
Cold Tire Pressure Check
Checking tire inflation pressure before the tire has been heated by operation or ambient sun, ensuring an accurate reading against manufacturer specifications.
- Heat from taxi/flight raises pressure readings falsely high
- Check before first flight or after sufficient cool-down
- Use manufacturer's cold inflation pressure chart
- Under-inflation causes shoulder wear, over-inflation causes center wear
Memory trick: Cold and calm gives the true tire exam.