FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

Fusible plugs installed in aircraft wheels serve the critical function of melting at a specified elevated temperature. When the temperature in the wheel assembly reaches a certain level due to excessive heat caused by braking, the fusible plug melts, allowing the built-up air pressure inside the tire to escape. This controlled release of air helps prevent the tire from exploding due to increased temperature and pressure, ensuring the safety of the aircraft and its occupants.

Regarding the other options:

- Balancing the wheel is typically achieved by adding counterweights and adjusting tire alignment.

- Measuring air pressure is usually done using dedicated instruments like pressure gauges.

- Releasing excess air pressure is not the primary function of fusible plugs; they are designed to melt at a specific temperature to prevent catastrophic tire failures.