FAA Powerplant Written Practice Test

Fire protection systems are mandatory on which component?

1. Main engines

2. Auxiliary Power Units

3. Landing gear

4. Fuel tanks

The correct answer is: Auxiliary Power Units

Auxiliary Power Units (APUs) are critical components that provide electrical power and pneumatic pressure for starting main engines and other functions when the aircraft is on the ground. Given their operation often involves combustive processes and fuel, they are susceptible to fire hazards. As a result, fire protection systems are mandated for APUs to enhance safety and minimize the risk of fires, which can lead to catastrophic consequences during ground operations. Each of the other choices does have its own considerations for fire safety, such as the main engines and fuel tanks being monitored and protected due to the inherent fire risk they present. However, the specific regulatory requirements regarding fire protection systems are particularly emphasized in APUs due to their unique operational environment and potential for fire incidents. This requirement reflects the understanding of safety risks associated with APUs, thereby making the fire protection systems a necessary component for ensuring safe aircraft operation.