What is the function of the APU fire protection system in flight?

The function of the APU fire protection system in flight is to automatically shut down the APU during a fire. This system is crucial for ensuring the safety of the aircraft and its occupants. By isolating the APU in case of a fire, it helps prevent the spread of flames or smoke to other parts of the aircraft, thus minimizing the risk of a more significant incident.

The automatic shutdown feature is part of an integrated safety protocol that allows the crew to focus on other critical aspects of flight management during an emergency. This is vital as APU fires can pose serious risks, especially when the aircraft is in flight and operational systems rely on APU functionality.

While crew notifications and emergency procedures are important, the primary role of the APU fire protection system focuses on proactive safety measures, such as automatically shutting down the APU to mitigate fire risks.