How does the APU fire protection system respond to an APU fire?

The APU fire protection system is designed to enhance safety by automatically detecting and responding to APU fires, particularly when the aircraft is on the ground. In the event of a fire detection within the APU compartment, the system activates automatically to discharge fire extinguishing agents, effectively mitigating the risk of fire spread and damage. This automatic response is crucial because it allows for rapid action without the need for immediate pilot intervention, which can be critical in an emergency situation.

While manual discharge is an option when needed, the automatic function on the ground is a key safety feature of the APU fire protection system. This not only helps in managing APU fires efficiently but also ensures that crew members can focus on other emergency protocols and passenger safety.