Upon detection of a fire in which area will the system automatically shut down the APU if it is operating?

The automatic shutdown of the Auxiliary Power Unit (APU) upon detecting a fire in a certain area is a critical safety feature designed to prevent further damage and ensure the safety of the aircraft and its occupants. The midwing area, where the APU is often located, is strategically important for the aircraft's operation and safety.

When a fire is detected in the midwing area, the system is designed to prioritize the shutdown of the APU to eliminate the risk of fire spreading or causing additional hazards. Shutting down the APU helps to stop the fuel flow and electrical systems associated with it, potentially preventing a catastrophic event.

While fires in other areas, such as the engine bay, nacelle area, or fuselage, may also initiate various emergency protocols, the specific design and location of the APU's safety features mean that the midwing area is the predetermined zone for an automatic shutdown response. This is based on engineering assessments of fire risks and operational protocols that focus on minimizing hazards related to the APU.