What should be monitored to ensure APU effectiveness during operations?

Monitoring temperature conditions and fuel levels is essential to ensure the effectiveness of the Auxiliary Power Unit (APU) during operations. The APU plays a critical role in providing energy for starting the main engines and powering onboard systems while the aircraft is on the ground.

Temperature conditions are vital because the APU must operate within specific temperature ranges to function efficiently. High temperatures can lead to overheating, while excessively low temperatures could affect its performance and reliability.

Fuel levels are equally important, as the APU requires a consistent fuel supply to generate power. Insufficient fuel can result in the APU shutting down or operating inefficiently, which compromises its ability to provide necessary power and can create operational delays or issues during missions.

In contrast, solely monitoring fuel levels would not provide a complete picture of the APU's operational status. Engine performance alone does not address the crucial aspects of APU function, and altitude and weight do not directly relate to APU efficiency or effectiveness. Therefore, keeping an eye on both temperature conditions and fuel levels ensures that the APU operates effectively during all phases of operation.