To what flight altitude can the APU provide maximum electrical power?

The Auxiliary Power Unit (APU) of the A320 is designed to provide electrical power and bleed air while the aircraft is on the ground or in flight. The correct answer indicates that the APU can deliver maximum electrical power at any altitude up to the aircraft's maximum flight altitude. This is important because the APU's primary function is to support aircraft systems when the main engines are not operational, particularly during ground operations.

In flight, the APU continues to be effective, ensuring that necessary electrical loads can be met even as the aircraft reaches higher altitudes. While performance might be influenced by various factors such as ambient temperature and load, the APU itself is rated to operate efficiently and provide its full electrical capacity up to the aircraft's maximum operational altitude, which can vary depending on airplane configuration and operational limits but generally aligns with the aircraft's certified maximum flight altitude.

This operational capability emphasizes the versatility of the APU, allowing for a seamless transition of power needs throughout various phases of flight, ensuring that all systems remain functional without reliance solely on the main engines or external ground power sources.