Which of the following tasks does the APU NOT perform?

The auxiliary power unit (APU) plays a vital role in providing various support functions for an aircraft while it is on the ground. It supplies electrical power, which is crucial for operating systems when the engines are not running. Additionally, the APU facilitates the starting of the aircraft's main engines by providing the necessary high-pressure air. It also enables air conditioning to maintain a comfortable environment in the cabin and cockpit while the aircraft is on the ground, which is particularly important for passenger comfort and equipment cooling.

However, one task that the APU does not perform is assisting in takeoff performance. Takeoff involves the main engines working at full throttle to generate the necessary thrust for the aircraft to become airborne. While the APU supports ground operations and engine start, it is not involved in the actual performance of the aircraft during takeoff. The propulsion and performance during takeoff are solely managed by the main engines, and the APU's functions do not directly contribute to that phase of flight.