Auxiliary Power Unit (APU)

Auxiliary Power Unit (APU)

What is an Auxiliary Power Unit (APU)?

Powering Aircraft Systems

The Auxiliary Power Unit (APU) provides power to aircraft systems ensuring functionality.

An Auxiliary Power Unit (APU) is a device located on an aircraft that provides energy for various functions other than propulsion. It is essentially a small engine that powers a generator.

• Uses on Aircraft: The APU is primarily used to power an aircraft’s electrical systems on the ground, to start the main engines, and to provide cabin heating or air conditioning when the main engines are not running.
• Operational Independence: APUs allow aircraft to be operationally independent at airports, as they can generate power without needing ground-based facilities.
• Location and Operation: Typically located at the rear of the fuselage, the APU can be operated in flight or when the aircraft is on the ground.

The Auxiliary Power Unit is a crucial component in modern aircraft, providing essential power for various systems, especially when the main engines are not in use.