What is the APU in aviation?

What is the APU in aviation?

• A. An extra engine supplying electrical power and air conditioning while the aircraft is on the ground.
• B. A type of fuel used for auxiliary systems.
• C. A cabin seat adjustment device.
• D. A primary navigation computer.

Answer: (A)

The main idea here is what an APU actually is and what it does. An APU, or Auxiliary Power Unit, is a small turbine engine located in the aircraft that provides electrical power and bleed air when the main engines are not running. This lets the aircraft have power for lights, avionics, and other systems, and it can also supply air to run the air conditioning and environmental controls while the aircraft is on the ground. It can even provide the bleed air needed to start the main engines. It’s not a fuel type, not a cabin seat adjustment device, and not a primary navigation computer, so those options don’t fit the function of an APU.

The main idea here is what an APU actually is and what it does. An APU, or Auxiliary Power Unit, is a small turbine engine located in the aircraft that provides electrical power and bleed air when the main engines are not running. This lets the aircraft have power for lights, avionics, and other systems, and it can also supply air to run the air conditioning and environmental controls while the aircraft is on the ground. It can even provide the bleed air needed to start the main engines. It’s not a fuel type, not a cabin seat adjustment device, and not a primary navigation computer, so those options don’t fit the function of an APU.