Ryanair Initial Practice Exam

What does the Auxiliary Power Unit primarily provide for the aircraft?

1. Backup water supply

2. Electrical power

3. Communication support

4. Navigation assistance

The correct answer is: Electrical power

The Auxiliary Power Unit (APU) primarily provides electrical power for the aircraft when the engines are not running. This is crucial for powering various systems on the aircraft, such as lights, avionics, and cabin climate control, allowing for essential operations to continue while on the ground or during engine start. The APU ensures that the aircraft can maintain functionality without relying on external ground power sources, making it particularly important during pre-flight preparations and when the aircraft is at the gate. This capability enhances the overall efficiency and safety of aircraft operations. Other options, such as backup water supply, communication support, or navigation assistance, are not primary functions of the APU, as those systems are supported by different components of the aircraft infrastructure.