PSA Airlines Canadair Regional Jet Systems (PSA-CRJ) Practice Exam

What is the consequence of the APU primarily supplying electrical power?

1. Pneumatics become the priority

2. It reduces battery load

3. Electrical power is secondary

4. Pneumatics can only operate when electrical power is available

The correct answer is: It reduces battery load

When the Auxiliary Power Unit (APU) primarily supplies electrical power, it has a significant impact on the overall electrical and pneumatic systems of the aircraft. The key consequence is that it reduces the load on the aircraft's batteries. By utilizing the APU to generate electrical power, the demands placed on the batteries during ground operations or while the engines are off are minimized. This not only extends battery life but also ensures that there is adequate energy available for other essential systems without overtaxing the batteries, especially during periods when the aircraft is stationary and its engines are not running. This operational efficiency is crucial, as it allows for better management of energy resources throughout the aircraft. Ensuring a lower battery load not only enhances reliability but also supports the effective function of critical onboard systems that might rely on this available power supply.