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

What does the green "AVAIL" light signify after starting the APU on the CRJ-700/900?

1. The APU is malfunctioning

2. The APU GEN is available for electrical loading

3. The APU is not ready for use

4. The APU is powering other systems

The correct answer is: The APU GEN is available for electrical loading

The green "AVAIL" light on the CRJ-700/900 indicates that the Auxiliary Power Unit (APU) generator is available for electrical loading. When the APU is started and operational, this light confirms that the APU has successfully reached a state where it can supply power to the aircraft's electrical systems. This signal is crucial for flight operations, as it allows the crew to utilize the APU's electrical output for various functions while on the ground, such as powering the cabin and instrument lights or starting the main engines without relying on ground power. This indicator plays a vital role in ensuring that the crew is aware of the APU's readiness and capability, thereby enhancing situational awareness and operational efficiency during ground operations and preparations for the flight.