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

Why is the operating time limited when only battery power is available on the ground?

1. The battery drains quickly

2. AC powered fans for EICAS displays are not operational

3. The EICAS system has a backup power source

4. The lights draw too much power

The correct answer is: AC powered fans for EICAS displays are not operational

The correct answer highlights that when operating on battery power alone on the ground, the auxiliary systems, including the fans necessary for the Engine Indication and Crew Alerting System (EICAS) displays, are not operational. This limitation affects the overall functionality of various systems that rely on those displays for critical information. When the aircraft is powered solely by its batteries, not all systems are able to draw power efficiently. The EICAS requires cooling fans to ensure proper operation and display clarity. Without AC power, these fans cannot function, leading to potential overheating or inaccurate readings. This reduces the operational capability of the aircraft, necessitating a limit on the time the aircraft can function on just battery power. Thus, the effectiveness of monitoring engine parameters and alerts crucial for safe ground operations decreases significantly, which is why the operating time is restricted. The battery's capacity is also a concern; however, the primary focus in this scenario is on the operational capability of essential flight systems.