General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

When does the EEC select approach idle?

1. When the aircraft is on the ground

2. Automatically in flight under certain conditions

3. When the autopilot is engaged

4. Only during emergency landing

The correct answer is: Automatically in flight under certain conditions

The correct answer indicates that the Electronic Engine Control (EEC) selects approach idle automatically in flight under certain conditions. This selection typically occurs during the descent phase of an approach when the aircraft reaches a predetermined point where the thrust can be reduced to idle without compromising safety or performance. This allows for a smoother descent and approach, aligning with standard operating procedures focusing on fuel efficiency and maintaining optimal flight path. In this scenario, the automatic adjustment is crucial because it helps manage the engine's thrust settings dynamically based on the phase of flight and aircraft speed, optimizing the descent and approach to landing. The other options do not apply in this context. For instance, if the aircraft is on the ground, the engines would not typically select approach idle since that setting is relevant to the descent phase during flight. The engagement of the autopilot may influence descent profiles, but it is the specific flight conditions that lead to the EEC selecting approach idle. Similarly, using approach idle only during emergency landing does not reflect the normal operational procedures for managing aircraft thrust during standard approach phases.