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

What triggers auto-relight?

1. Continuous engine operation

2. Flameout or sub-idle stall recovery

3. Thrust lever position beyond 80%

4. Flaps set to takeoff position

The correct answer is: Flameout or sub-idle stall recovery

Auto-relight is primarily triggered by conditions that indicate a need to restore engine ignition after a loss of combustion, such as a flameout or a sub-idle stall. A flameout occurs when the engine stops producing thrust due to a disruption in the combustion process, which could be caused by various factors such as changes in airflow, fuel supply issues, or environmental conditions. When a flameout happens, auto-relight mechanisms in modern jet engines are designed to automatically initiate a relight sequence. This is a crucial safety feature that helps the pilot restore engine operation without requiring manual intervention. It enhances flight safety by reducing the risk of prolonged engine failure during critical phases of flight, such as in the event of an uncommanded flameout. While continuous engine operation is important for normal functioning, it does not specifically trigger the auto-relight procedure. The thrust lever position beyond 80% primarily relates to engine management and performance but does not initiate auto-relight. Setting the flaps to the takeoff position concerns aircraft configuration for flight stages rather than engine relighting procedures.