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

When is the autothrottle (A/T) engaged during stall protection?

1. Below Vmin

2. Above MCP speed

3. When armed

4. During takeoff only

The correct answer is: When armed

The autothrottle (A/T) system is a critical component in modern aircraft that assists pilots in maintaining optimal performance and safety, particularly during critical flight phases such as stall protection. The system is designed to regulate engine thrust automatically in response to the aircraft's speed and configuration. When the autothrottle is engaged during stall protection, it is essential that the system is in an "armed" state. In this mode, the A/T is prepared to adjust the thrust to help prevent the aircraft from entering a stall condition. Once certain thresholds related to airspeed and configuration are detected, the A/T can activate to increase thrust as needed to maintain control and delay the onset of a stall. This concept underlines the importance of the A/T being armed, as it ensures that the system is ready to intervene when the aircraft approaches critical speed limits. Thus, having the A/T armed allows for timely and appropriate thrust management to protect against stalls. The other options focus on specific speed thresholds or conditions which do not align with the operational function of the autothrottle related to stall protection as effectively as the armed state. This highlights the necessity of having the system in the correct condition to respond proactively during critical flight scenarios.