What is the condition required for the ATTCS system to engage?

The ATTCS (Automatic Takeoff Thrust Control System) is designed to automatically adjust engine thrust in the event of an engine failure during takeoff. For the ATTCS system to engage, the thrust levers must be positioned in the Takeoff/Go-Around (TOGA) detent, indicating that the aircraft is prepared for takeoff with maximum thrust settings. The system primarily activates when there is an engine failure detected during this critical phase, ensuring that the aircraft can maintain adequate performance and climb capability with the remaining operational engine.

This specific combination of throttle position and engine status is crucial, as it ensures that ATTCS provides the necessary thrust adjustments to compensate for the loss of an engine, which is essential for maintaining safety during high-demand operations like takeoff. Other scenarios, such as having the throttle at flight idle, the flaps set for takeoff, or having an aircraft weight above maximum landing weight do not meet the criteria for engagement of the ATTCS system, as they do not involve the simultaneous need for maximum thrust due to engine failure.