What is the minimum height for autothrottle use during landing?

The minimum height for autothrottle use during landing is 50 feet. This altitude is critical because it represents a point in the approach phase where the autothrottle system can effectively manage engine thrust to maintain the desired airspeed, especially during critical phases of landing.

Using autothrottle at this height allows the pilot to have a safety margin while relying on automation to maintain the correct speed as the aircraft transitions from the approach to landing. By utilizing autothrottle up to this point, pilots can focus on other aspects of the landing process, such as controlling descent rate and ensuring proper alignment with the runway.

Choosing a threshold lower than 50 feet could lead to risks associated with insufficient pilot intervention at a crucial moment when manual control might be required, while a higher threshold could result in unnecessary workload during a complex phase of flight. Therefore, 50 feet is established as the minimum safe altitude for autothrottle functionality, aligning with best practices in aviation safety and operational standards.