What are the assumptions made regarding maximum abort speed?

The concept of maximum abort speed is critical for decision-making in flight, especially during takeoff or landing. The assumption of a 3-second reaction time to recognize and select idle power is valid because it reflects a realistic scenario in which a pilot must process information, decide on an action, and then execute that action. This timeframe allows for muscle memory and cognitive response, which is essential when responding to emergencies or aborting takeoff.

In practice, the moment a critical failure occurs, the pilot's reaction time—taking into account initial awareness and decision-making—is often longer than just Instantaneous recognition. It encompasses the moment it takes to recognize the failure, evaluate the situation, and then throttle back to idle. Thus, using a 3-second window is appropriate for calculating safe operational limits such as the maximum abort speed during an ascent or approach.

Other assumptions regarding maximum abort speed can involve factors like deceleration rates or speed increases during the response, but these are secondary to the cognitive and mechanical reaction time of the pilot. Each of these plays a role in determining the aircraft's necessary performance metrics and safety margins.