Are thrust reversers considered in the stopping distance calculation before reaching V1?

Thrust reversers are not considered in the stopping distance calculation before reaching V1 because V1 is defined as the maximum speed at which a pilot can make a decision to abort a takeoff and still come to a stop within the available runway length. The calculation for V1 is based solely on the aircraft's braking capabilities without the assistance of thrust reversers.

This approach ensures that the stopping distance is calculated conservatively, taking into account only the primary braking system to guarantee safety under various conditions. By excluding thrust reversers from this calculation, pilots can maintain confidence that they can stop the aircraft in an emergency using just the brakes, which is critical for safety during takeoff operations.

In practical terms, while thrust reversers do provide additional stopping power after V1, their contribution is not factored into the decision-making parameters leading up to that point. Thus, relying solely on brake power for the calculation of V1 reflects standard operating procedures designed to enhance safety.