When can the flex thrust procedure be used on wet runways?

The flex thrust procedure can be used on wet runways specifically when there is performance data that indicates it is safe to do so. Wet runway conditions can significantly impact the aircraft's stopping distance and performance characteristics. Utilizing performance data allows pilots to make informed decisions based on actual wet runway performance metrics, which detail how much thrust reduction can be safely utilized without compromising safety during takeoff.

The performance data takes into account the specifics of the runway surface, weather conditions, and aircraft weight, ensuring that pilots have the necessary information to evaluate whether deploying flex thrust is a safe option. This procedural alignment minimizes the chances of runway overruns or insufficient takeoff performance during the critical phases of flight.

The other choices lack the necessary emphasis on performance data, which serves as a critical threshold for safety in wet runway operations.