Which condition results in a failure to provide thrust when the thrust levers are at the FLX/MCT detent?

A failure to provide thrust when the thrust levers are at the FLX/MCT detent can occur if the flex temperature is not entered in the takeoff performance page. The FLX (Flex moderate) or MCT (Maximum Continuous Thrust) detent is specifically designed for thrust management in optimized performance scenarios. For the engines to develop the intended thrust at these settings, proper data entry regarding the flex temperature is essential. The flex temperature helps determine the maximum allowable thrust limit for takeoff under specific conditions, and if it is not set appropriately, the engine control system may not be able to configure the thrust correctly, leading to a failure to achieve the expected thrust output.

This understanding highlights how critical accurate input in the aircraft's performance data systems is for safe and effective operation.