Methods and systems are provided for assisting operation of a vehicle deviating from a desired manner of operation, such as an aircraft deviating from a planned trajectory. One method involves identifying a current aircraft altitude, identifying a current aircraft configuration, determining a recommended flight path from the current aircraft altitude for satisfying an upcoming constraint associated with a reference descent strategy based at least in part on the current aircraft configuration in response to a deviation between the current aircraft altitude a target altitude according to the reference descent strategy, and providing an output influenced by the recommended flight path. The recommended flight path includes a recommended vertical profile and a recommended speed profile, and the recommended flight path is configured to vary at least one of a kinetic energy or a potential energy of the aircraft along the recommended flight path en route to the upcoming constraint.