A system and method to improve efficiency in aircraft maneuvers meant to accommodate time-related constraints in air traffic. Information related to flight performance and atmospheric conditions is gathered onboard an aircraft, then transmitted to an air traffic control center. In the event of a delay or any other event which necessitates an alteration in an aircraft trajectory, the data is sent to a decision support tool to compute and provide alternative trajectories, preferably including operator-preferred trajectories, within air traffic constraints. Air traffic controllers can then offer an alternative trajectory to an aircraft that is more efficient, cost effective, and/or preferable to the aircraft operator.