Methods and systems are provided for guiding or otherwise assisting energy management of an aircraft en route to a runway. A method to optimize managing energy of an aircraft in a landing trajectory when deploying landing gear, the system including evaluating an energy state for the aircraft for a set of flight trajectories including a lateral and a vertical trajectory for a flight path in an approach phase to a runway; identifying at least one energy state for the aircraft based on a set of formulated computations based on an altitude and speed of a vertical aircraft profile on the flight path in the approach phase; and assessing in an envelope region a landing gear extension to manage the excess energy at a prediction location in the flight path; and deploy the landing gear responsive to an assessed change in the aircraft energy state in route to the runway.