A method is described for optimized energy management of an aircraft upon a flight along a trajectory. The method allows the aircraft to join a given point of the trajectory in a given energy state, with a given position of the slats and flaps, and with a given position of the landing gear. The method includes determining current parameter values of the aircraft. The method also includes determining optimized command orders based on the current parameter values by performing a sequence of operations in an iterative way. The method further includes applying the optimized command orders to an automatic slats and flaps command device and an automatic landing gear command device for automatic control of the slats and flaps and the landing gear, respectively.