Method for managing power demand for the operation of an unmanned aircraft provided with an internal combustion engine

Method for managing a power demand P D to ensure the operation of an unmanned aircraft, this aircraft comprising an internal combustion engine (12) providing a maximum main power P M capable of varying, in which a turbine is supplied with exhaust gases and drives an electrical generator, the electrical energy being either stored or used to assist the internal combustion engine. This management method is particularly adapted to an unmanned rotorcraft, by enabling the storage of electrical energy at least equal to recovery energy of the aircraft in the event of failure of the internal combustion engine, this recovery energy enabling the control of autorotation of the aircraft and its landing.