US Patent 11993375 Method and apparatus for lifting a payload

A method and apparatus for lifting a payload wherein a first mechanical-rotor is driven by an internal combustion engine. A portion of the mechanical work developed by the internal combustion engine is used to generate electrical power, which is either stored in a battery or used to power an electric motor that drives a second rotor. Thrust developed by the mechanical and electrical rotors is directed downward to provide lift for the payload.