US Patent 11767106 Electric vertical take off and landing vehicle

An aircraft includes an airframe, and a coaxial main rotor assembly including a static mast and an upper rotor assembly and a lower rotor assembly rotatable about a main rotor axis defined by the static mast. The upper rotor assembly and the lower rotor assembly are independently rotatable about the static mast. A propulsion system includes at least one propulsion source for directly driving at least one of the upper rotor assembly and the lower rotor assembly and a flight control system is operably coupled to the propulsion system. The flight control system is operable to independently control a rotational speed of the upper rotor assembly and the lower rotor assembly relative to the static mast.