A multi-rotor aircraft includes a fuselage, a propulsion engine coupled to the fuselage that generates thrust to propel the aircraft along a first vector during forward flight, and rotors coupled to the fuselage, each rotor comprising blades, each rotor coupled to a motor, and each motor configured to supply power to and draw power from the coupled rotor. The aircraft includes a flight control system configured to control the motors coupled to the rotors in a power managed regime in which a net electrical power, consisting of a sum of the power being supplied to or drawn from each rotor by its motor, is maintained within a range determined by a feedback control system of the flight control system. The flight control system can also be leveraged to adjust rotor control inputs to modify at least one of thrust, roll, pitch, or yaw of the multi-rotor aircraft.

An autogyro includes a frame and a rotor hub coupled to the frame. The autogyro also includes a connector coupled to the rotor hub and configured to couple the rotor hub to a ground-based pre-rotator device to rotate the rotor hub during a vertical take-off operation. The autogyro further includes a plurality of rotor blades coupled to the rotor hub, each rotor blade configured such that rotation of the rotor hub, during the vertical take-off operation, results in twisting the rotor blade from a first blade pitch distribution to a second blade pitch distribution.

The invention relates to a drive system for a vehicle, comprising at least one asymmetrical rotor (18), which has at least one rotor blade (20) extending radially from a rotor axle, and a counterweight (22) which is opposite the rotor axle, the system further comprising a control device for the electric motor (24), which connects the electric motor (24) to a battery for the power supply thereof, and is configured and designed, during a revolution cycle, which includes 1-3 revolutions of the rigid rotor blade (20), to bring about at least one acceleration phase, in which the electric motor (24) can be accelerated to accelerate the rotor (18), and at least one braking phase, in which the electric motor (24) can be braked, the control device being designed, during at least part of the braking phase, to connect the electric motor (24) to at least one battery element (28) in generator mode.

Off-board gyrocopter take-off systems and associated methods are disclosed. A representative method includes restraining a gyrocopter from vertical and lateral movement, pre-rotating a fixed-pitch lift rotor of the gyrocopter via a power source located off the gyrocopter, and releasing the gyrocopter for vertical movement to allow the gyrocopter to lift under a force provided by the lift rotor. Optionally, the method can further include interrupting or reducing power from the power source to the gyrocopter as a way to release the gyrocopter for vertical movement.

A helicopter rotor transmission in which the average lubricant monitoring and replenishment intervals are to be significantly increased. The helicopter rotor transmission has a central cavity, in which runs a bearing mast that is fixed in a locationally and rotationally manner, which is held passing through the gear housing at least partially in the direction of the central axis. An internally toothed gear ring of a rotatable rotor mast can be rotated about the central axis, with fixed rotation of the planetary gears about their planetary gear axes, such that the rotor mast can be set in rotation by means of a gear ring driver attached to the gear ring.

A rotorcraft capable of a hover mode and a forward cruise mode including a fuselage, a first electric propulsion system, a second electric propulsion system, and an electric power control unit to control power to the first and second electric propulsion systems in the hover and forward cruise modes. The first electric propulsion system is a tip jet cold flow system that imparts rotation on a pair of rotor blades disposed above a top surface of the fuselage, and a first electric motor configured to drive the tip jet cold flow system. The second electric propulsion system includes a propeller disposed in the rear of the fuselage and a second electric motor configured to drive the propeller.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.

Aircraft and methods of operating the aircraft to provide for increased descent angles. The aircraft includes a fuselage having fixed wings, a horizontal thrust source coupled to the fuselage and configured to selectively generate and supply horizontal thrust to the aircraft, a vertical thrust source coupled to the fuselage and configured to selectively generate and supply vertical thrust to the aircraft, the vertical thrust source including a vertical thrust rotor that is configured to selectively operate in a locked mode, in which the vertical thrust rotor cannot rotate freely in response to contact of airflow therewith, and an unlocked mode, in which the vertical thrust rotor can rotate freely in response to contact of airflow therewith, and a controller configured to selectively supply a command to the vertical thrust source that causes the vertical thrust rotor to operate in the unlocked mode.

Off-board gyrocopter take-off systems and associated methods are disclosed. A representative method includes restraining a gyrocopter from vertical and lateral movement, pre-rotating a fixed-pitch lift rotor of the gyrocopter via a power source located off the gyrocopter, and releasing the gyrocopter for vertical movement to allow the gyrocopter to lift under a force provided by the lift rotor. Optionally, the method can further include interrupting or reducing power from the power source to the gyrocopter as a way to release the gyrocopter for vertical movement.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.