A rotorcraft includes a substantially rigid structural body. The structural body has an internal cavity and an aperture extending entirely through the structural body. The rotorcraft further includes at least one of a tail boom and a fuselage. The rotorcraft further includes a propulsion device disposed at least partially within the internal cavity and at least partially within the aperture. The propulsion device is carried by the structural body so that forces are transferred from the propulsion device to at least one of the tail boom and the fuselage via the structural body.

A variable speed transmission is disclosed, with a transmission apparatus which includes a planetary gear set having a ring gear and a sun gear. The variable speed transmission further includes a primary engine for powering the sun gear, a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device.

A system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprises: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

An exemplary anti-torque system for a helicopter includes two or more electric fans rotatably mounted on a tail boom, the two or more electric fans rotatable about a longitudinal axis of the tail boom.

A helicopter includes annular electric motors surrounding a fuselage. Each annular electric motor includes an annular stator and an annular rotor. Rotor blades extend radially outwardly from each annular rotor. In an embodiment with two electric motors, one rotor rotates in one direction and the other rotor rotates in the opposite direction. A swash device with a grooved outer cylindrical surface engages the free end of a crank arm of each rotor blade to provide collective and cyclic pitch control. Actuators, which may be electromechanical or hydraulic, control positioning and movement of the swash device. Batteries, an electric generator and/or a hydrogen fuel cell may supply electric power.

The present invention includes an a plurality of first variable speed motors mounted on a tail boom of the helicopter; one or more fixed pitch blades attached to each of the plurality of first variable speed motors; and wherein a speed of one or more of the plurality of first variable speed motors is varied to provide an anti-torque thrust.

A vehicle includes a tilt rotor that is aft of a wing and that is attached to the wing via a pylon. The tilt rotor has an adjustable maximum downward angle from horizontal that is less than or equal to 60° and that is set via a setting associated with a flight computer. The vehicle takes off and lands using at least some lift from the wing and from the tilt rotor. In response to a change to the adjustable maximum downward angle, via the setting associated with the flight computer, which produces a new maximum downward angle: the flight computer updates an actuator authority database associated with the flight computer to reflect the new maximum downward angle. Using the updated actuator authority database that reflects the new maximum downward angle, the flight computer generates a rotor control signal for the tilt rotor.

A system includes an inboard tiltrotor subsystem and an outboard tiltrotor subsystem. The inboard tiltrotor subsystem includes an inboard pylon, an inboard tiltrotor, and a single and non-redundant drivetrain. The outboard tiltrotor subsystem includes an outboard pylon that is coupled to a wing and an outboard tiltrotor. The outboard tiltrotor has a range of motion and is coupled to the wing via the outboard pylon, such that the outboard tiltrotor is aft of the wing. The outboard tiltrotor subsystem further includes a redundant drivetrain (which has a plurality of motors and a plurality of motor controllers) that drives one or more blades and the one or more blades.

A pylon is coupled to a wing. A tiltrotor, having a range of motion, is coupled to the wing via the pylon, such that the tiltrotor is aft of the wing. The tiltrotor includes a redundant drivetrain, including a plurality of motors and a plurality of motor controllers, that drives one or more blades included in the tiltrotor.

A short takeoff and landing (STOL) vehicle which comprises a tail having a surface and a fuselage having a surface, where the tail and the fuselage have a continuity of surfaces where the surface of the tail is directly coupled to the surface of the fuselage. The vehicle further includes a forward-swept wing having a trailing edge and a rotor that is attached to the trailing edge of the forward-swept wing via a pylon, where the rotor has a maximum downward angle from horizontal that is less than or equal to 60° and the STOL vehicle takes off and lands using at least some lift from the forward-swept wing and at least some lift from the rotor.