A first power source, a second power source, and a power controller are provided, where a vehicle that includes the first power source, the second power source, and the power controller is capable of flying in a transitional mode between a hovering mode and a forward flight mode. The power controller selects one or more of the first power source and the second power source to power a rotor included in the vehicle during the transitional mode.

A tiltrotor has a range of motion between a forward flight position and a hovering position, where a pylon and the tiltrotor are coupled via a telescoping actuator, a rigid bottom bar, and a fixed hinge that is attached between the rigid bottom bar and the tiltrotor. The tiltrotor moves from the forward flight position to the hovering position includes extending the telescoping actuator so that the tilt rotor rotates about the fixed hinge.

An aircraft is provided including an airframe, an extending tail, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe. A cockpit in the airframe, the cockpit including two seats and a single collective control input positioned between the two seats.

A fully compounding rotorcraft includes a fuselage having first and second wings extending therefrom and configured to provide lift compounding responsive to forward airspeed. A twin boom includes first and second tail boom members that extend aftward from the first and second wings. An empennage is coupled between the aft ends of the tail boom members. An anti-torque system includes a tail rotor that is rotatably coupled to the empennage. An engine is disposed within the fuselage and is configured to provide torque to a main rotor assembly via an output shaft and a main rotor gearbox. An auxiliary propulsive system is coupled to the fuselage and is configured to generate a propulsive thrust to offload at least a portion of a thrust requirement from the main rotor during forward flight, thereby providing propulsion compounding to increase the forward airspeed of the rotorcraft.

According to an aspect, a clevis assembly includes a shackle having two ends, each end respectively including an aperture, a structure connecting the apertures and housing a bearing, and a shearing device that includes a frangible point and is in operable communication with the bearing, where the shearing device is housed in a hollow portion of the structure.

An exemplary tail rotor includes a first blade assembly configured to rotate in a first direction about an axis of rotation and a second blade assembly configured to rotate in a second direction about the axis of rotation.

An aircraft is provided and includes an airframe, an extending tail, a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly, a translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe, at least one sensor and at least one inertial measurement unit (IMU) to sense current flight conditions of the aircraft, an interface to execute controls of a main rotor assembly in accordance with control commands and at least one flight control computer (FCC) to issue the control commands. The at least one FCC includes a central processing unit (CPU) and a memory having logic and executable instructions stored thereon, which, when executed, cause the CPU to issue the control commands based on the current flight conditions and a result of an execution of the logic for the current flight conditions.

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.

An anti-torque assembly for a helicopter includes a plurality of fans pivotably mountable to a tail boom. The fans have fan blades rotatable about a fan axis. One or more of the fans is pivotable relative to the tail boom to a first configuration. The fan axes in the first configuration have an upright orientation and the fans are operable to one or both of pitch and roll the helicopter. Different fans are operable to generate thrust to provide anti-torque to the helicopter. A method of providing anti-torque and method of changing an attitude of a helicopter are also provided.

An electric propulsion system includes a static mast defining an axis of rotation and a stationary rotor hub assembly coupled to the static mast. A rotating system is rotatably mounted to the stationary rotor hub assembly. The electric propulsion system additionally includes an electric motor including a stator assembly associated with the rotor hub assembly and a rotor assembly associated with the rotating system.