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.

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 rotorcraft has a frame and a plurality of rotors connected to the frame. The frame has a roll axis and a pitch axis. Each of the rotors includes a rotor shaft. The rotor shaft of each of the rotors is canted with respect to at least one of the roll axis and the pitch axis. The rotor shaft of each of the rotors may be canted between 3 and 15 degrees. Each of the rotors may be a co-axial co-rotating rotor. The rotors may be oriented in opposing pairs across the frame. Both rotors in each opposing pair rotate in the same direction. The rotorcraft may include at least two additional rotors, each having a forward cant. Each of the additional rotors may be a co-axial contra-rotating rotor.

A control circuitry includes a first filter configured to filter a gravity compensated longitudinal acceleration of an aircraft to generate a filtered gravity compensated longitudinal acceleration. The propulsor trim control circuitry also includes a second filter configured to generate a filtered speed of the aircraft based on a speed of the aircraft. The propulsor trim control circuitry includes intermediary circuitry configured to generate a filtered longitudinal control effector error based on the filtered gravity compensated longitudinal acceleration and the speed. The propulsor trim control circuitry also includes a third filter configured to generate a filtered longitudinal thrust effector command value based on a longitudinal thrust effector command value. The propulsor trim control circuitry further includes output circuitry configured to generate a predicted longitudinal thrust effector trim value for a target horizontal state based on the filtered longitudinal control effector error and the filtered longitudinal thrust effector command value.

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.

There is provided a rotorcraft, including a body, including a front portion and a tail portion; a main rotor system coupled to the front portion of the body, the main rotor system operable to provide a lifting force on the body; and an anti-torque system coupled to the tail portion of the body, the anti-torque system including a primary tail rotor system and a secondary tail rotor system; wherein the primary tail rotor system and the secondary tail rotor system are operable to provide a first anti-torque force and a second anti-torque force. In other aspects, there are methods of providing anti-torque force in a rotorcraft.

A control circuitry includes a propulsor trim prediction circuitry and an output circuitry. The propulsor trim prediction circuitry is configured to generate a predicted proprotor nacelle trim value based on an aircraft velocity and a pitch attitude deviation from a reference. The output circuitry is configured to output a proprotor nacelle command based on the predicted proprotor nacelle trim value. The proprotor nacelle command is configured to cause an adjustment in a nacelle angle of a proprotor of an aircraft.

Embodiments are directed to a rotorcraft comprising a body having a longitudinal axis, a wing coupled to the body, a single tiltrotor assembly pivotally coupled to the body, and the tiltrotor assembly configured to move between a position generally perpendicular to the longitudinal axis during a vertical flight mode and a position generally parallel to the longitudinal axis during a horizontal flight mode. The rotorcraft may further comprise an anti-torque system configured to counteract torque generated by the tiltrotor assembly during vertical flight. The rotorcraft may further comprise a center of gravity compensation system configured to manage a rotorcraft center of gravity during movement of the tiltrotor assembly between the vertical flight mode and the horizontal flight mode.

A modal tailboom flight control system for a compound helicopter is operable in a plurality of modes including a forward thrust mode and an anti-torque mode. The modal tailboom flight control system includes a tailboom, a drivetrain extending through the tailboom, an anti-torque system coupled to the drivetrain and rotatable to generate anti-torque thrust for the compound helicopter in the anti-torque mode and a pusher propeller coupled to the drivetrain and rotatable to generate forward thrust for the compound helicopter in the forward thrust mode. The pusher propeller is positioned forward of the anti-torque system.