A helicopter autopilot system includes an inner loop for attitude hold for the flight of the helicopter including a given level of redundancy applied to the inner loop. An outer loop is configured for providing a navigation function with respect to the flight of the helicopter including a different level of redundancy than the inner loop. An actuator provides a braking force on a linkage that serves to stabilize the flight of the helicopter during a power failure. The actuator is electromechanical and receives electrical drive signals to provide automatic flight control of the helicopter without requiring a hydraulic assistance system in the helicopter. The autopilot can operate the helicopter in a failed mode of the hydraulic assistance system. A number of flight modes are described with associated sensor inputs including rate based and true attitude modes.

A differential thrust vectoring system including a first thruster rotation assembly configured to rotate a first thruster relative of an aircraft, a second thruster rotation assembly configured to rotate a second thruster of an aircraft, and an actuator. The system is configured such that actuation of the actuator causes disparate rotation about the tilt axis of the first and second thrusters.

A differential thrust vectoring system including a first thruster rotation assembly configured to rotate a first thruster relative of an aircraft, a second thruster rotation assembly configured to rotate a second thruster of an aircraft, and an actuator. The system is configured such that actuation of the actuator causes disparate rotation about the tilt axis of the first and second thrusters.

An embodiment rotorcraft includes a main rotor, one or more flight controls connected to the main rotor and operational to control flight characteristics of the main rotor by pitching a nose of the rotorcraft upward, and a flight control computer (FCC) operable to determine an attitude command and to generate an adjusted attitude command by adjusting a magnitude of the attitude command according to an above ground level (AGL) altitude of the rotorcraft. The FCC is further operable to control a flight characteristic of the rotorcraft by sending the adjusted attitude command to one or more flight controls.

An embodiment rotorcraft includes a main rotor, one or more flight controls connected to the main rotor and operational to control flight characteristics of the main rotor by pitching a nose of the rotorcraft upward, and a flight control computer (FCC) operable to determine an attitude command and to generate an adjusted attitude command by adjusting a magnitude of the attitude command according to an above ground level (AGL) altitude of the rotorcraft. The FCC is further operable to control a flight characteristic of the rotorcraft by sending the adjusted attitude command to one or more flight controls.

An autopilot system includes an actuator arrangement that receives control signals to influence the flight of the helicopter in a selected one of a plurality of different flight modes. A control stick input arrangement allows flight mode selection and control with no more than a particular one of the pilot's hands in the engaged position on the stick and without moving the hand away from the engaged position. A slaved gyro output signal is based on no more than the set of sensor outputs used by the autopilot such that an autopilot display presents autopilot flight mode information while displaying a slaved gyro output. The autopilot provides for pilot selection of one of a subset of the plurality of flight modes which is customized based on a current flight status of the helicopter. An automatic autorotation mode is provided.

An autopilot system includes an actuator arrangement that receives control signals to influence the flight of the helicopter in a selected one of a plurality of different flight modes. A control stick input arrangement allows flight mode selection and control with no more than a particular one of the pilot's hands in the engaged position on the stick and without moving the hand away from the engaged position. A slaved gyro output signal is based on no more than the set of sensor outputs used by the autopilot such that an autopilot display presents autopilot flight mode information while displaying a slaved gyro output. The autopilot provides for pilot selection of one of a subset of the plurality of flight modes which is customized based on a current flight status of the helicopter. An automatic autorotation mode is provided.

A method of tip clearance estimation for a rotor blade is provided. The method includes measuring blade deflection of the rotor blade, generating a harmonic function for the rotor blade from the measured blade deflection, predicting tip displacement of the rotor blade using the generated harmonic function and adjusting a position of the rotor blade according to the predicted tip displacement.

A method of tip clearance estimation for a rotor blade is provided. The method includes measuring blade deflection of the rotor blade, generating a harmonic function for the rotor blade from the measured blade deflection, predicting tip displacement of the rotor blade using the generated harmonic function and adjusting a position of the rotor blade according to the predicted tip displacement.

According to one embodiment, linear motor translator assembly for use in an electromagnetic actuator is provided. The linear motor translator assembly includes: a cylindrical housing having a first end, a second end opposite the first end, a flanged portion at the second end, and a blind hole initiating at the second end and extending into the cylindrical housing to a blind hole base; a tubular body located within the blind hole, the tubular body including a plurality of permanent magnets; and an end cap securely fastened to the flanged portion.