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 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.

The present invention relates to A device for supplying hydraulic power, the device comprising two hydraulic circuits jointly feeding multi-cylinder hydraulic power transmission means in which each cylinder is connected to a single one of the hydraulic circuits independently of the others. Each hydraulic circuit includes a hydraulic pressure and flow rate generator and a pressure control module controlling said hydraulic pressure and flow rate generator so as to regulate the pressure of said fluid flowing in said hydraulic circuit as a function of said pressure of said fluid flowing in each hydraulic circuit and possibly as a function of one or more parameters external to said device.

The present invention relates to A device for supplying hydraulic power, the device comprising two hydraulic circuits jointly feeding multi-cylinder hydraulic power transmission means in which each cylinder is connected to a single one of the hydraulic circuits independently of the others. Each hydraulic circuit includes a hydraulic pressure and flow rate generator and a pressure control module controlling said hydraulic pressure and flow rate generator so as to regulate the pressure of said fluid flowing in said hydraulic circuit as a function of said pressure of said fluid flowing in each hydraulic circuit and possibly as a function of one or more parameters external to said device.

A Stability and Control Augmentation System (“SCAS”) module comprising one or more SCAS actuators, the or each SCAS actuator comprising a mechanical component that translates rotational motion to linear motion along a first axis of said SCAS; one or more electric motors for driving linear movement of the mechanical component in response to a command signal; and one or more angular transducers to detect the position of the SCAS actuator along the first axis.

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 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.

The application discloses a coaxial helicopter, the cyclic pitch-changing mechanism simultaneously adjusts the pitches of the upper and the lower rotor systems, to make uniformity cyclic pitch-changing adjustment of the upper and lower rotors, and make independent collective pitch adjustment of the upper rotor system; the differential pitch-changing mechanism and the cyclic pitch-changing mechanism jointly act on the lower rotor system, to perform differential collective pitch adjustment of the upper and lower rotor systems. The synchronous rotating mechanism drives the swashplate members to synchronously rotate along with the drive shaft. The application achieves a simpler hybrid pitch-changing control system of the coaxial rotor pitch, a plurality of flight operations of the coaxial aircraft are performed synchronously, and a plurality of flight control modes, such as semi-differential and full-differential in a variable speed or a fixed speed mode, are supported, and thus the present application has wider application space.

The application discloses a coaxial helicopter, the cyclic pitch-changing mechanism simultaneously adjusts the pitches of the upper and the lower rotor systems, to make uniformity cyclic pitch-changing adjustment of the upper and lower rotors, and make independent collective pitch adjustment of the upper rotor system; the differential pitch-changing mechanism and the cyclic pitch-changing mechanism jointly act on the lower rotor system, to perform differential collective pitch adjustment of the upper and lower rotor systems. The synchronous rotating mechanism drives the swashplate members to synchronously rotate along with the drive shaft. The application achieves a simpler hybrid pitch-changing control system of the coaxial rotor pitch, a plurality of flight operations of the coaxial aircraft are performed synchronously, and a plurality of flight control modes, such as semi-differential and full-differential in a variable speed or a fixed speed mode, are supported, and thus the present application has wider application space.

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.