An aircraft includes a plurality of takeoff and landing rotors each generating a first airflow below the takeoff and landing rotor, and a cruise rotor generating a second airflow behind the cruise rotor, the plurality of takeoff and landing rotors including a rear rotor disposed behind the cruise rotor. The aircraft further includes an airflow deflection mechanism capable of changing a direction of the second airflow, and a controller for controlling the airflow deflection mechanism to suppress interference between the first airflow generated by the rear rotor and the second airflow.

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 method of operating an electrically powered rotorcraft of the type having a fuselage and a set of N rotors driven by a set of electric motors and coupled to the fuselage, N?4, under a failure condition preventing ordinary operation of the rotorcraft. The method includes entering a failsafe mode of operation wherein autorotation of at least four of the rotors is enabled. The method also includes using electrical braking associated with a selected group of the rotors to control pitch, roll and yaw of the rotorcraft.

A method of operating an electrically powered rotorcraft of the type having a fuselage and a set of N rotors driven by a set of electric motors and coupled to the fuselage, N?4, under a failure condition preventing ordinary operation of the rotorcraft. The method includes entering a failsafe mode of operation wherein autorotation of at least four of the rotors is enabled. The method also includes using electrical braking associated with a selected group of the rotors to control pitch, roll and yaw of the rotorcraft.

An autopilot actuator includes first and second motors each including a rotatable motor output shaft such that either one or both of the motors can drive an actuator output shaft. An autopilot main unit enclosure is removably mounted to the helicopter proximate to a cyclic control and commonly houses autopilot actuators as well as main autopilot electronics. A cyclic vibration isolator is removably supported by an actuator shaft for co-rotation and coupled to the cyclic control to attenuate a cyclic vibration frequency at the actuator shaft while output rotations of the actuator shaft below a resonant frequency are coupled to the cyclic control. A force limited link includes first and second ends and a variable length between. The force limited link having a relaxed length when less than an unseating force is applied and the variable length changes when an applied force exceeds the unseating force to permit pilot override.

An autopilot actuator includes first and second motors each including a rotatable motor output shaft such that either one or both of the motors can drive an actuator output shaft. An autopilot main unit enclosure is removably mounted to the helicopter proximate to a cyclic control and commonly houses autopilot actuators as well as main autopilot electronics. A cyclic vibration isolator is removably supported by an actuator shaft for co-rotation and coupled to the cyclic control to attenuate a cyclic vibration frequency at the actuator shaft while output rotations of the actuator shaft below a resonant frequency are coupled to the cyclic control. A force limited link includes first and second ends and a variable length between. The force limited link having a relaxed length when less than an unseating force is applied and the variable length changes when an applied force exceeds the unseating force to permit pilot override.

A rotor system includes a rotor hub, a plurality of rotor blades supported by the rotor hub, and a fairing mounted to the rotor hub. The fairing includes an external surface exposed to an external airflow and an internal surface defining an interior portion. One or more heat generating components are arranged in the interior portion. A cooling system is arranged in the interior portion. The cooling system includes a first heat exchanger thermally connected to each of the one or more heat generating components, a second heat exchanger mounted to the fairing, and at least one fluid conduit extending therebetween so as to remove heat generated by each of the one or more heat generating components.

A pneumatic actuated trim tab system adapted to be mounted on a rotor blade to pneumatically alter aerodynamic properties of the rotor blade. The system includes an inflatable diaphragm adapted to be mounted on one or each side of the rotor blade; a deformable plate attached to each of the inflatable diaphragm, such that inflation and deflation of the inflatable diaphragm causes movement of each of the plates; a valving system connected to each inflatable diaphragm to allow input of a fluid into each inflatable diaphragm and allow release of a fluid out of each inflatable diaphragm; and a controller for controlling fluid pressure into and out of each inflatable diaphragm using the valving system.

A pneumatic actuated trim tab system adapted to be mounted on a rotor blade to pneumatically alter aerodynamic properties of the rotor blade. The system includes an inflatable diaphragm adapted to be mounted on one or each side of the rotor blade; a deformable plate attached to each of the inflatable diaphragm, such that inflation and deflation of the inflatable diaphragm causes movement of each of the plates; a valving system connected to each inflatable diaphragm to allow input of a fluid into each inflatable diaphragm and allow release of a fluid out of each inflatable diaphragm; and a controller for controlling fluid pressure into and out of each inflatable diaphragm using the valving system.

An aircraft tail rotor system includes a rotating pitch change shaft, a translating element, and a pitch change bearing assembly including a first bearing and a second bearing. The pitch change bearing assembly is operable to transmit movement of the translating element to the rotating pitch change shaft via the first bearing or the second bearing. A failure section is formed at an interface between the first bearing and the translating element. When the failure section decouples the first bearing from the translating element such that the first bearing does not transmit movement of the translating element to the rotating pitch change shaft, the second bearing transmits movement of the translating element to the rotating pitch change shaft.