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.

A convertiplane is described that has a fuselage with a first axis, a pair of half-wings, and a pair of rotors arranged on mutually opposite ends of the half-wings. The rotor comprises a mast hinged on a second axis and a plurality of blades hinged on the mast. The mast of the rotor can be tilted with the second axis about a third axis transversal to the second axis and with respect to the fuselage to transform the convertiplane between a helicopter mode and an aeroplane mode; the second axis is transversal to the first axis in the helicopter mode and is parallel to the first axis in the aeroplane mode. The rotor disc can be tilted about a fourth axis. The rotor comprises control means for controlling the cyclic pitch and collective pitch of the blades comprising: a first actuator controllable to vary the collective pitch, a second actuator controllable to vary the tilt of the rotor disc about the fourth axis and a rod movable to alter the tilt of the corresponding rotor disc about a fifth axis according to the mode of the convertiplane.

A convertiplane is described that has a fuselage with a first axis, a pair of half-wings, and a pair of rotors arranged on mutually opposite ends of the half-wings. The rotor comprises a mast hinged on a second axis and a plurality of blades hinged on the mast. The mast of the rotor can be tilted with the second axis about a third axis transversal to the second axis and with respect to the fuselage to transform the convertiplane between a helicopter mode and an aeroplane mode; the second axis is transversal to the first axis in the helicopter mode and is parallel to the first axis in the aeroplane mode. The rotor disc can be tilted about a fourth axis. The rotor comprises control means for controlling the cyclic pitch and collective pitch of the blades comprising: a first actuator controllable to vary the collective pitch, a second actuator controllable to vary the tilt of the rotor disc about the fourth axis and a rod movable to alter the tilt of the corresponding rotor disc about a fifth axis according to the mode of the convertiplane.

A method of controlling at least a first pitch of a first propeller and a second pitch of a second propeller of a hybrid helicopter, the hybrid helicopter having a thrust control and a yaw control that are configured to generate orders for modifying respectively a mean pitch component and a differential pitch component of the first pitch and of the second pitch, the hybrid helicopter having a collective pitch control for modifying a collective pitch component of main blades of the lift rotor. The method includes a step of: keeping with the control system the first pitch and the second pitch within a control domain that varies as a function of information relating to the collective pitch component.

A method of controlling at least a first pitch of a first propeller and a second pitch of a second propeller of a hybrid helicopter, the hybrid helicopter having a thrust control and a yaw control that are configured to generate orders for modifying respectively a mean pitch component and a differential pitch component of the first pitch and of the second pitch, the hybrid helicopter having a collective pitch control for modifying a collective pitch component of main blades of the lift rotor. The method includes a step of: keeping with the control system the first pitch and the second pitch within a control domain that varies as a function of information relating to the collective pitch component.

One embodiment is an electric drive system for an aircraft including a motor, a gear box associated with the motor, and a cooling fan for drawing air into the unit across an electronic component to cool the electronic component and for expelling air into an oil cooler for cooling oil contained therein. The electric drive system further includes an oil distribution system for distributing oil cooled by the oil cooler to at least one motor and at least one gearbox, the distributed oil being used to cool the motor and the gearbox, a reservoir for collecting the distributed oil after it has been used to cool the motor and the gearbox, and at least one structural element for retaining the motor, gearbox, the cooling fan, the oil distribution system, and the reservoir together as a unit.

One embodiment is an electric drive system for an aircraft including a motor, a gear box associated with the motor, and a cooling fan for drawing air into the unit across an electronic component to cool the electronic component and for expelling air into an oil cooler for cooling oil contained therein. The electric drive system further includes an oil distribution system for distributing oil cooled by the oil cooler to at least one motor and at least one gearbox, the distributed oil being used to cool the motor and the gearbox, a reservoir for collecting the distributed oil after it has been used to cool the motor and the gearbox, and at least one structural element for retaining the motor, gearbox, the cooling fan, the oil distribution system, and the reservoir together as a unit.

An unmanned aerial vehicle includes a propulsion system having at least one propulsion module comprised of at least one propeller and at least two motors/engines, one or more of the motors/engines providing mechanical energy to drive the propeller, wherein the difference between the angular velocities of the motors/engines provides energy input to a mechanical or magneto-mechanical linkage system to change the blade pitch angle of the propeller, in cyclic and/or collective manner.

An unmanned aerial vehicle includes a propulsion system having at least one propulsion module comprised of at least one propeller and at least two motors/engines, one or more of the motors/engines providing mechanical energy to drive the propeller, wherein the difference between the angular velocities of the motors/engines provides energy input to a mechanical or magneto-mechanical linkage system to change the blade pitch angle of the propeller, in cyclic and/or collective manner.