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.

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 discloses a rotor control system where rapid changes in rotor torque are transferred into moment forces acting about the blade pitch axis of a rotor blade in a thrust-generating rotor, to ultimately control the movements of a rotary wing aircraft. The moment forces acting on the rotor blade are transferred through a carefully adjusted damping member in order to allow rapid changes in rotor torque to create cyclic changes in blade pitch angle, while slow or permanent changes are cancelled out and affects the rotational speed and the thrust generated by the rotor, without permanently affecting the blade pitch angle of individual rotor blades.

The present invention discloses a rotor control system where rapid changes in rotor torque are transferred into moment forces acting about the blade pitch axis of a rotor blade in a thrust-generating rotor, to ultimately control the movements of a rotary wing aircraft. The moment forces acting on the rotor blade are transferred through a carefully adjusted damping member in order to allow rapid changes in rotor torque to create cyclic changes in blade pitch angle, while slow or permanent changes are cancelled out and affects the rotational speed and the thrust generated by the rotor, without permanently affecting the blade pitch angle of individual rotor blades.

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.

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.