A flying apparatus includes a main structure and a rotative wing surface, the rotation of the wing surface allowing stabilizing the apparatus (100). A fuselage hangs from the wing surface around a hanging point, allowing the wing surface and the fuselage be moveable independently with respect to each other and the wing surface is configured as a disc to manoeuvre the apparatus and including one or more elements acting as security and secondary command and control surfaces, orienting the apparatus in desired directions. The main structure and wing surface can overwrap at least partially the the fuselage in order to improve the aerodynamic performance. The airframe or fuselage and the wing surface are rotatable around any of three rotational axes independently.

A flying apparatus includes a main structure and a rotative wing surface, the rotation of the wing surface allowing stabilizing the apparatus (100). A fuselage hangs from the wing surface around a hanging point, allowing the wing surface and the fuselage be moveable independently with respect to each other and the wing surface is configured as a disc to manoeuvre the apparatus and including one or more elements acting as security and secondary command and control surfaces, orienting the apparatus in desired directions. The main structure and wing surface can overwrap at least partially the the fuselage in order to improve the aerodynamic performance. The airframe or fuselage and the wing surface are rotatable around any of three rotational axes independently.

An aircraft of a modular type including: at least one rotor suitable for providing in full or in part propulsion and/or lift for the aircraft; at least one power plant of the combustion engine type or of the electric motor type; a main gearbox, for mechanically transmitting drive torque generated by the at least one power plant to the at least one rotor; and an avionics system for assisting in piloting the aircraft. In accordance with the invention, the avionics system is configured for automatically providing the assistance in piloting the aircraft when the aircraft has a first power plant only or when the aircraft has a first power plant and a second power plant.

An aircraft of a modular type including: at least one rotor suitable for providing in full or in part propulsion and/or lift for the aircraft; at least one power plant of the combustion engine type or of the electric motor type; a main gearbox, for mechanically transmitting drive torque generated by the at least one power plant to the at least one rotor; and an avionics system for assisting in piloting the aircraft. In accordance with the invention, the avionics system is configured for automatically providing the assistance in piloting the aircraft when the aircraft has a first power plant only or when the aircraft has a first power plant and a second power plant.

In some examples, an aircraft gearbox comprises a plurality of gears and a hybrid lubrication system to lubricate the plurality of gears. The plurality of gears comprises a first gear and a second gear. The plurality of gears operable to rotate based on torque received from a driveshaft. The hybrid lubrication system comprises a pressurized lubrication system and a non-pressurized lubrication system. The pressurized lubrication system comprises a nozzle to spray a lubricant onto the first gear. The non-pressurized lubrication system comprises a reservoir to catch a portion of the lubricant from the pressurized lubrication system. The second gear is operable to disperse the lubricant across others of the plurality of gears based on the second gear rotating through the portion of the lubricant. The non-pressurized lubrication system further comprises a shroud configured to confine the portion of the lubricant within the non-pressurized lubrication system and to return overspray of the lubricant sprayed onto the first gear and lubricant dispersed by the second gear to the reservoir.

An epicyclic gear system includes an input sun gear configured to receive rotational input from a turbine of a turbo charger. A first set of planet gears is distributed around and meshes with the input sun gear. A carrier holds the first set of planet gears and defines a rotational axis about which the carrier rotates. A second set of planet gears is mounted to the carrier. An output sun gear is included, wherein the second set of planet gears are distributed around and mesh with the output sun. The output sun gear is configured to deliver rotational power to an internal combustion engine. The carrier is configured to selectively be driven by a variable speed drive to regulate output to the output sun over a range of input rotational speeds of the input sun gear.

An epicyclic gear system includes an input sun gear configured to receive rotational input from a turbine of a turbo charger. A first set of planet gears is distributed around and meshes with the input sun gear. A carrier holds the first set of planet gears and defines a rotational axis about which the carrier rotates. A second set of planet gears is mounted to the carrier. An output sun gear is included, wherein the second set of planet gears are distributed around and mesh with the output sun. The output sun gear is configured to deliver rotational power to an internal combustion engine. The carrier is configured to selectively be driven by a variable speed drive to regulate output to the output sun over a range of input rotational speeds of the input sun gear.

Drive system for an aircraft, including: a propeller; electric motor; transmission system for transmitting positive torque from the motor to drive the propeller and negative torque from the propeller in windmill braking state to drive the motor; interface for inputting an input; first unit for controlling torque acting on the motor; second unit for detecting rotational speed of the motor; selection unit to select an active mode from propulsion mode and recovery mode, wherein the motor generates recovery energy in the recovery mode; and management system to control energy flow in an electrical system of the aircraft, the electrical system including the motor, is controlled according to the active mode; wherein the selection unit is configured to select the active mode according to the input, rotational speed, and predefined envelope, wherein the envelope indicates a maximum positive torque and minimum negative torque that depends on the rotational speed.

Drive system for an aircraft, including: a propeller; electric motor; transmission system for transmitting positive torque from the motor to drive the propeller and negative torque from the propeller in windmill braking state to drive the motor; interface for inputting an input; first unit for controlling torque acting on the motor; second unit for detecting rotational speed of the motor; selection unit to select an active mode from propulsion mode and recovery mode, wherein the motor generates recovery energy in the recovery mode; and management system to control energy flow in an electrical system of the aircraft, the electrical system including the motor, is controlled according to the active mode; wherein the selection unit is configured to select the active mode according to the input, rotational speed, and predefined envelope, wherein the envelope indicates a maximum positive torque and minimum negative torque that depends on the rotational speed.

An easily inspected shaft assembly is provided and includes a shaft, a sleeve receptive of a portion of the shaft and an optically activatable layer including first and second sections disposed on respective exterior surfaces of the shaft and the sleeve, respectively, such that the first and second sections move relative to one another as the shaft and the sleeve move relative to one another.