A hybrid propulsion engine for a rotorcraft includes a core turboshaft engine having a gas path and an output shaft that provides torque to a main rotor. A fan module is disposed relative to the core turboshaft engine and is coupled to the output shaft. The fan module has a bypass air path that is independent of the gas path. A thrust nozzle is configured to mix exhaust gases from the core turboshaft engine with bypass air from the fan module and to discharge the mixture to provide propulsive thrust. In a turboshaft configuration, the fan module is closed to prevent the flow of bypass air therethrough such that the thrust nozzle does not provide propulsive thrust. In a turboshaft and turbofan configuration, the fan module is open allowing the flow of bypass air therethrough such that the thrust nozzle provides propulsive thrust, thereby supplying propulsion compounding for the rotorcraft.

A method for the flying of a vertical take-off and landing aircraft which uses fixed rotors for both VTOL and forward flight operations. The rotors form a synthetic wing and are positioned to achieve a high span efficiency. The rotors are positioned to even out the lift across the span of the synthetic wing. The synthetic wing may also have narrow front and rear airfoils which may provide structural support as well as providing lift during forward flight, or may have a single center wing. The wing rotors are tilted forward and provide some forward propulsion during horizontal flight.

A multi-rotor aircraft includes a fuselage, a propulsion engine coupled to the fuselage that generates thnist to propel the aircraft along a first vector during forward flight, and rotors coupled to the fuselage, each rotor comprising blades, each rotor coupled to a motor, and each motor configured to supply power to and draw power from the coupled rotor. The aircraft includes a flight control system configured to control the motors coupled to the rotors in a power managed regime in which a net electrical power, consisting of a sum of the power being supplied to or drawn from each rotor by its motor, is maintained within a range determined by a feedback control system of the flight control system. The flight control system can also be leveraged to adjust rotor control inputs to modify at least one of thrust, roll, pitch, or yaw of the multi-rotor aircraft.

A compound rotor aircraft, comprises a fuselage, a lifting rotor, wings and thrust propellers, wherein the fuselage has a cabin for driving; the lifting rotor is configured to drive the fuselage to move in the vertical direction; a plurality of wings are provided and arranged symmetrically on the two sides of the fuselage; a plurality of thrust propellers are provided and arranged on the plurality of wings respectively, and are configured to provide horizontal thrust force to the fuselage to drive the aircraft to move in the horizontal direction. The aircraft has various flight modes such as helicopter mode, compound helicopter mode, gyrocopter mode, compound gyrocopter mode and fixed-wing cruising mode, and can be transited among the modes. In the case of power failure of the lifting rotor, the aircraft can be transited into a gyrocopter state and continue the flight safely.

A drive system for a rotorcraft includes at least one engine, the engine including a compressor section, and a turbine section positioned rearward from the compressor section. A main rotor input shaft extends from a rotor power turbine of the turbine section and is connectable to a main rotor assembly of the rotorcraft to transfer rotational energy from the rotor power turbine to the main rotor assembly. An auxiliary input shaft extends from an auxiliary power turbine of the turbine section and is connectible to an auxiliary rotor assembly of the rotorcraft to transfer rotational energy from the auxiliary power turbine to the auxiliary rotor assembly.

A flight control system having a plurality of dual mode operator control inputs is disclosed and includes a plurality of active parallel actuators, one or more processors, and memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive a signal indicating an airspeed of the compound aircraft and select between rotary and fixed wing modes of operation based on the airspeed. In response to selecting a mode of operation, the flight control system sends either a rotary or a fixed wing force feel profile to the plurality of active parallel actuators, where the force feel profile defines the respective detent force gradient, where the fixed wing detent force gradient is at least about two times greater than a rotary wing detent force gradient.

A vertical take-off and landing aircraft which uses fixed rotors for both VTOL and forward flight operations. The rotors form a synthetic wing and are positioned to achieve a high span efficiency. The rotors are positioned to even out the lift across the span of the synthetic wing. The synthetic wing may also have narrow front and rear airfoils which may provide structural support as well as providing lift during forward flight. The wing rotors are tilted forward and provide some forward propulsion during horizontal flight.

Systems and methods include providing an aircraft with a fuselage, a tail boom or empennage extending from the fuselage, a main rotor, a tail rotor, and at least one counter torque device. The counter torque device provides counter torque to the fuselage to prevent rotation of fuselage when the main rotor is operated, particularly in right sideward flight (RSF) for conventional helicopters with a counter-clockwise rotating (when viewed from above the helicopter) main rotor.

A method of protecting a margin for controlling the yaw attitude of a hybrid helicopter that includes a lift rotor as well as at least one first propeller and at least one second propeller. A thrust control is configured to generate at least a first order issued to increase a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller. After a first order has been issued, the method includes an inhibition step for having a control computer inhibit the first order when a yaw attitude control margin, with regard to an envelope delimiting a flight control domain, is and/or will be less than or equal to a threshold.

A method and to a system of reducing the noise generated in-flight by a vortex wake caused by each first blade of a main rotor of a hybrid helicopter. The hybrid helicopter includes a main rotor, at least two wings and at least one propeller. The method enables a stabilized flight phase on the level or with a non-zero aerodynamic slope to be implemented by determining a first value of the pitch of the second blades of each propeller and an angle of incidence of the main rotor as function of the flight conditions, then by applying the first pitch value to each propeller and by applying the angle of incidence to the main rotor so as to direct the vortex wake to limit the noisy interactions between the vortex wake and the other first blades and/or the second blades.