Abstract: A foldable rotor system for a rotorcraft, the foldable rotor system comprising a rotor assembly operably associated with a driveshaft, the driveshaft being operable associated with an engine, the rotor assembly comprising a rotor blade connected to a grip pin. A swashplate is operable associated with the grip pin in order selectively change a pitch of the rotor blade. A blade fold actuator is operably associated with the grip pin such that the blade fold actuator is configured to fold and unfold the rotor blade about a blade fold axis. During an airplane mode, the rotorcraft can stop and fold the rotor blades so that the rotorcraft relies upon thrust from the engine for propulsion. The rotor blades are folded in a spiral fold path so that the rotor blades remain substantially edgewise, or feathered, during the folding process. The spiral fold path minimizes the aerodynamic drag experienced by the rotor blades while being folded during flight of the rotorcraft.

Abstract: A hydraulic control valve (10) provided with at least one body (11) having a jacket (12) with a feed orifice (13). The hydraulic control valve (10) has a transfer rod (15) provided with at least one fluid transfer duct (16), at least one orifice (17) present inside the jacket (12), and a second orifice (18) arranged outside the jacket (12). The jacket (12) has a feed chamber (25) connected to said feed orifice (13) and a main fluid-return chamber (30) connected to discharge means (50) for discharging the fluid, control means (20) being secured to the jacket (12) in order to move the jacket (12) in translation relative to said transfer rod (15) so as to control the flow of fluid within said transfer rod (15).

Abstract: The present disclosure relates to an unmanned aerial vehicle (UAV) able to harvest energy from updrafts and a method of enhancing operation of an unmanned aerial vehicle. The unmanned aerial vehicle with a gliding capability comprises a generator arranged to be driven by a rotor, and a battery, wherein the unmanned aerial vehicle can operate in an energy harvesting mode in which the motion of the unmanned aerial vehicle drives the rotor to rotate, the rotor drives the generator, and the generator charges the battery. In the energy harvesting mode regenerative braking of the generator reduces the forward speed of the unmanned aerial vehicle to generate electricity and prevent the unmanned aerial vehicle from flying above a predetermined altitude.

Abstract: An aerial vehicle adapted for vertical takeoff and landing using a set of wing tip mounted thrust producing elements for takeoff and landing. An aerial vehicle which is adapted to vertical takeoff with the wings in a horizontal flight attitude then transitions to a horizontal flight path. An aerial vehicle which uses different configurations of its wing tip mounted, VTOL enabling rotors to reduce drag in all flight modes.

Abstract: System and method to construct vertical and/or short takeoff and landing (V/STOL) aerial vehicles capable of being folded into compact size, and capable of be combined with one or more such vehicles to form bigger composite aerial vehicles. Airframe of the vehicle comprises a plurality of wings on lateral or periphery of thrust generators, wherein arrangements of wings make it possible to optionally fold wings without moving thrust generators. Folding transforms such vehicles into ground vehicles which can share roads and house parking lots with conventional ground vehicles. Therefore such vehicles can be used as V/STOL flying cars. Means are provided for attaching to and detaching from one or more similarly equipped vehicles in flight or before takeoff, so that multiple vehicles can form a large composite vehicle. Compactness, combinability and V/STOL capability enable versatile applications.

Abstract: A flight control apparatus for fixed-wing aircraft includes a first port wing and first starboard wing, a first port swash plate coupled between a first port rotor and first port electric motor, the first port electric motor coupled to the first port wing, and a first starboard swash plate coupled between a first starboard rotor and first starboard electric motor, the first starboard electric motor coupled to the first starboard wing.

Abstract: A rotorcraft is disclosed. The rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a hub and at least one rotor blade having a tip jet. The rotorcraft may further include a plurality of compressors for generating compressed air and a network of conduits connecting the outlets of the plurality of compressors with every tip jet of the rotor. The rotorcraft may further include a control system preventing back flow through each outlet of the plurality of compressors.

Abstract: A hybrid helicopter includes a rotary wing, two half-wings with respective propellers, and an engine installation continuously driving the rotary wing and the propellers by meshing with a mechanical interconnection system. A piloting assistance device for the hybrid helicopter is configured to determine maximum mean pitch (?max) applicable to the propellers without exceeding the power available for the propellers. The piloting assistance device is configured to determine the maximum mean pitch (?max) as a function of the current mean pitch of the blades of the propellers as measured in real time, a maximum power that can be delivered by the engine installation, a current power being delivered by the engine installation, and a relationship determining a power gradient (GRD) as a function of pitch for the propellers.

Abstract: An aircraft (1) comprising a fuselage (2), a rotary wing (10) having two contrarotating main rotors (12) arranged in tandem above the fuselage (2), at least one propulsion member (20), and a power plant (30). Each propulsion member (20) is carried by a rear portion (3) of the fuselage. The aircraft (1) includes an interconnection system (40) providing a permanent connection between the power plant (30) and the rotary wing (10), except in the event of a failure or during training, the aircraft (1) having differential control means (50) for controlling the cyclic pitch of the blades of the main rotors (12) to control the aircraft (1) in yaw, and inhibition means (60) for inhibiting each propulsion member (20).

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Rigidity of the rotor is enhanced and play between flight controls and the rotor are eliminated by mounting swashplate actuators to a flange rigidly secured to the mast. Thermal management of the rotor is performed in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. Thermal management of a rotor may be performed by oil and air flow.

Abstract: A hybrid aircraft (1) having a fuselage (2) extending longitudinally along an anteroposterior plane of symmetry (PSYM) from the rear (4) of the aircraft (1) towards the front (3) of the aircraft (1). The aircraft (1) has a rotary wing (6) carried by the fuselage (2) of a lift surface (10) fastened to the fuselage (2) and constituted by a first half-wing (11) and a second half-wing (12). The aircraft (1) has a first propulsion unit (30) carried by the first half-wing (11) and a second propulsion unit (40) carried by the second half-wing (12). Each propulsion unit (30, 40) includes at least one tractor propeller (31, 32, 41, 42), and at least one propulsion unit has two propellers (31-32, 41-42) on the same axis, each of said propellers rotating about an axis of rotation (AX) that is offset transversely from said anteroposterior plane of symmetry (PSYM).

Abstract: A hybrid aircraft (1) having a fuselage (2) extending longitudinally along an anteroposterior plane of symmetry (PSYM) from the rear (4) of the aircraft (1) towards the front (3) of the aircraft (1). The aircraft (1) has a rotary wing (6) carried by the fuselage (2) of a lift surface (10) fastened to the fuselage (2) and constituted by a first half-wing (11) and a second half-wing (12). The aircraft (1) has a first propulsion unit (30) carried by the first half-wing (11) and a second propulsion unit (40) carried by the second half-wing (12). Each propulsion unit (30, 40) includes at least one tractor propeller (31, 32, 41, 42), and at least one propulsion unit has two propellers (31-32, 41-42) on the same axis, each of said propellers rotating about an axis of rotation (AX) that is offset transversely from said anteroposterior plane of symmetry (PSYM).

Abstract: A method of automatically triggering an emergency buoyancy system (10) for a hybrid helicopter (20) having a fuselage (21), two half-wings (23, 23?), and two propulsive propellers (24, 24?). During the method, said emergency buoyancy system (10) is primed, and then if a risk of said hybrid helicopter (20) ditching is detected, two retractable wing undercarriages (28, 28?) are deployed, each wing undercarriage (28, 28?) being fastened under a respective half-wing (23, 23?) and being provided with at least one immersion sensor (16). Finally, if the beginning of said hybrid helicopter (20) ditching is detected, at least one main inflatable bag (11, 11?) 7B suitable for being arranged under such fuselage (21) and at least one secondary inflatable bag (12, 12?) suitable for being arranged under each half-wing (23, 23?) are inflated so as to ensure that said hybrid helicopter (20) floats in stable manner.

Abstract: An aircraft (1) having a fuselage (2), a power plant (10), a rotary wing (15) having at least one main rotor (16), and a fixed wing (20) comprising two half-wings (21, 22) extending on either side of the fuselage (2). The aircraft (1) also has at least two propulsive propellers (30) on either side of the fuselage (2). Each is positioned on respective ones of the half-wings (21, 22), and an anti-torque and yaw-control tail rotor (35). A transmission system (40) connects the power plant (10) to each main rotor (16) and the tail rotor (35). The transmission system (40) connects the power plant (10) to each propeller (30) via a respective differential mechanism (50) that is controllable on request so that each propeller (30) can be driven in cruising flight and need not be driven in rotation by the power plant (10) on the ground or while hovering.

Abstract: An aircraft includes a powerplant system operable to power a main rotor system and a secondary thrust system, the secondary thrust system is selectively driven through operation of a clutch system, and a clutch system synchronization time corresponds to a response time of the powerplant system.

Abstract: An aircraft (1) having a fuselage (2), the aircraft (1) comprising a rotary wing (9) above the fuselage (2) and an extra fixed wing (10), the rotary wing (9) being above both the fuselage (2) and the fixed wing (10), said fixed wing (10) comprising at least one closed wing (20) comprising a first half-wing (21) and a second half-wing (22). Each half-wing (21, 22) is provided with a top lift portion (30) and a bottom lift portion (40), said bottom lift portion (40) of a half-wing being arranged in the wake (S) of the top lift portion (30) of that half-wing, the wake (S) being generated by a stream of air (F) coming from said rotary wing (9) and impacting against the top face (30?) of the top lift portion (30) when said aircraft (1) has a forward speed less than a predetermined threshold.

Abstract: A rotorcraft (1) having: a lift rotor (5); a wing (10) extending from a first end (11) carrying a first propulsive propeller (21) to a second end (12) carrying a second propeller (22); landing gear (30); and a tail (40). The rotorcraft (1) is provided with two fuselages (51, 52) secured to said wing (10) between said first and second propulsive propellers (21, 22) in such a manner as to present an inter-fuselage space (60) having no propeller between said fuselages (51, 52), each fuselage (51, 52) including at least one undercarriage of said landing gear (30).

Abstract: An unmanned aerial vehicle (UAV) capable of vertical and horizontal flight modes, a method for assembling a UAV, and a kit of parts for assembling a UAV. The UAV comprises a wing structure comprising elongated equal first and second wings; a support structure comprising first and second sections coupled to a middle position of the wing structure and extending in opposite directions perpendicular to the wing structure; and four propellers, each mounted to a respective one of the first and second wings, and first and second sections, for powering the UAV during both vertical and horizontal flight modes.

Abstract: A method and apparatus for managing a flight of a rotorcraft. Parameters for the flight of the rotorcraft are identified. A number of regions, above a terrain, to be avoided by the rotorcraft during the flight of the rotorcraft over the terrain are identified using the parameters for the flight of the rotorcraft. Information about the number of regions is displayed on a display device during the flight of the rotorcraft.

Abstract: A device (10) for assisted piloting of an aircraft having a rotary wing with a plurality of second blades (3?) and a propulsion unit with a plurality of first blades (2?). The device includes control means (30, 40) for delivering a movement order (O) for moving in a direction, said device (10) having a processor unit (20) for transforming said order (O) into an acceleration setpoint (C) along said direction, and then for transforming said acceleration setpoint (C) into at least one required longitudinal attitude setpoint (?*) that is transmitted to a first automatic system (26) for maintaining longitudinal attitude by controlling a longitudinal cyclic pitch of the second blades (3?), and into a first required load factor setpoint (Nx*) in a longitudinal direction that is transmitted to a second automatic system (25) for maintaining load factor by controlling the collective pitch of the first blades.

Abstract: There is described a convertiplane comprising a pair of semi-wings, a first and a second rotor which may rotate about relative first axes and tilt about relative second axes together with first axes with respect to semi-wings between a helicopter mode and an aeroplane mode; first axes are, in use, transversal to a longitudinal direction of convertiplane in helicopter mode, and are, in use, substantially parallel to longitudinal direction in aeroplane mode; first and second rotors may tilt about relative second axes independently of each other.

Abstract: A Vertical Take-off and Landing (VTOL) aerial vehicle (1, 46), e.g. a rotorcraft with long range and high cruising speed capability. The aerial vehicle (1, 46) has a torus-type fuselage (2) with radial inside a duct (5) and at least one main rotor (13, 26). A pair of lateral wings (40) are attached opposed to each other outside the fuselage (2) and at least one engine (18) drives said at least one main rotor (13, 26) and at least two propulsion means (24) fitted to each of said wings (40). The invention relates as well to a method of operating such a VTOL aerial vehicle (1, 46).

Abstract: VTOL amphibious aircraft comprising two fuselages spaced apart to enable the placement of single center wing and split ailerons, engine and rotor or fan such that they may be rotated from vertical flight to horizontal flight and back while center wing ailerons counter rotor torque. Out board wings remain fixed and the twin fuselages provide buoyant hulls to facilitate water landings. Standard aircraft components are employed such as a vertical tails and horizontal stabilizers.

Abstract: An aerial vehicle includes at least one wing, a plurality of thrust producing elements on the at least one wing, a plurality of electric motors equal to the number of thrust producing elements for individually driving each of the thrust producing elements, at least one battery for providing power to the motors, and a flight control system to control the operation of the vehicle. The aerial vehicle may include a fuselage configuration to facilitate takeoffs and landings in horizontal, vertical and transient orientations, redundant control and thrust elements to improve reliability and means of controlling the orientation stability of the vehicle in low power and multiple loss of propulsion system situations. Method of flying an aerial vehicle includes the variation of the rotational speed of the thrust producing elements to achieve active vehicle control.

Abstract: The aircraft is capable of two distinct fuel-efficient flight regimes: one is a vertical flight regime supported by two large two-bladed rotors with low disc loading located on right and left longitudinal booms. The booms extend between outboard regions of a front wing and inboard regions of a rear wing that has a larger span an area than the front wing. The other flight regime is high speed up to high subsonic Mach number with the aircraft supported by wing lift with high wing loading, and with the rotors stopped and faired with minimal local drag contiguous to the booms. The longitudinal location of the aircrafts center of gravity, aerodynamic center and the center of the rotors are in close proximity. The front wing is preferably swept back, and the rear wing is preferably of W planform.

Abstract: A method of controlling a high-speed rotary wing aircraft (1) comprising a fuselage (2), at least one main rotor (3), at least one variable-pitch propulsive propeller (4), at least two half-wings (11, 11?) positioned on either side of said fuselage (2), at least one horizontal stabilizer (20) provided with a movable surface (21, 21?), and at least one power plant driving said main rotor (3) and said propulsive propeller (4) in rotation. Said method serves to adjust the lift of said half-wings (11, 11?) and the lift of the horizontal stabilizer (20) so that said lift of said half-wings (11, 11?) represents a predetermined percentage of the total lift of said aircraft (1) and so that the power consumed by said main rotor (3) is equal to a setpoint power during a stage of stabilized flight.

Abstract: A method of controlling a high speed rotary wing aircraft (1) comprising: a fuselage (2); at least one main rotor (3); at least one variable pitch propulsive propeller (4); at least two half-wings (11, 11?) positioned on either side of said fuselage (2); at least one horizontal stabilizer (20) provided with a movable surface (21, 21?); and at least one power plant driving said main rotor (3) and each propulsive propeller (4) in rotation. Said method serves to adjust the lift of said half-wings (11, 11?) and the lift of the horizontal stabilizer (20) so that the collective pitch of said blades (31) of said main rotor (3) is equal to a setpoint collective pitch, so that the longitudinal cyclic pitch of said blades (31) of said main rotor (3) is equal to a setpoint longitudinal cyclic pitch, and so that the lateral cyclic pitch of said blades (31) of said main rotor (3) is equal to a setpoint lateral cyclic pitch during a stabilized stage of flight.

Abstract: A method for equalizing rolling moments at high advance ratios is disclosed including impelling an aircraft in a forward direction at an airspeed by means of a thrust source and rotating a rotor of the aircraft at an angular velocity with respect to the airspeed effective to cause a positive total lift on each blade due to air flow over the blades in the retreating direction when the blade is moving in the retreating direction. The rotor includes an even number of blades placed at equal angular intervals around the rotor hub. One or both of cyclic pitch and rotor angle of attack are adjusted such that a rolling moment of the retreating blade due to reverse air flow is between 0.3 and 0.7 times a rolling moment on the advancing blade due to lift.

Abstract: The invention relates to a compound helicopter (1) comprising a fuselage (2), at least one engine (14) and a main rotor (11) driven by said at least one engine (14). At least one pair of fixed wings are mounted in an essentially horizontal plane on a left hand and a right hand side of the fuselage (2) and horizontally oriented propulsion devices (12, 13) are mounted to each of said fixed wings, said fixed wings encompassing each a drive shaft (16) from said at least one engine (14). Each fixed wing comprises a lower main wing (18) and an upper secondary wing (19) being connected to each other within an interconnection region (22). The propulsion devices (12, 13) are arranged at said interconnection region (22) and said upper secondary wing (19) houses the drive shaft (16) from said at least one engine (14).

Abstract: The present invention is related to a compound helicopter (1) with a main rotor (13) providing lift, a pair of additional propulsion devices (14, 15) providing thrust and anti-torque and a fixed wing structure (16, 17, 26) on each side providing additional lift during horizontal cruise flight. The propulsion devices (14, 15) are arranged at each side of a fuselage body (2) with two tail booms (7, 8), one arranged at each side of said fuselage body (2), each of both tail booms (7, 8) having one of both propulsion devices (14, 15) arranged at its boom rear end (9). Each of the two tail booms (7, 8) houses an engine (21) and a drive shaft (24) driving the corresponding propulsion device (14, 15).

Abstract: An aircraft (1) comprising a fuselage (2), a rotary wing (10) having two contrarotating main rotors (12) arranged in tandem above the fuselage (2), at least one propulsion member (20), and a power plant (30). Each propulsion member (20) is carried by a rear portion (3) of the fuselage. The aircraft (1) includes an interconnection system (40) providing a permanent connection between the power plant (30) and the rotary wing (10), except in the event of a failure or during training, the aircraft (1) having differential control means (50) for controlling the cyclic pitch of the blades of the main rotors (12) to control the aircraft (1) in yaw, and inhibition means (60) for inhibiting each propulsion member (20).

Abstract: A rotor system for a rotorcraft includes a rotor hub having a plurality of rotor blade pairs mechanically coupled to a rotor mast. A pitch link assembly is mechanically coupled to each rotor blade pair for controlling the pitch angle of each rotor blade pair in tandem. Each rotor blade pair has an upper rotor blade and a lower rotor blade. The plurality of rotor blade pairs rotor in a single direction and about a single axis of rotation.

Abstract: The system of the present application represents a rotor hub for a rotorcraft and a rotorcraft incorporating the rotor hub. The rotor hub is represented as having multiple rotor disk assemblies, each rotor disk assembly rotating in the same direction about the same mast axis of rotation. In the preferred embodiment, each rotor disk assembly has three rotor blades. The upper rotor disc assembly and the lower rotor disk assembly are separated by approximately 2.5% of the rotor disk diameter, at least to take advantage of “wake contraction”.

Abstract: A rotor system for a rotorcraft having at least one rotor blade pair operably associated with a differential pitch assembly operably for controlling a pitch angle of an upper rotor blade and the lower rotor blade in the rotor blade pair. Operation of the differential pitch assembly changes the pitch of the upper rotor blade more severely than the pitch of the lower rotor blade. As such, the rotor system is configured to provide optimum pitch of the upper and lower rotor blades during a helicopter mode and an airplane mode.

Abstract: A system and method to control flight of an aircraft. The aircraft having an engine with a rotatably nozzle assembly configured to create forward propulsion and yaw control of the aircraft. The engine exhaust passing through the nozzle is redirected with a valve disposed within the nozzle. Lift is created with a lift system carried by the wing of the aircraft. Additional lift is created during flight with a retractable wing extension disposed within the wing of the aircraft.

Abstract: A safe, quiet, easy to control, efficient, and compact aircraft configuration is enabled through the combination of multiple vertical lift rotors, tandem wings, and forward thrust propellers. The vertical lift rotors, in combination with a front and rear wing, permits a balancing of the center of lift with the center of gravity for both vertical and horizontal flight. This wing and multiple rotor system has the ability to tolerate a relatively large variation of the payload weight for hover, transition, or cruise flight while also providing vertical thrust redundancy. The propulsion system uses multiple lift rotors and forward thrust propellers of a small enough size to be shielded from potential blade strike and provide increased perceived and real safety to the passengers. Using multiple independent rotors provides redundancy and the elimination of single point failure modes that can make the vehicle non-operable in flight.

Abstract: A method of controlling and regulating a rotorcraft presenting a speed of advance that is high and stabilized, the rotorcraft including at least a main lift rotor (10), at least one variable pitch propulsion propeller (6), and at least one power plant for driving the main rotor(s) (10) and at least one propeller (6), said method consisting in using a first loop for regulating pitch or attitude, and a second loop for regulating speed by means of a control over the mean pitch of the propulsion propeller(s) (6), wherein the method further consists in controlling the deflection angle of a horizontal tailplane (30, 25, 35) by using a third loop for controlling and regulating said deflection angle of the horizontal tailplane (30, 25, 35) in order to minimize the total power consumed by the main rotor (10) and the propulsive propeller(s) (6), for a given speed and attitude.

Abstract: The present invention relates to an aircraft (1) comprising an airframe (2) provided with a fuselage (10) and fixed wings (20), a rotary wing (30), at least two propellers (41, 42), and a power plant suitable for driving said rotary wing (30) and said propellers (41, 42) into rotation.

Abstract: A safe, quiet, easy to control, efficient, and compact aircraft configuration is enabled through the combination of multiple vertical lift rotors, tandem wings, and forward thrust propellers. The vertical lift rotors, in combination with a front and rear wing, permits a balancing of the center of lift with the center of gravity for both vertical and horizontal flight. This wing and multiple rotor system has the ability to tolerate a relatively large variation of the payload weight for hover, transition, or cruise flight while also providing vertical thrust redundancy. The propulsion system uses multiple lift rotors and forward thrust propellers of a small enough size to be shielded from potential blade strike and provide increased perceived and real safety to the passengers. Using multiple independent rotors provides redundancy and the elimination of single point failure modes that can make the vehicle non-operable in flight.

Abstract: A safe, quiet, easy to control, efficient, and compact aircraft configuration is enabled through the combination of multiple vertical lift rotors, tandem wings, and forward thrust propellers. The vertical lift rotors, in combination with a front and rear wing, permits a balancing of the center of lift with the center of gravity for both vertical and horizontal flight. This wing and multiple rotor system has the ability to tolerate a relatively large variation of the payload weight for hover, transition, or cruise flight while also providing vertical thrust redundancy. The propulsion system uses multiple lift rotors and forward thrust propellers of a small enough size to be shielded from potential blade strike and provide increased perceived and real safety to the passengers. Using multiple independent rotors provides redundancy and the elimination of single point failure modes that can make the vehicle non-operable in flight.

Abstract: An aircraft (1) having a fuselage (2), the aircraft (1) comprising a rotary wing (9) above the fuselage (2) and an extra fixed wing (10), the rotary wing (9) being above both the fuselage (2) and the fixed wing (10), said fixed wing (10) comprising at least one closed wing (20) comprising a first half-wing (21) and a second half-wing (22). Each half-wing (21, 22) is provided with a top lift portion (30) and a bottom lift portion (40), said bottom lift portion (40) of a half-wing being arranged in the wake (S) of the top lift portion (30) of that half-wing, the wake (S) being generated by a stream of air (F) coming from said rotary wing (9) and impacting against the top face (30?) of the top lift portion (30) when said aircraft (1) has a forward speed less than a predetermined threshold.

Abstract: A rotor aircraft has an engine, a propeller, wings, and a rotor. An electric motor is coupled to the rotor drive shaft for applying torque to the rotor drive shaft. The electric motor is sized to supply all of the torque to pre-rotate the rotor to a selected speed prior to liftoff of the aircraft. The wings are capable of providing substantially all of the lift required during forward flight at a cruise speed. The rotor being is capable of being trimmed to provide substantially zero lift and auto-rotate at cruise speed. Sensors sense flight conditions of the aircraft and provide signals to a controller that selectively causes the electric motor to cease applying torque to the rotor drive shaft during autorotation at cruise speed. The controller also causes the electric motor to apply torque to the rotor drive shaft if the sensors indicate additional rotor speed is needed.

Abstract: In order to regulate a power plant (105) having a gas generator (1) and a free turbine (3) to drive a rotary wing, a first speed of rotation (NTL) of the free turbine (3) is regulated on a first setpoint value (NTL*) equal either to a regulation term (NRc) or to a predetermined setpoint threshold (NTL*). The regulation term (NRc) is a function of a third speed of rotation (NR) of said rotary wing in accordance, where NRc=NR*(1?d), “d” representing a non-zero constant lying in the range 0 to 1.

Abstract: An aircraft features a source of forward thrust on a fuselage having a helicopter rotor assembly and an asymmetric primary wing configuration providing more wing-generated lift on one side of the fuselage than the other. The primary wing configuration counteracts the rotor's dissymmetry of lift during forward cruising, and reliance on the separate thrust source for such cruising reduces demand on the main rotor, keeping the angle of attack on the rotor blades low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. In some embodiments, an oppositely asymmetric tail wing or horizontal stabilizer acts alone, or together with an offset vertical stabilizer laterally outward from the tail, to counteract yaw-inducing drag of the primary wing.

Abstract: An aircraft (1) having a fuselage (2), a power plant (10), a rotary wing (15) having at least one main rotor (16), and a fixed wing (20) comprising two half-wings (21, 22) extending on either side of the fuselage (2). The aircraft (1) also has at least two propulsive propellers (30) on either side of the fuselage (2). Each is positioned on respective ones of the half-wings (21, 22), and an anti-torque and yaw-control tail rotor (35). A transmission system (40) connects the power plant (10) to each main rotor (16) and the tail rotor (35). The transmission system (40) connects the power plant (10) to each propeller (30) via a respective differential mechanism (50) that is controllable on request so that each propeller (30) can be driven in cruising flight and need not be driven in rotation by the power plant (10) on the ground or while hovering.

Abstract: A compound aircraft features variable incidence wings, a thruster, a rotor and a clutch connecting the engines to the rotor. Upon reaching a suitable forward speed, the control system of the compound aircraft unloads the rotor and disengages the clutch, disconnecting the rotor from the engines. The control system configures the cyclic and collective pitch effectors to cause the rotor to autorotate. The control system selects an autorotation rotational speed that is adequately rapid to prevent excessive deformation of the rotor blades due to aerodynamic forces acting on the blade and that is adequately slow to prevent excessive compressibility effects.

Abstract: A safe, quiet, easy to control, efficient, and compact aircraft configuration is enabled through the combination of multiple vertical lift rotors, tandem wings, and forward thrust propellers. The vertical lift rotors, in combination with a front and rear wing, permits a balancing of the center of lift with the center of gravity for both vertical and horizontal flight. This wing and multiple rotor system has the ability to tolerate a relatively large variation of the payload weight for hover, transition, or cruise flight while also providing vertical thrust redundancy. The propulsion system uses multiple lift rotors and forward thrust propellers of a small enough size to be shielded from potential blade strike and provide increased perceived and real safety to the passengers. Using multiple independent rotors provides redundancy and the elimination of single point failure modes that can make the vehicle non-operable in flight.

Abstract: A method of controlling the yaw attitude of a hybrid helicopter including a fuselage and an additional lift surface provided with first and second half-wings extending from either side of the fuselage, each half-wing being provided with a respective first or second propeller. The hybrid helicopter has a thrust control suitable for modifying the first pitch of the first blades of the first propeller and the second pitch of the second blades of the second propeller by the same amount. The hybrid helicopter includes yaw control elements for generating an original order for modifying the yaw attitude of the hybrid helicopter by increasing the pitch of the blades of one propeller and decreasing the pitch of the blades of the other propeller, the original order is optimized as a function of the position of the thrust control to obtain an optimized yaw control order that is applied to the first and second blades.

Abstract: A safe, quiet, easy to control, efficient, and compact aircraft configuration is enabled through the combination of multiple vertical lift rotors, tandem wings, and forward thrust propellers. The vertical lift rotors, in combination with a front and rear wing, permits a balancing of the center of lift with the center of gravity for both vertical and horizontal flight. This wing and multiple rotor system has the ability to tolerate a relatively large variation of the payload weight for hover, transition, or cruise flight while also providing vertical thrust redundancy. The propulsion system uses multiple lift rotors and forward thrust propellers of a small enough size to be shielded from potential blade strike and provide increased perceived and real safety to the passengers. Using multiple independent rotors provides redundancy and the elimination of single point failure modes that can make the vehicle non-operable in flight.

Abstract: An aircraft features a nose mounted propeller on a fuselage having a typical helicopter rotor assembly. By reducing the amount of forward thrust needed from the main rotor, the propeller allows greater forward speeds as the angle of attack on the rotor's blades can be kept low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. By reducing the maximum angle of attack experienced by the main rotor during its rotation during forward cruising from that of a conventional helicopter but still using the main rotor to generate lift, the addition of wings extending from both sides of the fuselage can be avoided. The aircraft may be flown in a forward direction in a generally horizontal orientation, as the nose does not have to be pitched downward to create thrust from the main rotor.