Abstract: A blade in which the aerodynamic profiles of a blade root, a blade neck and a central part of a profiled zone of the blade respectively comprise a leading edge section and a trailing edge section that are symmetrical to each other relative to an axis of symmetry. The present disclosure also concerns a method for constructing such a blade. The axis of symmetry is perpendicular to a segment connecting the leading edge to the trailing edge of each profile and is positioned in the middle of the segment. An intermediate upper surface section and an intermediate lower surface section connect the leading edge section and the trailing edge section in order to respectively form a lower surface of the aerodynamic profile.

Abstract: A method for controlling at least a first turboshaft engine and a second turboshaft engine of a rotorcraft, which set a common kinematic linkage in motion, the rotorcraft having an output electric machine cooperating with a first output kinematic linkage of the first turboshaft engine, the rotorcraft having an input electric machine cooperating with a gas generator of the second turboshaft engine. The method includes the following steps: supplying fuel to the first turboshaft engine, operating the output electric machine in electrical energy generator mode, supplying fuel to the second turboshaft engine, and operating the input electric machine in motor mode in order to supply a second non-zero power to said common kinematic linkage.

Abstract: A rotorcraft having an antivibration system, the antivibration system being arranged at the interface between a fuselage of the rotorcraft and a casing of a main power transmission gearbox, or “MGB”, in order to transmit rotary motion generated by an engine of the rotorcraft to a main rotor providing the rotorcraft at least with lift, and possibly also propulsion, the antivibration system including calculation means for analyzing as a function of time the dynamic excitation and the resulting vibration transmitted to the fuselage of the rotorcraft.

Abstract: A blade in which the aerodynamic profiles of a blade root, a blade neck and a central part of a profiled zone of the blade respectively comprise a leading edge section and a trailing edge section that are symmetrical to each other relative to an axis of symmetry. The present disclosure also concerns a method for constructing such a blade. The axis of symmetry is perpendicular to a segment connecting the leading edge to the trailing edge of each profile and is positioned in the middle of the segment. An intermediate upper surface section and an intermediate lower surface section connect the leading edge section and the trailing edge section in order to respectively form a lower surface of the aerodynamic profile.

Abstract: A rotorcraft having an antivibration system, the antivibration system being arranged at the interface between a fuselage of the rotorcraft and a casing of a main power transmission gearbox, or “MGB”, in order to transmit rotary motion generated by an engine of the rotorcraft to a main rotor providing the rotorcraft at least with lift, and possibly also propulsion, the antivibration system including calculation means for analyzing as a function of time the dynamic excitation and the resulting vibration transmitted to the fuselage of the rotorcraft.

Abstract: A coupling device (9, 10) providing end-to-end coupling between link shafts (4) and a supercritical transmission shaft (5) for driving a rotorcraft rotor (1). Since the transmission shaft (5) is movable in angular deflection (B), spherical bearing surface friction members (12, 13) are incorporated in the bearings (7) for mounting the transmission shaft (5) on a carrier structure (8). The friction members (12, 13) are caused to press against each other in dry friction via respective friction surfaces. A first friction member (12) is secured to the carrier structure (8) and a second friction member (13) is secured to a cage (14) for housing rolling members (15) carried by the transmission shaft (5). The cage is itself engaged on the transmission shaft (5) to accompany it in its movement in angular deflection (B).

Abstract: An aircraft (1) provided with a main gearbox (3) fastened to a load-bearing structure (2) via at least three suspension bars (5). An active vibration absorber (10) is fastened around each suspension bar (5), each vibration absorber (10) being provided with a first mass (11) connected to the associated suspension bar (5) via first resilient means (21), and with a second mass (12) connected to the first mass (11) via second resilient means (22), said vibration absorber (10) having a force generator (15) interposed between the first mass (11) and the second mass (12) and inputting a control force on being instructed by a control unit (16) as a function of information coming from at least one first measurement sensor (17) for sensing monitoring parameters for monitoring the associated suspension bar.

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: A device for launching and recovering a drone for being fastened to an aircraft is provided. The device includes a docking plate for a drone provided with a securing/releasing mechanism for the drone. The docking plate being secured to a flared guide for guiding the drone towards the docking plate.

Abstract: A coupling device (9, 10) providing end-to-end coupling between link shafts (4) and a supercritical transmission shaft (5) for driving a rotorcraft rotor (1). Since the transmission shaft (5) is movable in angular deflection (B), spherical bearing surface friction members (12, 13) are incorporated in the bearings (7) for mounting the transmission shaft (5) on a carrier structure (8). The friction members (12, 13) are caused to press against each other in dry friction via respective friction surfaces. A first friction member (12) is secured to the carrier structure (8) and a second friction member (13) is secured to a cage (14) for housing rolling members (15) carried by the transmission shaft (5). The cage is itself engaged on the transmission shaft (5) to accompany it in its movement in angular deflection (B).

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: 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: An aircraft (1) provided with a main gearbox (3) fastened to a load-bearing structure (2) via at least three suspension bars (5). An active vibration absorber (10) is fastened around each suspension bar (5), each vibration absorber (10) being provided with a first mass (11) connected to the associated suspension bar (5) via first resilient means (21), and with a second mass (12) connected to the first mass (11) via second resilient means (22), said vibration absorber (10) having a force generator (15) interposed between the first mass (11) and the second mass (12) and inputting a control force on being instructed by a control unit (16) as a function of information coming from at least one first measurement sensor (17) for sensing monitoring parameters for monitoring the associated suspension bar.

Abstract: A device (10) for launching and recovering a drone (5), the device being suitable for being fastened to an aircraft. The device includes docking means (20) for a drone (5), the docking means (20) being provided with securing/releasing means (30) for the drone (5), said docking means (20) being secured to flared guide means (40) for guiding the drone (5) towards said docking means (20).

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.