Abstract: The present invention relates to a suspension device for a transmission box (BT) of a rotary-wing aircraft, including bearing pieces (2) connected to the upper part (3) of the transmission box (BT), a suspension system (SU) which connects the lower part (9) of the transmission box (BT) to the fuselage (F) of the aircraft and which includes suspension leaves (5), and resonator means (7) which are associated respectively with the said bearing pieces (2) and which include a mass support (13) secured to the associated suspension leaf (5) and equipped with a flapping mass (MB). According to the invention, the said device additionally includes tuning means (18, 19) associated with the said resonator means (7) and capable of tuning their natural frequencies.

Abstract: The present invention relates to a device (1) for damping the vibrations of a structure (2) subjected to dynamic stresses, of the type including a main mass (3) mounted on an elastic plate (4) which is itself fitted into the structure (2) whose vibrations are to be damped.According to the invention, the damping device (1) additionally comprises at least one auxiliary mass (5) connected to said main mass (3) and capable of being moved at least substantially parallel to said elastic plate (4) as a function of the control pulses which are received from a computer (9) and are computed from signals output by a first (10) and/or a second accelerometer (11) respectively measuring the vibrations of said structure (2) and those of said main mass (3).

Abstract: An apparatus for shielding a blade against lightning includes a conducting leading edge glove and a conducting cap, distinct from the glove, and overlapping the blade tip across its entire chord. At least the cap has a suction face arm and a pressure face arm of different dimensions at least in the direction of its span. Mechanical devices, such as screws and rivets with protruding shapes, in addition to some glueing, fix the cap on the composite structure of the blade, and are earthed by the cap, forming points where lightning can enter or exit, protecting the surrounding composite structure of the blade against damage. When the blade is mounted on a member for linking to the hub, electrical continuity with this member and the hub is provided.

Abstract: The bidirectional suspension comprises, in order to connect the transmission gearbox to the fuselage, two parallel connecting rods which are articulated to lateral supports on opposite sides of the base of this gearbox and on the same side of the latter as far as their articulations to two transverse levers, each articulated to the fuselage about an axis perpendicular to the connecting rods and substantially parallel to the axis of the rotor. Each of the two levers lie substantially in the extension of the other and are connected to each other via their adjacent ends. Means providing elastic linkages in the direction of the connecting rods and in the direction perpendicular to the latter connect the fuselage to the gearbox and may consist of a single elastic pad.

Abstract: A hingeless rotor including a rotor mast driven in rotation about an axis of the rotor, a hub secured in terms of rotation to the mast, and at least two blades, each of which is, firstly, joined to the hub by a root attachment part comprising at least one arm which can twist about a longitudinal pitch-change axis of the blade and, secondly, equipped with a cuff which is rigid in torsion, surrounding the at least one twistable arm, and the radially external part of the cuff, with respect to the rotor axis is secured in terms of torsion to the blade and to the twistable arm about the pitch-change axis, while the radially internal part of the cuff surrounds, without contact, the at least one twistable arm and exhibits a pitch lever projecting towards the outside of the cuff and joined to a pitch-control rod, wherein, for each blade, an intermediate pitch-control ring which is rigid in terms of torsion about the corresponding pitch-change axis, and which surrounds the corresponding at least one twistable arm is a

Abstract: The folding device comprises a fitting pivoting on a cuff about a folding axis which is offset laterally thanks to two lateral bearings of the fitting journal-mounted about bushings retained in lateral devises of the cuff and which are coaxial about the axis by pegs for centering a maneuvering actuator for maneuvering the fitting and the blade about the folding axis.

Abstract: The suspension device comprises, for linking the base (5b) of the transmission gearbox to the fuselage (6), two parallel rods (14), articulated (15) onto lateral supports (16) fixed to opposite sides of the base (5b) and extending on the same side of the transmission gearbox to their link (19) to structural supports (20) of the fuselage (6). Elastic links (17) provide the suspension at least in the direction perpendicular to the rods (14). In a variant, the rods (14) are linked to the fuselage (6) being articulated on a transverse flexible bar, equipped as required with a central flapping mass, or on transverse levers articulated onto one another by a central articulation and onto the structure. Application to uni-or bidirectional, focal-point and, as appropriate, antiresonant suspension of helicopter main rotors.

Abstract: Device for positioning, locking, and extracting mobile equipment with respect to a fixed support, of the type including two slideway elements 1, 2, one 1 of which is secured to the mobile equipment E and the other 2 of which is secured to the fixed support S, these elements 1, 2 being designed to guide the mobile equipment E in sliding on the fixed support S until complementary connectors secured on the one hand to the said equipment E and on the other hand to the said support S have been coupled together.This device is characterized in that it includes removable insertion tooling comprising means 9, 11, 15 for temporarily catching hold of a load-spreading body 10 on the fixed slideway element 2, it being possible for a press screw 16 to be screwed into this load-spreading body 10 so as to exert, via its end 20, a thrust on the mobile slideway element 1.

Abstract: A device for reducing the vibrations generated on the structure of a helicopter. The helicopter includes a structure with a tail boom and a fin. The structure has a longitudinal vertical mid-plane. The helicopter also has a main lift and propulsion rotor which generate an aerodynamic flow passing through the rotor and induce vibrations on the structure. A damping device for reducing the vibrations has a longitudinal chamber which is equipped with at least one central restriction, which has two elastically urged mobile lateral walls and which is full of a fluid representing an oscillating mass. The damping device is mounted in the tail boom close to the fin so that the direction of travel of the oscillating mass is at least substantially orthogonal to the longitudinal vertical mid-plane.

Abstract: The installation links a supply conductor to an electrical device for de-icing a blade using at least one cable with a first stretch linked to the supply conductor by a connector and to a second stretch with an overhead hook in the form of flattened half loop, itself linked to the device for de-icing the blade by a second connector fitted on the blade, possibly via a straight and flat third stretch and a second overhead hook. The first hook is of nonscreened structure, with an elongate part of substantially flattened rectangular transverse section and with a concavity pointing towards a device for retaining and articulating the blade on a hub.

Abstract: A cyclic stick system for a helicopter includes sensors for measuring at least one parameter representative of the current flight status of the helicopter. In response to the at least one parameter, the cyclic stick system either (1) continuously and automatically recenters the forces on the cyclic stick, thus canceling out the residual static forces, or (2) allows the pilot fully to feel the countering action of the elastic return device on the cyclic stick.

Abstract: The present invention relates to a rotary-wing aircraft, especially such as a helicopter, of the compound type including:a fuselage (2),fixed-wing elements (6) arranged on either side of said fuselage (2),at least one main rotor (4),an anti-torque rear rotor (9), anda rear thruster propeller (14), arranged at the end of the tail boom (8) of said fuselage (2).According to the invention, said rear thruster propeller (14) has a shroud (15).

Abstract: A rudder bar system for a helicopter controlled in yaw by acting on the tail rotor or an equivalent device has a capability, as a function of the parameters representative of the current flight status of the helicopter, of either automatically continuously recentering the forces on the rudder bar, which cancels out the residual static forces and gives the pilot a tactile sensation close to that given by a friction-type rudder bar, or allowing the pilot fully to feel the countering action of an elastic return device such as a spring.

Abstract: System for minimizing the dynamic excitation at the center of gravity of the fuselage of a helicopter, this excitation being brought about by the forces transmitted between the main transmission box and the fuselage, these two components being joined together by suspension bars which each have an elastic linkage device.According to the invention, each elastic linkage device (2) comprises a cylinder (10), subdivided into two chambers (11, 12) by a piston (13) connected by springs to the two corresponding opposite internal faces (10a, 10b) of the cylinder (10), and the chambers (11, 12) of the cylinder (10) are additionally connected to one another by a pipe (17) which has a small cross section compared with that of the cylinder (10). A computer (6) pilots the movement of liquid in said pipe (17).

Abstract: A metal electromagnetic shielding sheath is provided on a multibranched bundle of electrical conductors. The sheath includes sheath elements braided directly on the branches of said bundle, and at least one of the ends of said sheath elements is held captive between two superposed rings gripping the corresponding branch of the bundle.

Abstract: The installation for removing electrostatic charge and passing lightning current between a conductor of each blade of the rotor and a metallic part of the hub comprises at least one conductive member integral with the member for linking the blade to the hub in its angular deflections, and in electrical continuity with the conductor of the blade and held elastically in permanent contact with a conductive terminal integral with the hub and in electrical continuity therewith.

Abstract: Device for illuminating a set (1) of equipment items (3), such as indicators or dials of measurement apparatus (4), which are mounted on an outer face (2E) of a common support (2).According to the invention, this device includes:an electroluminescent plate (5), arranged in such a way that its illuminating face (5I) is opposite said outer face (2E) of said common support (2), spaced away from said outer face, and provided with a plurality of apertures (7);a facing (8) arranged on the non-illuminating face (5E) of said electroluminescent plate (5), and also provided with a plurality of apertures (9); andelectrical power supply means (6) for said electroluminescent plate (5).Illumination of instrument panels, particularly for aircraft.

Abstract: The invention relates to an anti-crash seat with harness for an aircraft.The seat is mounted with limited sliding on at least one substantially vertical support (8), integral with the structure of said aircraft and associated with at least one energy-absorbing device (12), located between said seat and said structure. Advantageously:it is shaped as a bench (2) defining a plurality of seating spaces which are located side by side and each of which is equipped with a safety harness (6);it includes at least one additional energy-absorbing device (16), situated between said structure of the aircraft and a coupling mechanism (17) with locking provided at least at one of said seating spaces; andsaid mechanism (17) for coupling between said bench and said additional device is controlled by the harness (6) associated with said seating space.

Abstract: The rig comprises a vertical electric motor in a shell-type framework carrying a force balance itself supporting either a main rotor in dynamic tests or a complete propulsion assembly with main rotor in endurance tests, or a height extender supporting, on the one hand, an upper shaft line being coupled to a lower shaft line supported in the framework and driven by the motor and, on the other hand, an inverse-thrust rotor mast, driving a hub jig linked to blades mounted inverted so as to exercise a thrust downwards. The mast is linked to the shaft line by a torque meter and is mounted rotating in a bearing supported by a second balance fixed to the height extender. The mast and the upper shaft line are removable with the height extender in order to make the rig multi-purpose and useable for performance, endurance and dynamic tests of helicopter rotors.

Abstract: The present invention relates to a method and a device for correcting measurement errors of a magnetometer mounted on a vehicle. According to the method, a theoretical corrective model is defined in accordance with the following equation: ##EQU1## where ?A!, ?C!i and Hp are elements to be determined, Hm is the measured field, H the effective field, and ?M! is a transformation matrix, and in which a vector error is defined in accordance with the following equation: ##EQU2## where the square of the error thus defined is determined and the coefficients of the model which minimize the sum of the squares of the error moduli for all the measurements taken are identified.