Abstract: The present invention relates to a method and to a device (1) for correcting measurement errors of a magnetometer (2) mounted on a vehicle (3). According to the invention:a theoretical corrective model [A].Hm+a.Hm'+Hp=[M].H is defined, in which [A], a and H are elements to be determined, Hm is the measured field, Hm' the time derivative of Hm, H the effective field and [M] a transformation matrix;a vector error E=[M].H-([A].Hm+a.Hm'+Hp) is defined;the square of the error thus defined is determined; andthe coefficients of the model which minimize the sum of the squares of the errors for all the measurements taken are identified.

Abstract: An apparatus has at least one pendulous member mounted on a rotor so as to be able to swing about an axis of pendular motion spaced at a distance from the center of inertia of the pendulous member. The pendulous member is pivotably mounted on its own axis of rotation parallel to the axis of pendular motion and situated substantially closer to the center of inertia of the pendulous member than to the axis of pendular motion.

Abstract: The device comprises, between two blades and their members linking them to the hub, three levers articulated by ball joints to the members and to the hub, the two levers pivoting on the third one about axes of pivoting parallel to each other and perpendicular to the common plane passing through the centres of the ball joints. At least one of the levers comprises at least one drag damper.

Abstract: A flow-straightening stator is fixed into the duct downstream of the rotor mounted so that it rotates in this duct, and includes vanes with aerodynamic profile which straightens out the airflow downstream of the rotor substantially along the axis of the duct, and are each inclined to the radial direction, from the axis of the duct towards its periphery, and in the opposite direction from the direction of rotation of the rotor, and/or inclined at a slant, from the center of the duct to its periphery and from upstream to downstream of the duct.

Abstract: The process produces a sandwich composite panel including at least one cellular core having on its faces skins of fiber/resin composite material which are fastened to the cellular core. At least one strip of composite material is formed, the profile of which corresponds to that of the peripheral flank of the panel preform. The strip is applied against the flank of the panel preform. The preform, provided with at least one such strip on its border, is subjected to a temperature, rise, without positive pressure being applied, until the resin of the strip has cured and then, after the curing of the strip and before the curing of the resin of the skins, is subjected to the continuation of the temperature rise, with positive pressure being applied.

Abstract: The device comprises, in addition to the conventional non-rotating plate and rotating plate of a swashplates device, a secondary rotating plate which can move in translation with the non-rotating plate but which cannot be inclined, and, for each blade, an articulated link with two levers which are articulated together and the first of which is articulated to the secondary rotating plate. The second lever is also articulated to the pitch rod controlling the corresponding pitch lever, and it is moreover articulated to a stationary point of the rotating plate. The inclinations of the plates give rise to angular manoeuvres of the levers of each link in order to actuate the pitch rod and control the pitch of the corresponding blade.

Abstract: A method of manufacturing a vane for a counter torque device includes extruding a hollow metal section of cross-section corresponding to the aerodynamic profile of the vane, in cutting off a section portion of length not substantially less than the span of the vane, and in arranging each end of the section portion as an end fitting with at least one fastening tab, either by machining and deformation of the ends of the section portion, or by fitting end fittings attached to its ends.

Abstract: The composite vane is moulded by injecting resin into a preform of layers of reinforcing fibres according to the RTM method. The skins of its main vane section as well as of its root and tip via which it is connected to the flow-straightener central body and to part of the duct are laminated with a pile of at least three layers of reinforcing fibres, and complementary piles at the root and tip exhibit at least one fastening tab. The central body is made of metal or composite and the composite vanes are interchangeable, or the vanes and the central body are injection-moulded as a single piece using the RTM method.

Abstract: The device for controlling the pitch of the blades of a rotor using a mechanism having swashplates includes an auxiliary plate mounted on the non-rotating plate of the mechanism and which is secured in terms of rotation to the rotating plate of this mechanism and, for each blade, an articulated link in series with the corresponding pitch rod to which it is articulated, and including at least one arm articulated to the rotating plate, each articulated link being controlled by a lever articulated to it and to the auxiliary plate which is off-centered to the desired value so that each of the control levers controls the itch of the corresponding blade by applying a bicyclic component to it, the amplitude and phase of which component depend on the eccentricity of the auxiliary plate as defined with respect to the non-rotating plate.

Abstract: A flow-straightener with stationary vanes and aerodynamic profile is mounted downstream of the rotor with blades in the transverse duct passing through the fairing at the tail of the helicopter. The blades of the rotor are distributed angularly about the axis of the rotor with uneven azimuth modulation, such that any angle between two arbitrary blades of the rotor is different from any angle between two arbitrary vanes of the flow-straightener.

Abstract: The device comprises anti-cone stops projecting outwards from a common ring that can rotate about the rotor axis on the top face of the hub and flyweights are each individually joined to the ring for driving the latter in rotation from the "ground" position, in which each anti-cone stop is facing an upper bearing shoe of the corresponding blade, to the "flight" position, in which the anti-cone stops are retracted, returning them to the "ground" position.

Abstract: For producing connections made from composite material for structures having at least two hollow or non-hollow bars, interconnected by at least one hollow connecting joint, separate production takes place of blanks of said different parts with the definitive shapes, but in which the impregnation resin for the assembly of said blanks has not yet been introduced, after which they are assembled by thermosetting resin transfer molding, so as to produce the resin matrix of the connecting joint or the complete structure at the same time as the assembly. The blanks of the connecting joints are obtained by compressing a planar textile complex formed from hot preformable textile fibers between a cavity of a shaping mold and a countermold, by cutting and folding down onto the countermold the overlap parts and performing a thermal preforming cycle.

Abstract: The blades of the rotor which can rotate in the transverse duct have an angular distribution according to an uneven azimuth modulation given by the following sinusoidal law:.THETA.n=n.times.360.degree./b+.DELTA..THETA. sin(m.times.n.times.360.degree./b)where .THETA.n is the angular position of the nth of the blades counted in series from an arbitrary origin, b is the number of blades, m is a whole number chosen from 1 to 4, which is not prime with the number b of blades, chosen from 6 to 12, and .DELTA..THETA. is chosen to be greater than or equal to a minimum value .DELTA..THETA. min, which is such that the product .DELTA..THETA. min.times.b is chosen within a range of values extending from 1.5 radian to 1 radian.

Abstract: For each blade, the cuff which is rigid in torsion, surrounding the corresponding rotor attachment twistable arm, bears two opposed pitch levers each articulated to one respectively of two intermediate connecting rods which are moreover articulated to one and the same transmission lever on either side of a pivoting link by means of which this lever pivots on a pivot secured to the rotor mast. The transmission lever is additionally articulated to the pitch-control rod at a point which is offset with respect to its pivoting link. A crossmember is articulated to the connecting rods and interacts with an assembly having a drag damper, this assembly itself being articulated to a fixed point secured in terms of rotation to the rotor mast.

Abstract: The invention relates to a helicopter fuselage of the type including a central structure to which are linked a front structure, a rear structure and a landing gear, and which supports a transmission gearbox, a main rotor and at least one engine (50), and of the type in which the central structure includes a skeleton (16) fitted with covering elements which define the external shape of the fuselage.According to the invention, the skeleton (16) of the central structure exhibits substantially the shape of a regular hexahedron consisting of skeleton panels (28, 30, 32, 34, 36, 38) assembled together.The invention finds an application especially for producing light helicopters.

Abstract: An electrical connection element intended for the electrical connection of shielded bundles of electrical cables wherein at least some of the electrical cables are shielded. The connection element is composed of an outer tube and an inner tube. The outer robe has a hollow interior space and a first portion adapted to be joined to a bundle of electrical cables having a shield, the electrical cables passing through the hollow internal space of the outer tube. The outer tube has a second portion adapted to be joined to a connector associated with the bundle of electrical cables and intended to make electrical connection with an interacting connector associated with at least one other bundle of electrical cables. The shield of the bundle of electrical cables surrounds the outer tube and is in contact with an external face of the outer tube.

Abstract: The present invention relates to a method of assisting the piloting of an aircraft at low altitude. According to the invention, a hypothetical curve associated with an optimal theoretical trajectory for clearing an obstacle is calculated and, in the field in front of the aircraft: all the obstacles situated in a search area are determined; the tops of the obstacles determined are compared with the hypothetical curve; an obstacle is defined as a dangerous obstacle if the top of the obstacle is situated highest with respect to the hypothetical curve; and the coordinates of the top of the dangerous obstacle are communicated.

Abstract: In the rotor, the pitch lever of each blade is connected to the tab of the pitch control spider by a ball joint mounted on a wrist pin and received with clearance in an oblong opening in a ring. The axially offset bearing surfaces of the cuff of the blade are mounted with a radial clearance in the bearings of the hub on which they swivel about the pitch axis of the blade. These radial clearances enable contacts of the ball joint against the edge of the opening on the side of the ends of its minor axis, but prevent these contacts on the side of the ends of the major axis of the oblong opening.

Abstract: A device and a machine for connecting connection elements into housings of connectors, the device including a body which can be moved in the direction of the connector, an insertion tool associated with the body via removable linkage means and provided with means for gripping a connection element to be inserted, and means for controlling the opening and closure of the gripping means. The device has elastic means located between the insertion tool and the gripping means which is capable of acting along the longitudinal axis of insertion of the connection element into the housing of the connector. The removable linkage means are defined by an articulation having a center of rotation which .joins the tool to the body, the center of rotation being coincident with the longitudinal axis, and indexing means associated with the body in order to act on the articulation so as to align the tool with the body.

Abstract: The rotor is supported within the duct by a stationary flow-straightener with vanes connecting the wall of the duct to a central body housing the mechanism for driving the rotor. This mechanism is surrounded by a casing equipped with radial arms bearing removable means for fastening to an internal flange of the body, so as to fasten the flow-straightener and the casing rigidly to one another, and both into the duct.