Abstract: An actuator for an aircraft turbine engine nacelle with a one-piece annular rear part, includes an engine assembly having a nut which is capable of rotating but not of translational movement, and a shaft for turning this nut. The actuator also includes a screw assembly having a screw capable of translational movement without rotating, in mesh with the nut, and a ball joint at one end of this screw intended to be fixed to the annular rear part.

Abstract: A rear nacelle assembly for turbojet engine includes an inner structure surrounding a downstream portion of the turbojet engine. In particular, the inner structure is movable in rotation between an operating position in which it forms a downstream fairing and defines an annular stream of cold air with a thrust reverser cowl, and a maintenance position in which the inner structure moves away from the downstream portion. A suspension pylon is further provided to mount the thrust reverser cowl and the inner structure. The thrust reverser cowl slides between an opening position clearing air flow deviation grids and a closing position recovering the air flow deviation grids. Moreover, the thrust reverser cowl is mounted on the suspension pylon by a pivot connection sliding around a main axis, and the inner structure is mounted on the suspension pylon by a pivot connection around the main axis.

Abstract: An afterbody for a turbojet engine having a central axis, provided with a nozzle comprising two doors facing each other between two lateral beams. The doors pivot around axes defining a pivot direction, between a retracted position, in which a middle portion of the downstream edge of the doors forms the edge of the outlet section of the nozzle combined with the downstream edges of the two lateral beams, and a deployed position, in which the middle portions of the downstream edges of the pivoting doors come together so as to block the channel between the two lateral beams in order to reverse the thrust of the turbojet engine gases. The edge of the outlet section of the nozzle further having a crown of noise-reducing chevrons alternating with indentations and the afterbody.

Abstract: A method for controlling a position of a variable nozzle of an aircraft includes the following steps: setting the variable nozzle in a position P(t0) at a time t0 as a preliminary step; step A in which at each instant ti with 1<i<N, an optimal position P(ti) of the variable nozzle is determined according to magnitudes distinctive of the flight of the aircraft; step B measuring a time interval ?ti defined as a difference between ti and t0; and step C by which a displacement of the variable nozzle in a position corresponding to the optimal position P(ti) is authorized when the time interval ?ti is higher than a predetermined minimum threshold.

Abstract: A turbojet engine nacelle includes a thrust reversing device having doors that swing to brake a direct gas flow, guiding it through counter-thrust openings, and the inside of each door has, at the front, a cavity receiving a spoiler turned towards the front when this door is open. The nacelle includes a fixed structure upstream from each door supporting a deflection edge that partially covers the cavity. In particular, the fixed structure supports, on each side, counter-thrust openings, a flank disposed in the continuation of the deflection edge and extending behind the cavity, which is incorporated into a leaf of the door.

Abstract: A single-piece woven fiber structure for fabricating an axisymmetric part of varying diameter made out of composite material, the fiber structure having a portion of frustoconical shape with a large diameter and a small diameter, the ratio between the large diameter and the small diameter being not less than 2. The fiber structure is formed by winding layers of warp and weft yarns that are woven on a mandrel having a profile that is defined as a function of the profile of the part to be fabricated with warp yarn take-up. For each layer of yarns, the weft yarns are angularly distributed on a single diameter in a zone of the large diameter of the portion of frustoconical shape and on at least two different diameters in a zone of the small diameter of the portion of frustoconical shape in order to form at least two superposed plies of weft yarns.

Abstract: A method of measuring the thickness of a coating layer of a workpiece, the layer being formed on a substrate of the workpiece. The method comprises several steps. First, feeding a probe alternating electrical signal to induction device in order to induce a magnetic field in the workpiece. Second, measuring at least one physical characteristic that varies as a function of the magnetic field induced in the workpiece. Third, determining first and second values of an indicator, the values being determined respectively from measurements of the physical characteristic taken when the electrical signal has first and second given frequencies. Forth, calculating the difference between the first and second values of the indicator and determining the thickness of the coating layer as a function of the difference and of predetermined data correlating: the difference between the values of the indicator; and corresponding values for thicknesses of the coating layer.

Abstract: An assembly for a turbojet engine includes a pylon, a nacelle supported by the pylon, and a locking device interposed between the pylon and a cowl of the nacelle. The cowl slides between operating and maintenance positions. The locking device is movable between active and inhibited positions, and the device allows an operation mode in the active position and a maintenance mode in the inhibited position. In particular, the locking device comprises a rocker to maintain the cowl to the pylon, and the rocker includes an inhibiting lever and an activation lever. The inhibiting and activation levers are mounted on a switching shaft of the locking device. The inhibiting lever is set in rotation through an actuator, providing direct access from a bypass flow duct in the active position while the activation lever is set in rotation from the bypass duct in the inhibited position.

Abstract: A nacelle for an aircraft turbojet engine includes: a substantially cylindrical internal envelope, a substantially cylindrical external envelope, a downstream partition wall and an upstream partition wall secured to the cylindrical internal envelope and a front lip disposed forward of the upstream partition wall. The cylindrical internal envelope includes an upstream portion including an acoustic shroud connected, by an attachment flange, to a downstream portion including a fan casing. In particular, the front lip is extended and disposed over the upstream partition wall by presenting a downstream edge between the upstream and downstream partition walls in order to be secured to a homologous edge of the cylindrical external envelope so as to arrange a maintenance access to the attachment flange.

Abstract: The present disclosure relates to a propulsion unit for an aircraft including a nacelle which surrounds a turbojet engine. The nacelle has an inner structure surrounding a downstream compartment of the turbojet engine, and the inner structure includes two annular half-portions. The propulsion unit also includes a rail/guide unit and to move the annular half-portions between a working position and a maintenance position. In particular, the rail/guide unit radially moves away the annular half-portions relative to a longitudinal axis of the nacelle, during a translation movement of the annular half-portions. The nacelle is provided with a connecting rod which is connected to the annular half-portions and to the turbojet engine and so that the connecting rod contributes to rotate the annular half-portions about the rail.

Abstract: An air intake structure for a turbojet engine nacelle includes an inner panel to be attached to a fan casing, and an external panel capable of a translational movement in a longitudinal direction of the nacelle. The external panel incorporates a portion of an air inlet lip able to provide a junction between the inner panel and the external panel, and each of the air inlet lip portion and the inner panel is equipped, at least in the region of a joining end, with an acoustic attenuation structure. In particular, at least one of the joining ends is equipped with a radial buffer able to come into contact with a corresponding joining flange exhibited by the other joining end when the external panel is in a closed position.

Abstract: An actuating assembly for an aircraft engine thrust reverser includes a drive shaft bearing a master pinion; a ball screw bearing a slave pinion engaging with the master pinion; a nut capable of translating over the ball screw as a result of the rotation of the ball screw; an extension tube rigidly secured to the nut and a lock assembly to block the rotation of the drive shaft in a so-called direct jet position of the reverser. The extension tube includes, at its free end, a member for connecting to a portion of the reverser prior to being actuated. In particular, the lock assembly includes an abutment secured to the drive shaft, and a cotter moveable between a locking position and an unlocking position. The reduction ratio (R) between the slave and master pinions is even.

Abstract: A variable-section nozzle for an aircraft nacelle includes a deformable portion of which is movable between a narrow section position and a wide section position. In particular, the variable-section nozzle includes piezoelectric actuators and a controller to control the piezoelectric actuators in order to displace the deformable portion between the narrow and wide section positions. The piezoelectric actuators can be disposed on at least one faces of the deformable portion or be disposed end-to-end to form actuating rods.

Abstract: The present disclosure relates to a front frame for an aircraft nacelle comprising a turbojet mounted on a suspension strut, said nacelle comprising a thrust reverser including an actuator designed to open a thrust reversal cowling. The front frame comprises a tubular torsion box, a first straight attachment edge intended to attach the box to a turbojet casing and a second straight attachment edge intended to attach the box to air flow diversion means. The front frame is arranged to transmit tensile and compressive loads between the turbojet casing and the air flow diversion means and torsion loads absorbed by the suspension strut. The front frame is characterized in that the tubular torsion box has a semi-elliptical or elliptical cross-section.

Abstract: The present disclosure relates to a thrust reverser for a turbojet engine nacelle, including cowls that move backwards to open the thrust reverser. Each cowl includes a primary axial guide rail that receives most of the loads of the cowl, and secondary rails guiding an outer portion of each cowl. The thrust reverser includes a rear end stop for each cowl is arranged on the primary axial guide rails.

Abstract: A locking device includes a locking pair having a bolt to engage with a retainer and a detection linkage. The bolt is movably mounted against a spring which tends to return the bolt to a position spaced apart from the retainer. The detection linkage is also movably mounted between an unlocked position where the detection linkage allows unlocking of the bolt and the retainer. In particular, a portion of the bolt then engages with the detection linkage by means of a detecting part of the detection linkage to block a possible return of the detection linkage towards a locked position where the detection linkage engages with the portion of the bolt so as to oppose to unlocking of the bolt. The detecting part irreversibly drives the detection linkage to its unlocked position even when one locking pair is unlocked.

Abstract: The present disclosure provides a thrust reverser device that is integrated in an aircraft nacelle. Blocking flaps are stored inside a mobile cowl disposed in a downstream section of the nacelle, under deflection cascade assemblies during direct-jet operation of the nacelle. Various devices are provided for executing the passage from direct-jet operation to reverse-jet operation in two stages: the mobile cowl moves in translation towards the downstream end of the nacelle; and each flap is then deployed in the main air flow path.

Abstract: A method for assessing damage to a composite material covered with a polyurethane-type paint is provided. Two separate criteria are measured on a spectrogram obtained by infrared spectrometry, thereby characterizing thermal ageing of the paint, each separate criteria being a measurement on a curve of a spectrum of the spectrogram of a height of a particular peak, thereby giving two independent assessments of the thermal ageing. Then, the two separate criteria are combined together in order to obtain a result of a level of the damage.

Abstract: A thrust reverser of a turbofan pod is provided that includes movable cowlings that retract relative to stationary front structure to reveal stationary or movable thrust reverser cascades, as well as a secondary variable nozzle section connected to the movable cowlings by guiding means enabling movement controlled by actuators engaged with the front structure to apply an axial thrust. The actuators are directly connected to the secondary nozzle, and in that the thrust reverser comprises latches connected to the movable cowlings, having two positions providing, alternately, latching onto the front structure or latching onto the control of the secondary nozzle.

Abstract: A method for assembling a set including an inner wall, a shrouded outer wall and an intermediate element, each presenting substantially circular sections, the shrouded outer wall presenting a shape substantially complementary to a shape of outer and inner surfaces of the intermediate element, and whose inner surface covers the outer surface of the intermediate element. In particular, the method includes a step of placing a brazing sheet, whose melting temperature is lower than melting temperatures of other elements of the set, over an assembly surface in contact with another assembly surface, and a step of heating, by a furnace, a set including the outer or inner walls and the intermediate element between which is interposed a brazing sheet so as to fix the outer or inner wall by brazing on the intermediate element.