Abstract: A power transmission gearbox for rotorcraft for transmitting rotary movement from at least two engine members to a main shaft, wherein the gearbox presents at least two transmission systems for imparting rotary movement to the main shaft, each of the transmission systems including: an inlet shaft designed to be driven in rotation by an engine member; at least two reduction stages presenting different reduction ratios; a first gearwheel connected to the inlet shaft via a declutchable freewheel, the gearwheel meshing with a first toothed wheel secured to an intermediate shaft defining at least a first reduction stage; a second gearwheel connected to the inlet shaft via a simple freewheel, the second gearwheel meshing with a second toothed wheel secured to the intermediate shaft defining the second reduction stage; a main freewheel mounted on the intermediate shaft to rotate a complementary toothed wheel secured to the main shaft; and a clutch mechanism for the declutchable freewheel.

Abstract: An anti-vibratory device with rotary compensation weights includes two sets of two identical rotors with respective eccentric compensation weights, the units being symmetrically disposed in relation to an axis of symmetry and the axes of rotation of the rotors being parallel between themselves and orthogonal in relation to the axis of symmetry; and a rotational drive system for the rotors. Advantageously, the device includes controllable mobile equipment carrying the drive system and being able to slide along the axis of symmetry in order to drive the dephasing of the rotors with eccentric compensation weights associated with the sets.

Abstract: A hydraulic system includes a reservoir for a hydraulic fluid, a pump, a high-pressure line network, a low-pressure line network and operating cylinders each of which can be connected to the high-pressure line network or to the low-pressure line network via control units, each operating cylinder is associated with a local compensation volume element.

Abstract: A rigid hydraulic control shaft for conveying a fluid from a hydraulic valve to a hydraulic chamber of a propeller comprises a main segment. The main segment has a hollow rigid outer tube and a solid rigid inner bar. The inner bar has an outer periphery and at least one longitudinal groove disposed along the outer periphery. The outer periphery is configured to move in rotation and translation with an inner periphery of the outer tube. The main segment is configured to move in rotation and in translation with a piston disposed adjacent to the hydraulic chamber.

Abstract: The present invention relates to a helicopter provided with a main rotor (1) having at least two blades (10, 20), each blade (10, 20) being provided with attachment means (11, 21) attaching it to a hub (2) of the rotor (1). The helicopter is provided with one lift element (12, 22) per blade (10, 20), said lift element being provided with a tiltable tab (19, 29), each lift element (12, 22) being mechanically connected to a single blade (10, 20) to vary the pitch of said single blade (10, 20).

Abstract: A helicopter is fitted with a main rotor (1) having at least two blades (10, 20), each blade (10, 20) being provided with attachment elements (11, 21) for attaching it to a hub (2) of the rotor (1). The rotor is also fitted with one lift element (12, 22) per blade (10, 20), each lift element (12, 22) being mechanically linked to a single blade (10, 20) to vary the pitch of the single blade (10, 20) with which the lift element (12, 22) is linked.

Abstract: A rotorcraft rotor blade (1) includes at least one tiltable trailing-edge flap (5), the flap (5) being suitable for pivoting about a virtual hinge axis (Y?) extending substantially along the span of the blade (1) and of the flap (5). The blade (1) is remarkable in that it is provided with at least one main ball joint (30) provided with an inner cage (32) together with a first pin (31) and an outer cage (33), the front portion (33?) of the outer cage (33) of the main ball joint (30) being connected to a linear actuator (10, 10?) arranged in the blade (1) and serving to pivot the flap (5), the first pin (31) of the main ball joint (30) being substantially perpendicular to the virtual hinge axis (Y?) about which the flap (5) pivots.

Abstract: A device for contactless electrical power transmission in a system including at least one stationary and one moving part, power being transmitted between the at least one stationary part and the at least one moving part includes an inductive transformer including a primary winding disposed on the stationary part and a secondary winding disposed on the moving part, the inductive transformer bridging an isolating point between the stationary part and the moving part. The device also includes a frequency generator having a series-resonant circuit capacitor connected to the primary winding and at least one actuator control element connected to the secondary winding and including a matrix arrangement of a plurality of switchable power semiconductors. At least portions of the inductive transformer, frequency generator and at least one actuator control element are disposed in an area of a rotor shaft and a rotor head of a rotary-wing aircraft.

Abstract: An aircraft door arrangement, especially for an airplane, comprising a door; a door frame; a support arm with a pivoting axis on the door side, on which the door is mounted so as to swivel, and a pivoting axis on the frame side, on which the support arm is mounted so as to swivel on the door frame, whereby at least the pivoting axis on the door side is defined by two articulated joints positioned at a distance from each other in the vertical direction of the support arm, of which articulated joints at least one articulated joint has two bearings positioned at a distance from each other in the vertical direction; a pivoting drive that is arranged in the area of the support arm on the door side and that serves to swivel the door; and a driven element that is coupled to the pivoting drive and to the door and that transmits an actuating movement of the pivoting drive to the door.

Abstract: An undercarriage (2) for an aircraft (1) includes anti-crash elements that are specific to a second stage of a crash after the end of a first stage. The undercarriage includes: a device for blocking a retraction actuator (6); a device for retaining the actuator (6) functionally separated from a landing gear leg (9); and a device for applying controlled braking to the pivoting of the leg (9) by irreversible lengthening of a deformable member (25).

Abstract: A rotorcraft blade is provided with a rigid attachment filler (1) and with a spar (40) that extends from a root (51) of the blade to a free end (52) of the blade, the attachment filler (1) having top, bottom, front, rear, left side, and right side faces (2, 3, 4, 5, 7, and 6). The spar (40) then includes a succession of fiber layers (31, 32, 33) that hold the attachment filler (1) captive at the root (51) of the blade, the spar (40) being secured to the top, bottom, front, rear, and left side faces (2, 3, 4, 5, and 7) of the attachment filler (1).

Abstract: Aerodynamic high-performance profile (10), in which, to force a turbulent flow of the boundary layer away from the bottom side (12), a transition strip (16), which extends over the entire length of the rear edge, is situated in direct proximity to the rear edge (15).

Abstract: The composite structure for protecting a main core comprises a laminated surface covering having a rigid protective layer and an elastomeric member. A damage tell-tale is inserted between the rigid protective layer and the elastomeric member. The composite structure thus serves both to protect the core and to reveal damage suffered by the core. The structure is applicable, for example, to protecting a structural element of a vehicle such as a helicopter.

Abstract: In order to protect a hinge, an elastomer confinement structure is provided presenting: upstream and downstream openings; a static cap; an upstream collar; and a hinge bellows. Each opening has a ring for rigidly anchoring to a downstream member of the hinge, and each opening has a ring acting as a rigid receiver. The collar is movable and releasably secured by resilient fastening inspection means.

Abstract: A process and device for estimating the vertical speed of a rotary wing aircraft may include integrating the sum of: (1) a first component corresponding to a vertical acceleration measurement and (2) a second component obtained from the difference between: (a) a first value incorporating a barometric measurement and (b) a second value incorporating a previous estimation of the vertical speed. The second component is derived from the difference between the first and second values by clipping this difference to eliminate, as appropriate, the part of the difference which is greater, in absolute value, than a predetermined value.

Abstract: The present invention relates to an autopilot system for a rotary wing aircraft operating relative to at least two pilot axes, which system comprises, for each of the two axes, at least one servo-control relationship providing a respective initial control instruction, with the two relationships having a common target; the system includes combination means (36) for providing a series of control instructions by combining the two initial control instructions (UCV, UTV).

Abstract: The thermal detection and visual alarm unit includes a plurality of first expansion thermal detectors (17) with normally closed contacts that are connected in series with a first lamp (15) to form a first two-terminal circuit (21, 23), a plurality of second expansion thermal detectors (18) with normally open contacts connected in parallel, a second lamp (16) connected in series with the second thermal detectors to form a second two-terminal circuit (22, 24), the first and second thermal detectors forming a plurality of cells (19) each combining a first detector and a second detector having respective contact-opening or contact-closing temperatures that are substantially equal, each of the first and second two-terminal circuits being arranged for connection to the terminals of an electrical power supply (12).

Abstract: A system (20) on board or suitable for use on board an aircraft to define an aircraft track having a plurality of segments, the system includes a display unit (10) arranged to display an image (11) containing a representation of the footprint of a segment (S, S1, S2) in a plane or level; an analog input member (17) for inputting altitude data (A) into a computer (13) connected to the display unit; and a calculation program or module arranged to determine a representation (C1, C2, PR1, PR2) of relief that is dangerous for a flight altitude equal to the value of the altitude data (A), and to superimpose (or include) the representation on (in) the image (11).

Abstract: A rotor blade comprises an inner rotor blade root area, a rotor blade main area disposed adjacent to the inner rotor blade root area along a length of the rotor blade and having an aerodynamically effective rotor blade profile, the profile including a nose area and a rear edge area, and a rotor blade tip disposed adjacent to the rotor blade main area along the length of the rotor blade. The rotor blade tip is configured to be deformable relative to the rotor blade main area and is operatively connected to a first actuator device. The first actuator device is configured to initiate a vertical movement of the rotor blade tip upwards or downwards relative to the lift direction. The vertical movement starts from a neutral position relative to the rotor blade main area.

Abstract: The present invention relates to an absorbent covering having high damping power, the covering being secured to a structure (20) and being provided with an absorbent layer (10) of elastic material (4). Remarkably, said absorbent layer (10) comprises a dissipater mesh arranged in the elastic material (4) and constituted by a plurality of nodes (2) and of dissipater elements (1), which dissipater elements are advantageously elliptical in shape.