Abstract: A tool (38) secures and releases a fastening arrangement which includes a first component (10) and a second component (12) which may be releasably fastened together. Fastening is by means of a retention element (34) of shape memory material associated with the second component (12) which is reconfigurable between an open position (first and second components separated) and a closed position (first and second components fastened together). During fastening a closure element (36) urges the retention element (34) from its open position to its closed position. The tool includes a magnetic coil (44) energizable to urge the closure element (36) in a direction to cause the retention element (34) to move from its open to its closed state. The magnetic coil (44), or an additional coil, is also energizable to draw the closure element (36) away from engagement with the retention element (34). A heating coil (45) is provided for heating the retention element (34).

Abstract: A fatigue monitoring system and method is disclosed in which a stream of data relating to the stresses experienced at a plurality of locations over the structure during operation is applied to a neural network trained to remove data stream values deemed to be in error. The data from the neural network is then processed to determine the fatigue life.

Abstract: A fastening arrangement (14) comprises a shank (16) with a head (18) retained in a first component (10). The other end (25) of the shank is tapered or of other non-constant cross section and terminates in a domed portion (26). A second part of the fastening arrangement includes a collar (34) of shape memory metal material, which may be swaged to engage and retain the domed portion (26) by a magnetized pressure ring (36), which is applied by applying a strong magnetic field. To release the fastening, the pressure ring is released by the application of a magnetic field and the collar (34) is then heated so that it reverts to an open position.

Abstract: An aircraft carrier is provided with an airflow deflector such as flap 26, an inflatable flap 26 or an airjet curtain such that air passing along the flight deck is provided with an upward component of velocity, thereby to provide an upwash in the airwake behind the aircraft carrier. The upwash persists for a reasonable length downstream of the aircraft carrier and means that, for a given spatial attitude, the angle of attack of the aircraft relative to the airstream is increased. This means that the aircraft may be flown at a reasonably high angle of attack to the airstream on a landing approach without sacrificing the pilot's view of the deck. In addition, the increased angle of attack may be used to facilitate a flare maneuver.

Abstract: A deployment mechanism for moving an aircraft wing leading edge slat (2) or trailing edge flap (4) relative to a main airfoil (1) is provided. The mechanism includes an I-section support beam (6) extending between the main airfoil (1) and the slat (2) or flap (4). The support beam (6) is driven into and out of the main airfoil (1) by a rack and pinion mechanism (22, 23), the rack (22) being disposed along a lower boom (20) of the beam (6) and the beam (6) being supported for rolling contact with the main airfoil (1) by upper and lower straddle rollers (8, 9, 10, 11) positioned between wing leading edge ribs (12, 13). Roller tracks (16, 17, 18) extend along upper and lower booms (19, 20) of the beam with at least one roller track (17, 18) co-extending with the rack (22) adjacent thereto along the beam.

Abstract: A patch of fibre reinforced plastics composite material, a repair kit including such a patch and a method of using such a patch and repair kit are provided. The patch (1) is for attachment to a surface (17) of a fibre reinforced plastics composite structure (11) over an area of damage (10) to the structure. The patch defines an outer surface (3), a bonding surface (4) opposed thereto and a peripheral edge. The patch includes fibre reinforcement and plastics matrix material with the latter being in a final state of hardness. The patch defines a series of small apertures (6) therethrough to allow the passage of gases and other matter through the patch to prevent entrapped air weakening the repair.

Abstract: An aircraft wing, wing assembly and method of reducing drag are provided. The wing asembly includes a main wing portion (10) and a leading edge high lift portion (12). The high lift portion is movable between a retracted position in which it generally merges with the main wing portion and a deployed position forwardly thereof. At least a substantial part of an upper surface (22) of the high lift portion is air permeable or perforated and in flow communication with a suction passage (30) in it. In flight, suction may be applied to the suction passage to reduce the chordwise extent of the turbulent boundary layer over the upper or lower wing surface.

Abstract: An aircraft undercarriage having a drag stay mechanism 22 extending upwardly and rearwardly from a main leg portion of the gear to a part of the aircraft structure. The undercarriage also includes a locking linkage extending between the main leg 10 and the drag stay means 22, being arranged releasably to lock the drag stay members 24, 26 in a substantially in-line position.

Abstract: A strain isolated optical fibre Bragg grating sensor (1) has an optical fibre (2) provided at or adjacent one end (2a) with the Bragg grating (3). An open mouth cap (4) surrounds the fibre end (2a) and region provided with the Bragg grating (3) at a spacing from the fibre, fibre end and Bragg grating. The cap (4) is sealed to the fibre (2) at the open mouth at a side of the grating (3) remote from the fibre end (2a). The cap (4) is made from a low Young's modulus material and is operable to isolate the grating (3) from strain.

Abstract: A method of applying a pattern of stop-off material to a sheet is described, the pattern being stored in a computer memory; the method comprises:(a) placing the sheet (22) on a table (12) that is traversable by a printing head (14) capable of applying jets of fluid from a reservoir onto the underlying sheet,(b) supplying a suspension of stop-off material to the fluid jet reservoir and(c) traversing the printer head (14) with respect to the sheet and(d) so controlling the head that it applies jets of stop-off material to the sheet to form a pattern of stop-off material in accordance with the pattern stored in the said memory.The method finds particular use in applying stop-off material in combined diffusion bonding/superplastic forming fabrication techniques.

Abstract: A method of analysing out of plane deflections in materials under load utilising the projection of a reference grating on to such a material whilst recording information relating to the individual color channels of a color video recording camera thereby providing an imaginery reference grating allowing a conventional Moire fringe analysis of the material.

Abstract: The invention provides an aircraft incorporating a gas turbine engine powerplant wherein at least part of the powerplant forms a part of, or is integrated into, the airframe (i.e. the load-bearing structure of the aircraft) such that the powerplant is subjected to airframe loads (i.e. the main static or aerodynamic loads to which the aircraft is subjected, for example loadings due to the wings, the fin, etc.). A gas turbine powerplant comprising a carcass and a low pressure stage which are designed to be subjected to airframe loads is also discussed.

Abstract: A method of manufacture of an aircraft comprising the manufacture of a range of interconnectable demountable structural modules and assembly of one of a plurality of aircraft variants by the selection and assembly of a pre-determined set of said structural modules.

Abstract: A method of forming an aircraft landing gear strut fairing/debris protector and such a fairing/debris protector are provided. The fairing/debris protector comprises first and second fiber reinforced plastics skin elements (21, 23) with a foamed core (27) between them. The method includes the steps of providing a tool having a tool surface (15, 20) to form each said skin element, forming a lay-up (21, 23) on each said tool surface of fibrous reinforcing material and plastics matrix material and allowing the matrix material at least partly to harden, positioning the tools (8, 13) such that the two skins (21, 23) are supported in their final relationship to each other and introducing a foaming resin (27) between the skins to form a foam core.

Abstract: A composite material construction is provided including a laminate of plies (1, 2, 3, 6, 7) arranged with at least one warp dominated ply (7), alternating with at least one weft dominated ply (1, 2, 3) in a thickness direction and at least two weft dominated plies (1, 2, 3) and at least one warp dominated ply (7) arranged in a width direction in which the width of the at least one warp dominated ply (7) is greater than that of each weft dominated ply (1, 2, 3) and in which the weft dominated plies (1, 2, 3) form a lap joint (4, 5) with each other.

Abstract: A sample (1) is inspected or tested by illumination in which a line of coherent radiation (2) is scanned across the sample (1) with zero shear in the direction of scan. Two laterally displaced images of the sample (1) are generated which are phase stepped by stepping or ramping the phase of one of the two images during each of the line scans so that successive lines are incremented in phase to encode temporally information about the sample in one frame. The encoded information is decoded by running a vertical convolution mask (17) over the encoded frame image.

Abstract: Apparatus for sensing temperature and/or strain in an object includes a broadband light source (1), connector means (2) in the form of an optical circulator or an optical coupler to which at least two substantially identical optical fiber Bragg gratings (4, 5) are connected. Grating (4) receives the broadband light from the connector means (2) and functions as a sensor of temperature and/or strain in an object. Light is reflected back from the grating (4) to the connector means (2) and then passed to the grating (5) which acts as a reference grating through which a light output signal is transmitted to a detector (8) which is conveniently a photodetector. Means are provided for chirping the two gratings (4, 5) at the same bandwidth and the detector (8) measures the intensity of the received light output signal, with the intensity being monotonically related to the change in temperature and/or strain sensed by the grating (4) in the object.

Abstract: A drill or machine tool attachment for use with a vacuum debris extraction system, comprising a bar to which a vacuum extraction nozzle is attached, and a tube slidably mounted on the bar and connected to a drill or machine tool. The nozzle is located on the bar ahead of the drill or machine tool, with the tube biased toward an extended position by at least one spring. The limit of the extended position is set by a locking plate. In use, as the apparatus is offered up to a workpiece to perform a drilling or machining operation, the nozzle makes initial contact with the surface of the workpiece and as the operator applies pressure to the assembly, the drill or machine tool and associated bit or tool moves slideably against the action of the spring thereby guiding the bit or tool through an aperture in the nozzle to contact the workpiece.

Abstract: An attachment for use with a vacuum powered debris removal system, said attachment comprising a debris collection bowl, said bowl having a first aperture through which a material cutting tool may be removably inserted, a second aperture through which a vacuum source may be connected, and a third aperture the open circumferential face of which is designed to lie substantially in contact with a material undergoing a cutting operation, such that in use, as debris is generated by the action of the cutting tool on said material, substantially all debris is collected in said bowl and thereby extracted through the second aperture by the action of the vacuum source.

Abstract: Apparatus for the measurement of out of plane displacements of a panel of material under test comprises; a laser (2) capable of focusing a laser spot (8) onto the surface of the panel (6) of material; a line generating lens (12) for converting the image of the projected laser spot (8) into a focused line (22); and, a photo diode (16) responsive to illumination by laser light and so orientated and disposed in relation to the generated laser line (22) that the out of plane distortions of the panel (16) and resulting movement of the spot (8 to 8') produce a corresponding translation of the generated line (18) across the face of the photo diode (16) and the photo diode (16) produces a recordable output proportional to the out of plane deflection of the panel (6).