Abstract: A combat pilot system for an aircraft comprises corresponding combat pilot devices 12, 12′ provided in a runtime module 14 on board the aircraft and a ground-based system training module 16 respectively. The run-time module 12′ is trained using model data generated simulation model 18 as well as feedback data from actual missile firings. The matrix of weights derived from the training routines are then programmed into the neural network in the corresponding combat pilot aid system 12 on board the aircraft so that the runtime module is capable of processing the input data producing the four parameters required for launch of a missile and also a FIRE/NO FIRE indication to the pilot.

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: A flexible assembly cell is made up by providing a regular array of fixed, load supporting pedestals on a concrete sub-floor on a meter matrix throughout the assembly area. Jigs and other assembly equipment required in the area are provided with base fixtures on the same meter matrix and the base fixtures are coupled to the relevant pedestals. The gaps between the pedestals are bridged by rectangular load bearing floor panels to provide a raised floor and to provide an underfloor void for routing of services. Moving a jig would be simply achieved by unplugging the relevant services, relocating the jig to a vacant set of pedestals and reconnecting the services, minimising downtime and recurring costs.

Abstract: A non-contacting capacitive position transducer comprises a stator substrate carrying two electrically conducting inverted wedge regions 14,16 whose width varies inversely in a sensing direction. A moveable pick-off 20 is capacitively coupled to both wedges. The wedges 14,16 are driven with respective distinguishable time varying periodic waveforms, e.g. a sine wave and a cosine wave, and the pick-off voltage at 20 processed to determine the position of the pick-off in the sensing direction. Various configurations of transducer are described, including those of linear, cylindrical and disc form. The pick-off voltage is preferably transferred from the pick-off 20 back to the stator by capacitively coupling the pick-off to a suitably screened pick-off track 36 on the stator.

Abstract: The present invention provides a method of forming and a composite superplastically formed structure comprising a panel (40) provided by at least a pair of superplastically-formed sheets (12, 14, 16, 18), which together form a plurality of cells (42), the panel having an opening (20) therein or therethrough defined by a side wall (48) of a respective one, or side walls (48) of respective ones, of the cells; and an insert plug (38) received in the opening and bonded to the said wall or walls.

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 frequency selective surface includes at least one frequency selective layer (1) made up of an array of electrically conductive elements (2, 2a, 2b), at least one frequency selective layer (3) having an array of non-conductive apertures (4) therethrough overlaying the element layer (1) and a dielectric layer separating the two layers (1, 3). The element layer (1) is complementary in plan view to the aperture layer (3). The element layer (1) and the aperture layer (3) are rotated through 90 degrees in plan with respect to each other and substantially parallel to one another and the element array and the aperture array have the same periodicity.

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.