Abstract: A noise attenuation panel 10 for an aero engine environment comprises a first cellular component part 121 which has wall portions which extend from the front face to the rear face and which provide bounding surfaces for an array of cells 15 and a second cellular component part 122 in the form of an open-celled structure having a multiplicity of the intercommunicating cells obtained by aggregation of particulate material or by the displacement of material by a dispersion or like technique. A backing component part 11 is secured to the rear face of the second cellular component part 121, the front face of which is secured to the rear face of the first cellular component part and a facing component part 14 is secured to the front face of the first cellular component part. In an alternative form, the positions of the cellular component parts 121, 122 are interchanged.

Abstract: An aircraft structural component comprising a forward compartment formed by a forward bulkhead and a skin structure which extends forwardly of the forward bulkhead and which has an outer surface, and a rear compartment formed between the forward bulkhead and a rear bulkhead. A supply duct extends through the rear compartment and into the forward compartment for the delivery thereto of pressurized hot gases for distribution over the inner surface of the skin structure. A protective shroud duct surrounds the supply duct, extends from the rear bulkhead to the forward bulkhead and forms an annular space between the protective shroud duct and the supply duct. The annular space is closed off at its rear end at the rear bulkhead and throughout its length within the rear compartment by the protective shroud duct and is open at its forward end for gaseous communication with the forward compartment. A discharge duct extends from the forward compartment to atmosphere.

Abstract: Fatigue, the phenomenon of structural or system failure, caused by repeated excitations from high frequency noise or vibration levels, can occur without warning in inlet cowls, fan ducts and thrust reverser translating cowls of aero engines. In modern day nacelle and fan duct design, the use composite structures predominates and a composite structural component is provided which does not suffer or does not suffer the same extent from such potential fatigue problems. The structural component has a front face for exposure to fatigue generating energy and includes a composite frontal region which includes the front face and which comprises a matrix and a high fatigue-strength metal or metal alloy mesh embodied within the matrix or partially embodied within it at the front face. The matrix is in sheet form and comprises or includes a synthetic resin.

Abstract: A missile is housed in a launcher from which it is launched by efflux gases from a thrust motor of the missile. A closure device is secured by retaining screws in a position in which it closes off the rear end of the missile and embodies a thrust generating cartridge which is fired to propel the device clear of the rear end of the missile. The closure device comprises a demand cap and base plate and the cartridge generates thrust first to release the cap and plate from the screws and then to displace the domed cap relative to the base plate to bring them to a disposition in which the momentum of the domed cap is imparted to the complete closure device thereby to propel the cap and the plate together at velocity determined by the motion of the domed cap relative to the base plate.

Abstract: A flap assembly includes a flap member (2) located at the trailing edge of an aircraft wing (4). A bracket (12) extends down from the flap member (2), and a mounting arm (8) extends rearwardly from the lower surface of the wing. Two link arms (14 and 16) are pivotally mounted at their upper ends (18 and 20) to the mounting arm (8), and at their lower ends (22 and 24) to the bracket (12). The flap member (2) is moved between its stowed and its downwardly extended positions by an actuating mechanism (26) which is mounted on the aircraft wing (4), and connected either to the flap member (2) or to the bracket (12). The actuating mechanism (26) may be of either a linear or a rotary type.

Abstract: A ducted fan turbine engine (2) includes an inner discharge nozzle (18) and an outer discharge nozzle (8) surrounding the inner discharge nozzle. The engine (2) is mounted on an aircraft wing by a pylon. The rear part of this pylon supports rollers which run in guide rails (36) which extend rearwardly along the upper portion of the outer discharge nozzle (8). The outer discharge nozzle (8) is secured in its forward operational position adjacent the engine nacelle by bolting support fittings (38) to the pylon. To remove the remainder of the engine, the support fittings (38) are unbolted from the pylon, a locating device (28) is released from the engine thrust reverser structure, and the outer discharge nozzle (8) and a primary nozzle fairing (22) are rolled rearwardly to a park position. The remainder of the engine can then be removed downwardly from the aircraft.

Abstract: A method and apparatus for moulding a fluid settable material. The apparatus includes male and female mould halves defining between them a mould cavity having an inlet thereto for the introduction of a fluid settable material; between the male and female mould halves of the cavity a seal can be interposed to seal the mould cavity from the atmosphere. At least one vacuum outlet from a mould half leads via an isolation valve to a vacuum source.

Abstract: An optical aiming device comprising optical elements providing a primary optical path by which a field of view is presented to an observer and a secondary optical assembly providing two stabilized secondary optical paths for projecting a stabilized aiming mark into the field of view and for projecting from the device a stabilized optical aiming beam. The secondary optical assembly comprises a reflector by which the secondary optical paths are stabilized, the reflector being mounted in a gimbal for rotation about a first axis and the gimbal being mounted for rotation about a second axis perpendicular to the first axis, and the assembly further comprising stabilizing actuator means operative to move the reflector and the gimbal about the two axes of rotation to maintain the reflector stabilized against movement within predetermined limits of the device about the two axes.

Abstract: A canopy assembly for an aircraft includes a forward canopy panel and a rear canopy panel carried by a support frame. The canopy panels are mounted on the support frame by buttstraps. The bottom edges of the forward canopy panel and the rear canopy panel are set in a bed of sealing compound. A bed of a release agent prevents adhesion between the front part of the forward canopy panel and the bed.The canopy panels are attached to one another at a central region by internal and external buttstraps. The adjacent parts of the panels are contained in beds of sealing compound, and a release agent is applied to said adjacent parts. The rear edge of the canopy panel and the front edge of the canopy panel are scalloped adjacent each clamping bolt.In the event of a birdstrike the forward canopy panel deforms and moves locally rearwardly with respect to the aircraft fuselage. The central buttstraps may also move locally rearwardly with respect to the aircraft fuselage and rear panel.

Abstract: Moldings (41) of fibre/resin matrix composite material are vacuum bag molded "net-to-size" by providing periphery elements (20-22) on the molding face (11) of the tooling (10) and allowing them to slide on the molding face during curing of the molding. Buttstrap edges (FIG. 3) can be provided in this way, on the molding, as an integral part of the molding process.

Abstract: An ultrasonic scanning system for testing large curved components of fiber/resin matrix composite material, the system ultrasonically testing these components with water jet probes caliper-mounted on the working arm of an industrial robot. The computer reads CAD data appertaining to the component, transfers it to robot-compatible form and delivers it on demand to the robot computer. The computer also reads the data output from the probe and reconciles it with the CAD data to yield as an output a quality map of the component. Instantaneous probe position on the surface of the work piece is computed from data on the starting position of the scanning movement of the probe, and the scanning velocity of the probe.

Abstract: Damage to the skin of the annular cowl (11) of the intake duct of a turbo-fan engine of an aircraft by exhausting on to it of hot air used within the cowl for de-icing its leading edge (10) is avoided by channelling spent air through an exhaust duct (15) to an exhaust aperture (21) in the surface of the cowl, and providing a heat shield (23) in the skin downstream of the exhaust aperture (21).

Abstract: A laser guidance beam (30) for beam-riding aerial missiles is reflected at a stabilized mirror (M) to stabilize its position in space. A target (T) is viewed by an operator in a field of view (22) which also contains an aiming mark (A) stabilized by the mirror (M). A joystick (27) is used to generate signals for rotating the mirror (M) to bring the stabilized aiming mark (A) into superposition with the target, whereby the guidance beam (30) is also superposed on the target. Separate mirrors can be used for stabilization in pitch and yaw (FIG. 8). Different mirror elements on a single mirror unit, with the elements separated by a baffle, can be used to eliminate the risk of laser radiation of the guidance beam from entering the eye of the operator.

Abstract: A variety (FIG. 4) of aero engines (30) can be rear-loaded into an aircraft cargo bay (10) with precision and safety and minimal clearance with the sides of the bay (10) by installing a roller conveyor trackway (20,22) along two seat rails (12,14) running the length of the bay (10) and its bottom-hinged rear-loading ramp (15). A ground trailer (33) carrying the engine (30) on its yoke (31) is coupled to a dolly (37) running on the trackway (20,22) and the yoke (31) transferred from rails (32) on the trailer (33) to rails (36) on the dolly (37). The dolly (37) is then winched (27) along the trackway into the bay (10) where it is made secure for flight of the aircraft. The dolly (37) can be dismantled when not in use and the trackway (when installed) is useful when pallets are to be transported.

Abstract: A miniature gyroscope having a gas-turbine reaction rotor of dumb-bell form which comprises a pair of masses (62,63) one spaced from the other at opposite ends of a shaft, and an inner gimbal (61) which extends into the space between the two masses and there provides a rotational mounting for the rotor, and means (42) for feeding to the rotor, through the space between the pair of rotor masses, gas to be discharged from the rotor to cause it to spin.

Abstract: The duct (16) which delivers hot air (F) to the inside surface of the leading edge of a turbo-fan inlet cowl, for de-icing of the leading edge (11), is made double-walled (16,21) in order to safeguard from overheating the materials from which the cowl is constructed in the event of rupture of the duct. Preferably the flow of hot air in the outer duct blows open a hinged door (26) in the skin (10) of the cowl to provide a visual indication of the rupture of the inner duct. The outer duct can be made narrow enough to maintain working pressure in the inner duct after rupture.