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 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 composite component is made up by laying pre-forms one on top of the other and tacking the pre-forms together at spaced, discrete locations by blind stitches which tack an upper pre-form layer to the one beneath it, using a stitching head. The stitching head 16 includes a curved needle 18 reciprocally movable in one plane and a looper 30 reciprocally movable in a transverse plane. In use the looper catches the thread from the needle as it emerges from the material and draws it into a loop around the next entry point for the needle.

Abstract: A navigational system for determining the relative position of two objects, which comprises projector means for projecting an information field to be at least partially incident on both said objects, receiver means associated with at least one of said objects for detecting the information field incident on said two objects, and means responsive to the receiver means to determine the relative position of said objects.

Abstract: A dioptric lens system comprises a plurality of lenses and a rear diaphragm functioning as an aperture diaphragm. An overall length in the order of the focal distance is obtained by the features that the object side surface of the object side lens comprises an aspherical component and that the intermediate and image side lenses are closely adjacent.

Abstract: An airborne body (1) towed behind an aircraft (2) is manoeuvrable around the flight path of the aircraft in order to intercept or collide with an incoming threat and thus protect the aircraft either by directly damaging the threat or causing it to fuze prematurely. Means for steering the body may take the form of control lines (3a, 3b, 3c) operated by winches (8).

Abstract: Aiming system for firearms of the type for use when a target is obscured for example by darkness or camouflage include a sighting arrangement which comprises an imaging device of sufficiently small size to be carried on the firearm. These imaging devices consequently have small apertures and low resolution and are therefore of limited value. The aiming system disclosed herein has an imaging device remote from the firearm which forms a background image of a given field-of-view, the image being displayed on a screen. The system includes a second imaging device carried by the firearm and having a smaller field-of-view corresponding to the line-of-sight of the firearm. The images produced by both imaging devices are correlated by a correlator and a sight-mark is generated in the background image to indicate the line-of-sight of the firearm when correlation is obtained.

Abstract: The invention provides work piece support apparatus for supporting resilient sheet material during a machining operation, e.g., routing, in which the support apparatus includes hydrostatic clamping means comprising perforated support pads positioned each side of the resilient material and connected to a fluid supply. By this arrangement a fluid layer under relatively high pressure is interposed between each pad and the adjacent region of sheet material which is thus fluid pressure supported in the immediate vicinity of the routing tool throughout the machining process. The invention beneficially provides a routing machine including the work piece support apparatus in which the work piece is positioned in a generally vertical plane and the routing tool is mounted about a generally horizontal axis.

Abstract: An arrangement for detecting and isolating leaks in a high temperature ducted flow system in which the fluid flow ducts are contained within duct insulation means which define an insulating air space around the ducts. The arrangement is configured such that in the event of a fractured or leaking duct, the leaking flow is contained within the insulating air space and constrained to flow to one pre-determined end of the duct system where it is ejected through a fluid outlet opening positioned in close proximity to leak sensing means. By this arrangement the leakage flow is cause to impinge on the leak sensing means enabling the leaking system to be effectively isolated.

Abstract: Rotating surveillance systems of the type which detect a moving object within a field-of-view and provide a representative image of the object may suffer from limited sensitivity when having a wide coverage. The system described herein detects and provides an identifiable image of a moving object within its field-of-view by forming an image of the object on a charge-coupled device and determining the rate of relative movement between the image and the device and hence using the rate of relative movement to provide signals which hold the image of the moving object substantially stationary with respect to the imaging sites of the charge-coupled device to produce a generally sharp image of the object compared with the background.

Abstract: Signal discriminating apparatus for receiving a plurality of analog signals and for selecting therefrom a particular signal of which the value bears some predetermined relationship to the values of the other signals, for example the median value signal, comprises a sequence of extreme value selector circuits each operable for receiving the signals or a sub-set thereof and for picking out an extreme-value one of the received signals, and disabling means for causing all but the first selector circuit in the sequence to be non-responsive to signal(s) selected by previous selector circuits.

Abstract: Apparatus for laying a filament includes a tool 10 moveable to follow a predetermined path, the tool comprising a storage chamber 12, 12', opposed outlets 30, 28, 16 and 116, 128 and clamp arrangements 19, 119 associated therewith. In use, filament is fed via outlet 30, 28, 16 through the chamber 12, 12' to protrude from outlet 116, 128. Clamp 119 is actuated and continued feeding causes the filament to be stored. Feeding is continued until the other end of the filament protrudes from outlet 116, 128. The tool is operable to define a gap through which filament may be bodily laterally withdrawn, once its free ends have been attached to respective attachment points.