Abstract: An array of reflectors of electromagnetic waves comprising a plurality of trihedral reflectors (10 to 17) arranged about a vertical axis (21) with each reflector orientated about its major axis (22) so that the plane bicseting the angle between two panels (18) is vertical and with adjacent reflectors turned through 60 degrees about their major axes (22) relative to one another, characterised in that the reflectors (10 to 17) are tilted relative to said vertical axis (21) of the array with the adjacent sides (37) of adjacent reflectors diverging so that the major axes (22) of the reflectors are directed from the vertices (19) at the required angles of elevation. Preferably, the horizontal sides (24) of alternate reflectors (14 to 17) at the top terminate closely adjacent to corners of intermediate reflectors (10 to 13). The sides (37) of adjacent reflectors diverge towards the bottom to form triangular gaps (38) therebetween.

Abstract: Auxiliary landing equipment for aircraft which comprises a plurality of inflatable cushions arranged in a predetermined array relative to each other and structure for securing them to the aircraft so that, in an inflated state, the cushions can contact the ground during landing or on take-off and so that, in a deflated state, the equipment can closely follow the contour of the aircraft part to which it is attached.

Abstract: A flexible self-sealing wall member for fuel tanks has a plurality of thin layers of natural or synthetic rubber which are held together at spaced points by lines of drop thread stitching or by spots of adhesive so that the sheets are free to move across each other between the points of connection. The wall may also include a reinforcing fabric web, an outside barrier layer, and an inside barrier layer, both impermeable to fuel held in the tank of which the wall member forms a part. The wall member is self-sealing when penetrated by a projectile because the rubber layers undergo large dynamic elongations and rapidly recover to close up the holes formed, these holes generally being out of alignment.