(19)

(11)

EP 0 070 851 A1

(12)

(43) Date of publication: 09.02.1983 Bulletin 1983/06 (21) Application number: 82900375.0 (22) Date of filing: 04.02.1982

(51) International Patent Classification (IPC):  F41G 7/ 22( . ) G01S 13/ 50( . ) G01S 7/ 03( . ) (86) International application number: PCT/GB1982/000029 (87) International publication number: WO 1982/002776 (19.08.1982 Gazette 1982/20)

(84) Designated Contracting States: DE FR GB (30) Priority: 06.02.1981 GB 19810003690 (71) Applicant: BRITISH AEROSPACE PUBLIC LIMITED COMPANY Farnborough, Hants. GU14 6YU (GB)	(72) Inventor: HOSKING, Michael William Bristol BS12 7QW (GB) (74) Representative: Dowler, Edward Charles, et al  British Aerospace plc Corporate Intellectual Property Department ParkEast, PO Box 87, Farnborough Aerospace Centre Farnborough, Hants GU14 6YU Farnborough, Hants GU14 6YU (GB)