Alan P Posted August 16, 2009 Share Posted August 16, 2009 BAC TSR.2 Falcon XR227 Digital Fly-by-Wire technology demonstrator, RAE Farnborough 1979 TSR.2 Falcon XR227 had been one of the six pre-production aircraft made for weapons development, and first flew in 1964. It was transferred to RAE Farnborough after the termination of the TSR.2 programme in 1967. In January 1973 it was passed back to BAC for refitting as a fully digital fly-by-wire prototype. Although not the first fully DFBW (Digital Fly By Wire) aircraft to fly (the NASA F-8C Crusader took that accolade in 1972), the large internal volume and avionics stowage bays of the TSR.2 made it much more suitable as a technology demonstrator for the fledgling science of fly-by-wire. Three separate Plessey C20 flight control computers coupled to a Marconi digital processing unit were comfortably fitted into XR227’s large avionics bays. The aircraft also made the first documented use of fibre-optic information transfer using a prototype Ferranti FO module. The design also incorporated the first FADEC full-authority engine control on a pair of modified Rolls Royce Olympus 420 engines. The aircraft later pioneered the sidestick controller used for the Airbus A320 airliner and several other refinements during its long and successful career. XR227 made its first flight in the DFBW configuration from BAC Warton aerodrome on 26th November 1974, going supersonic for the first time on 12th February 1975. The deletion of the offensive and defensive electronics and analogue controls saved over 6,000lb of weight and enabled the modified XR227 to perform to the limits of the design’s envelope. A British speed record of Mach 2.36 (1798mph) was set on 21st August 1975. In addition, XR227 also managed to sustain controlled flight at 67,000ft – over 13,000ft higher than its standard service ceiling. On a test flight from Farnborough in 1978, an initial rate of climb exceeding 55,000ft/min was also recorded during angle-of-attack stability tests. XR227 completed over 900hrs of flight testing, including 250hrs of supersonic flight, much of it above Mach 2. A regular feature at airshows on both sides of the Atlantic, XR227 also participated in a spectacular fly-by with Concorde and the Red Arrows over Buckingham Palace as part of the Queen’s Silver Jubilee celebrations on 4th June 1977. XR227 was transferred back to RAE Farnborough in September 1977, where it received the name “Thunderbird 6” in honour of the popular 1960s TV programme which was enjoying a resurgence at the time, and bore some colourful artwork of a Thunderbirds puppet character (without strings, as the flight controls had no “strings” attached to them!) for the SBAC show in 1979. The aircraft continued to provide extremely valuable data for the development of the next generation of fighter jets. The BAe Systems EAP technology demonstrator, first flown in 1986, and its later offspring the Eurofighter Typhoon, owe their heritage directly to the venerable TSR.2. XR227 continued to fly until 1988, clocking up the highest number of flying hours of any of the nine TSR.2 aircraft completed. It remains the only airworthy example, and is now displayed at the RAF Museum, Duxford. 16 Link to comment Share on other sites More sharing options...
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