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The Short SB.5 (serial ''WG768'') was a "highly unorthodox, adjustable wing"〔Staples K.J.〕 British research aircraft designed by Short Brothers in response to the UK Air Ministry requirement ER.100; to provide input for the design of the English Electric P.1 (prototype of the English Electric Lightning) by testing the low speed flight characteristics of various configurations of wing-sweep required for supersonic flight. In addition, the tailplane could be mounted either on top of the fin ("T-tail") or below the fuselage. The tests ultimately confirmed that the original P.1/Lightning design was an effective configuration for high speed flight. ==Design and development== A technical dispute arose between the Royal Aircraft Establishment and the English Electric Company (EEC) as to the optimum configuration for the company's proposed supersonic fighter. A single-seat, mid-winged research machine was built to investigate the low speed handling of the possible configurations. The same basic configuration of the P.1 was incorporated into a simpler testbed that had a fixed undercarriage.〔Winchester 2004, p. 149.〕 Since the SB5 was to test the low-speed flight characteristics, there was no requirement for the undercarriage to be retractable. The contract was awarded to Short Brothers and Harland Ltd of Belfast on 2 August 1950. The machine was designed to allow three different wing sweep angles (50°, 60° and 69°). The sweep adjustment of the wings was made when the aircraft was on the ground. Two different tail plane positions (a) low on the rear fuselage and (b) on top of the fin, were also tested. This requirement was met by the construction of two entirely different rear fuselages and tail units. "The complete rear fuselage, just aft of the engine, was detachable and two alternative rear fuselages were available, one with the tailplane set on top of the fin and the other with the tailplane set below the fuselage. The tailplane angle was adjustable in flight, being electrically actuated." 〔 The wings were made "of plywood, except for light alloy sheeting at the leading and trailing edges,"〔 which restricted the maximimum speed to a modest 350 knots (403 mph; 649 km/h). "Two 20 feet (m ) circumference brake parachutes and one 20 feet (m ) anti-spin parachute ... housed in the rear fuselage above the jet pipe."〔 The flight test report of the SB5 with 60 degrees of sweep and the tailplane in the lower position summarised the design criteria: "At the time of the initial conception of the Short SB5 research aircraft (1949), it was recognised that the trend towards higher angles of sweepback was likely to continue, and this was emphasised by the existence of a design for an operational fighter aircraft, the English Electric P1 (Lightning), which was to have a sweepback of 60°. There was then no flight experience with wings of this amount of sweepback. The SB5 was designed to allow a gradual approach to this configuration, flying initially with 50° sweepback before conversion to 60° when it would resemble, aerodynamically, a seven-eighths scale model of the Lightning. To increase its usefulness as a research vehicle, the aircraft was capable of further modification to operate with 69° of wing sweepback."〔K. J. Staples, Flight Tests on the Short SB5 with 60 °and Low Tailplane Part I- Forces and Moments. p4〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Short SB.5」の詳細全文を読む スポンサード リンク
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