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The Yakovlev Yak-140 was a Soviet prototype light-weight supersonic fighter developed during the 1950s. It was completed in 1954, but was forbidden to enter flight testing and was canceled in 1956. ==Development== The Yak-140 was developed around the Mikulin AM-11 turbojet (rated at thrust dry and with afterburner) to meet a specification issued in 1953 requiring a supersonic fighter with a maximum speed of and a range of . It was to be armed with three cannon with 75 rounds per gun and was to be capable of carrying air-to-ground rockets as well as of bombs. Its fully loaded weight was to be and it was to be ready to be submitted for State acceptance trials in March 1955.〔Gordon, p. 190〕 It had a circular-section semi-monocoque fuselage with a nose air intake. A range-only radar was fitted in the conical inlet cone of the air intake. The wings had a sweep angle of 55° at quarterchord. Two wing fences were fitted on the upper surface of each wing. The horizontal stabilizer was midway down the rear fuselage and two air brakes were fitted on its underside. The cockpit canopy was faired into the spine that ran the length of the top of the fuselage. The tandem undercarriage had a single wheel on the forward unit and twin-wheels on the main unit with outrigger struts that retracted aft into wingtip fairings.〔Gunston, p. 488〕 The aircraft's State acceptance trials were delayed until the first quarter of 1956 for lack of a flight-ready AM-11 engine, but this did not help and it had be adapted to use a less powerful Mikulin AM-9D engine with only of dry thrust. The gun armament was reduced to only two Nudelman-Rikhter NR-23 guns with 75 rounds per gun in compensation, but the estimated speed dropped by about regardless. This was deemed to be acceptable as it suffice to begin flight-testing.〔 The prototype was completed in December 1954 and it passed all the necessary ground tests by 10 February 1955 when it was cleared to begin flight trials. However, MAP (''Ministerstvo Aviatsionnoy Promyshlennosti''—the Ministry of Aviation Industry) denied Yakovlev authorization to begin flight tests as it favored competing designs from Sukhoi and Mikoyan-Gurevich. A Council of Ministers directive was issued on 28 March 1956 to terminate the program and the corresponding MAP order followed on 6 April.〔 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「Yakovlev Yak-140」の詳細全文を読む スポンサード リンク
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