Mikoyan/Gurevich I-370

During 1953, the MiG OKB launched the design of a single-engined tactical fighter which was to utilise a wing fundamentally similar to that of the twin-engined SM-9, forerunner of the MiG-19, work on which was proceeding in parallel. Officially designated I-370 and assigned the OKB appellation of I-1, the new fighter received a Klimov VK-7 turbojet rated at 3525kg and boosted to 5235kg with afterburning. The prototype was flown for the first time on 16 February 1955, but high speed performance proved disappointing. It was therefore returned to the factory where an uprated VK-7 engine was installed, this having normal maximum and afterburning thrust ratings of 3935kg and 6270kg respectively. With a new wing, the quarter-chord sweepback of which was increased from 55 to 57 deg, the prototype was redesignated I-2 by the OKB. Limited testing of the I-2 was undertaken during which design maximum speed proved unobtainable. A further development of the basic design, the I-3 (I-380), remained unflown owing to the non-delivery of its more powerful VK-3 engine.