|FIGHTER||Virtual Aircraft Museum / USSR / Russia / Mikoyan/Gurevich|
Late in 1942, work was well advanced at the MiG bureau on several aircraft in parallel and referred to as Series "A" prototypes, with which the OKB hoped to fulfil a VP (vysotny perekhvatchik, or high-altitude interceptor) requirement raised earlier in the year. The first of these, the I-220, owed little or nothing to earlier MiG fighters and was of mixed construction, the fuselage being of metal forward of the cockpit and a wooden monocoque aft, and the wings making use of steel main and auxiliary spars with spruce outer panel ribs. The first prototype, which was rolled out of the factory in June 1943 and was first flown during the following month, was initially powered with a low-altitude Mikulin AM-38F engine of 1700hp. Armed with two synchronised 20mm ShVAK cannon, the AM-38Fpowered I-220 achieved speeds of 572km/h at sea level and 630km/h at 7000m, practical ceiling being 9500m. The prototype was then re-engined with a medium-altitude AM-39 affording 1800hp for take-off and flown in January 1944, flight testing continuing until the following August. A second prototype also powered by the AM-39 flew in September 1944, but differed in armament, being the first Soviet fighter to carry four 20mm ShVAK cannon. The following data relate to the second prototype.
The second Series "A" high-altitude fighter and referred to as the 2A, the I-221 was the first of the OKB's fighter prototypes to be fitted with turbo-superchargers. The I-221 was fitted with an AM-39A engine rated at 1700hp for take-off and equipped with a centrifugal compressor and paired TsIAM-developed TK-2B turbo-superchargers which, it was anticipated, would permit maximum power to be maintained to an altitude of 13000m. Although adhering closely in most other respects to the preceding I-220, the I-221 had a rear fuselage of dural construction rather than a wooden monocoque, and the outer wing panels were extended, increasing span by a total of 2.00m. Armament consisted of two synchronised 20mm cannon. The initial flight test took place on 2 December 1943, but the programme came to an abrupt end when, during one of the prototype's early trials, a piston rod fractured, the engine seized and the aircraft crashed.