Late in 1941, series production of the MiG-3 was being phased out. The AM-35A engine manufacture was being discontinued as priority having been assigned to the AM-38 for the IL-2 Shturmovik. An attempt was made to adapt the basic airframe to take the 1700hp Shvetsov M-82A 14-cylinder air-cooled radial.
Assigned the Izdeliye designation IKh by the OKB and the provisional official designation I-210, and also referred to unofficially as the MiG-3M-82, the first of five airframes adapted to take the new engine was flown in December 1941.
The M-82A weighed only 20kg more than the AM-35A that it supplanted, but was 38cm wider, a new forward fuselage being necessary to cater for the cross section translation from the circular cowling to the oval centre fuselage. The armament consisted of three 12.7mm guns.
Plans were prepared to initiate IKh production as the MiG-9, but flight test revealed a serious drag problem, severe tail vibration and poor control characteristics. Despite the disappointing results of factory testing, the first aircraft was fitted with yet two more 7.62mm guns and sent to the Kalinin Front. The TsAGI, meanwhile, conducted full-scale wind tunnel testing with one of the IKh aircraft, resulting in development of the I-211.
Engine: 1700hp Shvetsov M-82A 14-cylinder air-cooled radial
Take-off weight: 3382 kg / 7456 lb
Empty weight: 2720 kg / 5997 lb
Wingspan: 10.20 m / 33 ft 6 in
Length: 8.08 m / 26 ft 6 in
Wing area: 17.44 sq.m / 187.72 sq ft
Max. speed: 565 km/h / 351 mph
Range: 1070 km / 665 miles