The Mikoyan-Gurevich MiG-3 () is a Soviet fighter-interceptor used during World War II. It was a development of the MiG-1 by the OKO (opytno-konstruktorskij otdel — Experimental Design Department) of Zavod (Factory) No. 1 in Moscow to remedy problems found during the MiG-1's development and operations. It replaced the MiG-1 on the production line at Factory No. 1 on 20 December 1940 and was built in large numbers during 1941 before Factory No. 1 was converted to build the Ilyushin Il-2.
On 22 June 1941, at the beginning of Operation Barbarossa, some 981 were in service with the Soviet Air Forces (VVS), the Soviet Air Defence Forces (PVO) and Soviet Naval Aviation. The MiG-3 was difficult to fly in peacetime and much more so in combat. Originally designed as a high-altitude fighter-interceptor, combat over the Eastern Front was generally at lower altitudes, where it was inferior to the German Messerschmitt Bf 109 as well as most of its Soviet contemporaries. It was also pressed into service as a fighter-bomber during the autumn of 1941 but it was equally unsuited for this. The losses suffered in combat were very high, in percentage the highest among all the VVS fighters, with 1,432 shot down. The survivors were concentrated in the PVO, where its disadvantages mattered less, the last being withdrawn from service before the end of the war.
Development
The large number of defects noted during flight testing of the MiG-1 forced Mikoyan and Gurevich to make a number of modifications to the design. Testing was done on a full-size aircraft in the T-1 wind tunnel belonging to the Central Aero and Hydrodynamics Institute (TsAGI) to evaluate the problems and their proposed solutions. The first aircraft to see all of these changes applied was the fourth prototype of the I-200. It first flew on 29 October 1940 and was approved for production after passing its State acceptance trials. The first MiG-3, as the improved aircraft was named on 9 December, was completed on 20 December 1940 and another 20 were delivered by the end of the year.
These changes included: The engine was moved forward 100 mm (4 in) to improve longitudinal stability. A new water radiator (OP-310) was fitted The first two modifications allowed an additional fuel tank to be fitted underneath the pilot's seat. The outer wing panel dihedral was increased by one degree to increase lateral stability. An additional oil tank was mounted under the engine. Piping was fitted to use cooled inert exhaust gasses in the fuel tanks to reduce the chance of fire. The back of the pilot's seat was armored with an plate (increased to in later models). The supercharger intakes were streamlined. The main landing gear was strengthened and the size of the main wheels was increased to 650 x 200 mm (25.5 x 7.87 in). The canopy glazing was extended aft to improve the view to the rear which allowed for the installation of a shelf behind the pilot for an RSI-1 radio (later upgraded to an RSI-4). The instrument panel layout was improved and a PBP-1A gunsight replaced the original PBP-1. Ammunition for the ShKAS guns was increased to 750 rounds per gun. Two additional underwing hardpoints were added to carry up to 220 kg (485 lb) of bombs, spray containers or RS-82 rockets.
State acceptance testing of two production aircraft was conducted between 27 January and 26 February 1941. They were found to be over heavier than the MiG-1, which reduced maneuverability and field performance. Time to decreased by over a minute and the service ceiling proved to be less. The MiG-3 was faster at sea level and at altitude. While the ranges reached by both aircraft were farther than that of the older aircraft, they were still less than the required. Mikoyan and Gurevich protested against the range results as their calculations showed that the MiG-3 could reach based on a specific fuel consumption (SFC) of 0.46 kg/km (1.64 lb/mile). During the State acceptance trials the SFC was 0.48 kg/km (1.71 lb/mile) but the operational trials conducted earlier showed a SFC of 0.38 kg/km (1.35 lb/mile). They blamed the deficiency on a failure to use an altitude correction and that the engines had not been properly adjusted. They went as far as arranging for two more flights between Leningrad and Moscow to prove that the MiG-3 could fly 1,000 km (621 mi). Two production aircraft were flown on ranges of and , flying at 90% of maximum speed and at an altitude of , contradicting the report of the NII VVS (Naoochno-Issledovatel'skiy Institoot Voyenno-Vozdooshnykh Seel—Air Force Scientific Test Institute).