The Mig 3 is a further development of the MiG-1 with only minor differences (but quite different in handling). To cure poor spin performance of the MiG-1, automatic slats were added. No other country had such a high-speed high-altitude interceptor in service, and even the Luftwaffe was taken by surprise when some of its high-altitude reconnaissance planes were lost to unseen Soviet fighters. The MiG-3 was almost perfectly suited for their designated role, but the well known events of 1941 forced pilots to engage the Mig 3 as a replacement for conventional fighters or even ground attackers. It was a forced misuse of a good high altitude interceptor with limitations in low altitude performance. At the beginning of the Great Patriotic War (what was WWII for Soviet people) many MiG pilots rammed German bombers after running out of ammunition - often the order was "to stop bombers by any means". All were equipped with protected fuel tanks, with neutral gas filling. This somewhat 'cushioned' other low altitude deficiencies. The Soviets built 3,322 Mig 3 variants. The aircraft was in service almost until the end of the war, thanks to exceptionally easy maintenance, reparability and part compatibility. Generally, a flying Mig 3 could be assembled in the field from two or three irreparable aircraft giving it tremendous longevity.