Yak-3U
Rebuilt aircraft with the ASh-82FN radial engine and twin B-20 cannon. Despite the fact the engine was heavier than the previous engines, this version actually weighted less than the standard Yak-3. During a series of test flights started on 12 May 1945, the aircraft achieve a maximum speed of 441 mph (710 km/h) at 20,015 ft (6100 m).