The U-2, or Po-2, was a multi-role biplane, created by Nikolay Polikarpov in 1928. The U-2 was designed as a primary civilian trainer and was forgiving and easy to fly.
As designed, the U-2 was a conventional biplane with an air-cooled 100-HP M-11 engine. The aircraft was widely used in agriculture, transport and other roles. Staff plane and ambulance variants also existed, as well as reconnaissance, passenger, floatplane and many other versions.By 1932 a new military trainer variant, U-2VS was designed. It could carry six 8-kg dummy bombs on underwing pylons and had a gunner turret in the rear seat. After the German invasion of the Soviet Union in 1941, many existing U-2s were converted to light night bombers.