Polikarpov Po-2

The Polikarpov Po-2 (also U-2 before 1944, for its initial uchebnyy, 'training', role as a flight instruction aircraft) was an all-weather multirole Soviet biplane, nicknamed Kukuruznik (Russian: Кукурузник, NATO reporting name "Mule"). The reliable, uncomplicated design of the Po-2 made it an ideal trainer aircraft, as well as doubling as a low-cost ground attack, aerial reconnaissance, psychological warfare and liaison aircraft during war, proving to be one of the most versatile light combat types to be built in the Soviet Union. As of 1978, it remained in production for a longer period of time than any other Soviet-era aircraft. It holds the distinction of the only biplane to take down a jet aircraft.

Production figures for Polikarpov U-2 and Po-2 bombers and trainers combined are between 20,000 and 30,000 with production ending as early as 1952. Precise figures are hard to obtain since low-rate production by small repair shops and aero clubs is believed to have continued until 1959.