"In the Soviet Union, during the last months of the Second World War, work on a light universal aeroplane started. The aircraft, the descendant of the popular Po-2, had to be simple in production and in service. In 1944-47 the Aleksandr Yakolev Construction Bureau carried out work on the prototypes of the Yak 10, 13 and 12. The Yak-12 was a four seater, high wing monoplane, powered with the M-11 engine. After swapping the engine to the M-11 FR and some technical modifications, the Yak-12 was mass produced in 1947. Wing slots and flaps enabled a short landing and takeoff, improving low speed flight safety at the same time. Due to these features the aeroplanes were used as trainers, ambulances, parachute carriers and liaison aircraft in the army.
In total, 788 Yak-12's were produced from 1948-1950, including some examples reaching Poland. There they remained in service with the Polish Air Force from 1951, moving to aeroclubs in 1973. One military example was presented at the air show in Wrocław in 1959.
Consecutive versions were equipped with the more powerful AI-14 engine. 1500 Yak A's and M versions as well as the PZL 101 Gawron (crow) were produced at the WSK Okęcie. The displayed aircraft (5013 SP-ASZ) Yak-12, was produced in 1951. From 1951-2 it served with the Polish Air Force and in civil aviation until 1973. In the same year it was given to the museum by the WSK Mielec. It was the longest remaining aircraft in service of that type." (Description taken from the museum website).