During WWII, the Finnish government repeatedly tried to reduce the impact of the import of military equipment in the technical state of the Finnish forces, since in war conditions such a dependence could be very dangerous. Therefore, in 1942 the Finnish Air Force received an order to provide a specification for a single-seat fighter, and in 1943 the development of prototype had begun. The prototype of the single-seat, single-engine fighter performed its first flight in November 1945, but wasn’t officially accepted in to service. The fighter can develop a maximum speed up to 640 km/h and has decent maneuverability. The armament of the aircraft consists of one 20mm cannon and two 12.7mm machine guns placed under the engine hood.