Soviet fighter plane developed by Alexander Yakovlev's design bureau, a development of the Yak-1b design. Improvements in the design of the aircraft were aimed at increasing speed and maneuverability. First of all, the aerodynamics of the plane was improved by removing the protruding parts of the plane. The inlet to the oil cooler was changed to two inlets at the base of the wings, the tail wheel was pulled into the fuselage, and the antenna mast was removed. In addition, through a thorough analysis of the airframe structure, it was relieved by 200 kg. The first prototype known as the Yak-1M was made in April 1943. Already the first tests showed a significant improvement in the performance and pilot properties of the aircraft. Mass production, however, was characterized by low performance and, as a result, serial airplanes had reduced performance due to the increase in weight. For this reason, one of the UBS rifles was removed from service. After being introduced to Russian combat units in 1943 and the first meetings with German fighters, German pilots were formally prohibited from engaging in combat with "Yaks without a front radiator and antenna mast". In general, the plane was rated very high, although there were reservations about too weak weapons, which did not allow the first attempt to shoot down a bomber. A total of 25 aircraft of this type were used in the Polish aviation in the period from November 1944 to February 1946. The Yakovlev Yak-3 plane was a single-engine low-wing mixed or all-metal construction (at the end of the war). The wooden hull consisted of a welded steel truss covered with duralumin (in the front and middle part), and plywood covered with cloth (at the back of the hull). Wooden wings with a duralumin girder, covered with plywood. Metal shuttlecocks. Horizontal wooden legs covered with plywood and linen. Control surfaces are covered with duralumin sheet. Classic retractable landing gear. With retractable tail wheel. Technical data: length: 8.5 m, wingspan: 9.2 m, height: 2.39 m, maximum speed: 655 km / h, speed of climb: 18.5 m / s, practical ceiling: 10 700 m, maximum range: 650 km, armament: Fixed - 2 12.7mm Berezie UBS machine guns and 1 20mm SzWAK cannon.