Yakovlev Yak-9U & 9UT

The Yak-9 was originally a development of the Yak-7 fighter of 1941, of which 6,399 were built. It was from the Yak-7D, an experimental variant, that the new model was derived. The need to build a better series of these aircraft was dictated above all by the need to improve their range. The half-wings were partially redesigned, while the pilot's cockpit was moved slightly farther back, and the position of the radiator in the belly was also altered. Production began in the summer of 1942, and the Yak-9 was delivered to the fighter units in October.

The aircraft's intensive career (which began during the battle of Stalingrad) did not prevent it from being updated, a process that initially regarded its armament. In the Yak-9M version, a 12.7 mm machine gun was added to the 20 mm cannon and the original machine guns, while the cargo capacity of the Yak-9B model was exploited to the full, and the aircraft could carry a maximum bomb load of 883 lbs (400 kg). These were followed by the Yak-9T, tested in December 1942 and operational from the beginning of the following year. It was designed for antitank use being armed with the 37 mm Nudelmann-Suranov cannon.

In the 1943 summer a new variant, the Yak-9D, entered service. It had a more powerful engine and was intended for the role of long-range escort fighter. In this aircraft the increase in range, which eventually surpassed 807 miles (1,300 km), was obtained by reducing the defensive armament until it consisted of a 20 mm cannon and a single 12.7 mm caliber machine gun. A further improvement was made in the Yak-9DD, a version derived from it, in which the range was increased to 1,242 miles (2,200 km). These aircraft were mainly used to escort the formations of American bombers which took off from bases in Great Britain to carry out raids on oil fields in Rumania.

The last variant to be built during the war was the Yak-9U, whose prototype took to the air in December 1943. In this model, Yakovlev substantially renewed the airframe, redesigning its entire basic structure (which became all-metal, like its covering) and remarkably improving its aerodynamic lines. In addition, the span and surface area of the wings was increased, while a more powerful engine, the 1,650 hp Klimov M-107A, was adopted. This improved the performance of the aircraft remarkably, increasing the maximum speed of 372 mph (600 km/h) at 11,482 ft (3,500 m) achieved by the Yak-9 D to approximately 434 mph (700 km/h) at 18, 092 ft (5,500 m). It was from this aircraft that the last postwar version, the Yak-9P, was subsequently developed.

In addition to its intensive and lengthy career in the units of the VVS, the Yakovlev Yak-9 also equipped numerous foreign units that had chosen to fight in the Soviet Union. These included the Poles of the 1st Warsaw Fighter Regiment and the French of the Groupe de Chasse Normandie-Niernen, whose pilots chose the Yak-9 after having tried the American Bell P-39 and the Hawker Hurricane. After the war, apart from the Soviet Union, Yak-9 was adopted above all by Bulgaria, Poland, and Yugoslavia.