Yakovlev Yak-3 - Design and Development

Design and Development

The origins of the Yak-3 went back to 1941 when the I-30 prototype was offered along with the I-26 as an alternative design to the Yak-1. The I-30, powered by a Klimov M-105P engine, was of all-metal construction, using a wing with dihedral on the outer panels. Like the early Yak-1, it had a 20 mm ShVAK cannon firing through the nose spinner and twin 7.62 mm ShKAS machine guns on the fuselage(firing through the propeller), but was also fitted with a ShVAK cannon in each wing. The first of two prototypes was fitted with a slatted wing to improve handling and short-field performance while the second prototype had a wooden wing without slats, in order to simplify production. The second prototype crashed during flight tests and was written off. Although there were plans to put the Yak-3 into production, the scarcity of aviation aluminum and the pressure of the Nazi invasion led to work on the first Yak-3 being abandoned in late fall 1941.

In 1943, Yakovlev designed the Yak-1M which was a smaller and lighter version of the Yak-1. A second Yak-1M prototype was constructed later that year, differing from the first aircraft in plywood instead of fabric covering of the rear fuselage, mastless radio antenna, reflector gunsight and improved armor and engine cooling. The chief test pilot for the project Petr Mikhailovich Stefanovskiy was so impressed with the new aircraft that he recommended that it should completely replace the Yak-1 and Yak-7 with only the Yak-9 retained in production for further work with the Klimov VK-107 engine. The new fighter, designated the Yak-3 entered service in 1944, later than the Yak-9 in spite of the lower designation number.

Production accelerated rapidly, so that by mid-1946, 4,848 had been built.

The designation Yak-3 was also used for other Yakovlev projects - a proposed but never built, heavy twin-engine fighter and the Yakovlev Yak-7A.

The first 197 Yak-3 were armed with a single 20 mm ShVAK cannon and one 12.7 mm UBS machine gun, with subsequent aircraft receiving a second UBS for a weight of fire of 2.72 kg (6.0 lb) per second using high-explosive ammunition. All armament was installed close to the axis of the aircraft (cannon firing through the engine crankshaft and synchronised machine guns in the fuselage above the engine), adding to the accuracy and leaving wings unloaded.