Editing Yakovlev Yak-3 (section)

==Design and development==

The first of two prototypes had a [[Leading edge slats|slatted wing]] to improve handling and short-field performance while the second prototype had a wooden wing without slats in order to simplify production and save [[aluminium]]. 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 aluminium and the pressure of the Nazi invasion led to work on the first Yak-3 being abandoned in late 1941.

In between 1942 and 1943, [[Yakovlev]] built the Yak-1M, a prototype that would ultimately lead to the Yak-3, coupled with the [[VK-105|VK-105PF2]], the latest iteration of the VK-105 engine family, where "P" indicated support for a ''motornaya pushka'' - an autocannon that fires between the engine banks, through the hollow propeller shaft - mounting. It incorporated a wing of similar design but with smaller surface area ({{convert|17.15|to|14.85|m2|ft2|abbr=on}}), and had further aerodynamic refinements, like the new placement of the oil radiator, from the chin to the wing roots (one of the visual differences with the Yak-1, -7, -9). A second Yak-1M (originally meant as a "backup") prototype was constructed later that year, differing from the first aircraft in that it had [[plywood]] instead of fabric covering of the rear fuselage, mastless radio antenna, [[reflector sight|reflector gunsight]] and improved [[Vehicle armour|armour]] and [[engine cooling]].

After the VK-105PF2 engine received a boost from a [[Manifold vacuum|manifold pressure]] of 1050 mmHg to 1100 mmHg, additional tests were needed to determine how it impacted the flight characteristics of the Yak-3. State trials revealed that this boost reduced the time needed to reach {{convert|5000|m|ft|abbr=on}} by 0.1 seconds, the takeoff run by {{convert|15|m|ft|abbr=on}}, altitude gain in a combat loop by {{convert|50|m|ft|abbr=on}}, and speed below {{convert|2400|m|ft|abbr=on}} by {{convert|5|-|6|km/h|mph|abbr=on|0}}.

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 [[Yakovlev Yak-1|Yak-1]] and [[Yakovlev Yak-7|Yak-7]] with only the [[Yakovlev Yak-9|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 [[Yakovlev Yak-9|Yak-9]] despite the lower designation number, and by mid-1946 4,848 had been built.<ref name="Glancey p. 179.">Glancey  2006, p. 179.</ref>

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

The first 197 Yak-3 were lightly armed with a single ''motornaya pushka''-mount {{convert|20|mm|in|abbr=on}} [[ShVAK cannon]] and one {{convert|12.7|mm|in|abbr=on}} [[Berezin UB|UBS]] synchronized [[machine gun]], with subsequent aircraft receiving a second UBS for a weight of fire of {{convert|2.72|kg|lb|abbr=on}} per second using high-explosive ammunition. All armament was installed close to the axis of the aircraft with a cannon mounted in the engine "vee" firing through the propeller boss, synchronised machine guns in the fuselage, helping accuracy and leaving wings unloaded.