Yak-9, Yakovlev


The Yakovlev Yak-9 was the definitive development of the Yak-1 series. The Yak-9 was a development of the Yak-7 with metal wing spars. It was built in long-range fighter, ground attack and trainer versions. The Yak-9T carried a 37mm cannon, and the Yak-9B had, despite its small size, an internal bomb bay. From mid-1944 onwards the Yak-9 was the numerically most important Soviet fighter. During WWII 14579 were built; production continued until 1948 and totalled 16769 aircraft.

Type: Yak-9D
Country : Russia
Function: fighter
Year: 1942
Crew: 1
Engines: 1 * 1360hp Klimov VK-105PF-3
Length: 8.55 m
Height: 3.00 m
Wing Span: 9.74 m
Wing Area: 17.15 m2
Wing loading: 181 kg/m2
Empty Weight: 2350 kg
Max. Weight: 3120 kg
Speed: 602 km/h
Rate of climb: 13.7 m/s
Ceiling: 10600 m
Range: 1360 km
Armament: 1 x 20 mm ShVAK cannon (120 rounds of ammunition) 1 * 12.7 mm machine gun (200 rounds)

Yak-9 design and performance

Yakovlev's Yak-9 was a development of the line of Russian fighters that started with the Yak-1, evolved into the Yak-3, and reached maturity with the Yak-9. The Yak-9 was the mainstay of the Soviet Air Force in the middle and late years of World War II, and was produced in greater numbers than any other Soviet fighter. By the middle of 1944 there were more Yak-9s in service than all other Soviet fighters combined. Like other Russian fighters, it was designed for mass production and durability. It offered little in new technology and, due to chronic Soviet shortages, incorporated a minimum of scarce strategic materials, especially in the earlier models. Soviet fighters of the era, including the Yak-9, were designed to achieve numerical rather than technical superiority.

Nevertheless, it could be a formidable fighter, particularly at low altitude and when Soviet pilots had numerical superiority over the Luftwaffe fighters opposing them, which was a common scenario on the Eastern Front. The Yak-9 was not a great fighter one-on-one in the air superiority role, it was just 'good enough'.

The Yak-9 had an excellent (small) sustained turning diameter at low speeds, which allowed it to turn inside of the German fighters it faced. It could also turn inside of most of the famous American fighters of the war, including the P-38, P-47, and P-51. The Bf 109 had a slightly superior turn rate, but a larger turning diameter. This means that a Yak-9 could usually get inside of an opponent in a sustained turn. By all reports it was also a durable fighter, capable of absorbing a lot of battle damage and still making it home. It was also a successful ground attack fighter, and some variants were specialized for that role.

On the debit side, compared to most other contemporary fighters, the Yak-9 is relatively slow, climbs poorly, and performs poorly at high altitude. It was a short-range fighter (combat radius of most models was similar to that of the Bf 109), and not particularly well armed.

The Yak-9 entered service in October 1942, and subsequent versions remained in service with the Soviet Air Force and later its client states (including Poland, Hungary, China, Yugoslavia, and Bulgaria), into the early 1950's.

The Yak-9 first made its presence felt during the Battle of Stalingrad in early 1942. The first production Yak-9s had wooden wings with metal spars, and a mixed construction fuselage with a molded plywood skin. Power came from a liquid cooled "Vee" engine, the M-105PF, rated at approximately 1,100 hp. Armament consisted of one 20mm cannon firing through the center of the propeller boss, and one 12.7mm (.50 caliber) machine gun firing through the engine cowling. The Yak-9 could also carry six rockets or two 220-pound bombs.

Yak-9 Versions

By February of 1943, the Yak-9M was in production. This standard version was armed with one 20mm cannon and two .50 cal. machine guns, all concentrated in the nose of the airplane. The wingspan was reduced, and the ribs were made of lightweight duralumin. The engine was upgraded to the 1,240 hp. M-105PF-3. The Yak-9MPVO was a night fighter variant equipped with a searchlight and a radio compass.

The Yak-9T was an anti-armor, ground attack version that entered service early in 1943. It was usually armed with a 32mm or 37mm cannon and had wing racks for 5.5 pound anti-personnel bomblets in special containers. Later in 1943 came the limited production Yak-9K, which featured a 45mm cannon. The Yak-9B was another limited production version, this time a light bomber variant with internal stowage for up to four 220-pound bombs in a bay behind the pilot.

The Yak-9D, introduced in the summer of 1943, was a longer-range escort fighter version carrying additional fuel in two outer wing panel tanks, and an optional tank under the cockpit. It was powered by a 1,360 hp. M-105PF-3 engine.

The Yak-9DD was an even longer-range version (up to 1,367 miles). It was used to escort U.S. heavy bombers on shuttle missions against the Romanian oil fields, and also over Italy and Yugoslavia.

The second generation of Yak-9 fighters began with the Yak-9U prototype, which first flew in December 1943. The "U" stood for Uluchshennyi ("improved" in Russian). The Yak-9U in fact represented a major redesign. It incorporated an improved airframe with a new wing of all metal construction, which had a greater span and area. It was intended to power the improved fighter with the Klimov VK-107A engine of 1,650 hp. Due to production difficulties, the M-105PF-2 engine was substituted until the Fall of 1944, when the VK-107A finally became available in quantity. The Yak-9U became the definitive interceptor/fighter version of the Yak-9 series. The Yak-9UV was a two-seat conversion for training purposes.

The subsequent Yak-9UT had a skin entirely of light alloy. It entered service early in 1945.

The Yak-9PD was an interesting experimental high altitude variant. It had an M-105PD engine with a two-stage supercharger. The armament was reduced to just a single 20mm cannon, firing through the propeller boss, to reduce weight.

The Yak-9P version appeared after the end of hostilities in 1946, and featured an increased armament with one or two fuselage mounted 20mm cannon synchronized to fire through the propeller arc, in addition to the usual cannon mounted in the propeller boss. It saw action in North Korean hands in 1950.

Yak 9 History and development

The Yak-9 represents further development of the successful Yakovlev Yak-7 fighter, taking full advantage of the combat experience with its predecessor. Greater availability of duraluminum allowed for a much lighter construction which in turn permitted a number of modifications to the basic design. The Yak-9 carried two different wings, five different engines, six different fuel tank combinations, and seven types of armament. The first Yak-9 represented a production version of the lightened Yak-7DI and it entered service in October 1942. Yak-9 first saw combat in late 1942 during the Battle of Stalingrad.

Yak-9 remained in production from 1942 to 1948 with 16769 built. In the early 1990's, Yakovlev started limited production of Yak-9's and Yak-3's using original World War II equipment and Allison V-1710 engines for the warbird market.

During 1949 the USSR provided surplus Yak-9P (VK-107) planes to some satellite states in the Soviet block in order to help them rebuild their air forces in the wake of West Berlin's blockade and the allied airlift. Due to human error, a particular section of the plane's cyrillic operating manual was omitted from the translation in some national languages. Before starting the Yak-9, it was necessary to hand-crank a small cockpit-mounted oil pump 25 times to provide initial lubrication to the Klimov engine, something that was not required for World War II German and western fighters equipped with forced-closed cycle lubrication systems. Skipping this unusual step resulted in frequent engine bakings during the take-off roll and initial climb.

When the German Army swept into Russia in June 1941, Luftwaffe chief Herman Goering assured the generals that Germany would destroy Russia’s air defense capability. They very nearly succeeded. Caught by surprise, Russia’s air force was decimated on the ground and in the air. Moving his design and manufacturing facilities east of the Ural Mountains, Alexander Yakovlev‘s design bureau began production of the Yak-9 in 1942, with delivery of the light, versatile craft to fighter regiments by October of that year.

Production of the Yak-9 continued into 1947 and a staggering total of 16769 were built. China received Yak-9P fighters from the USSR after the Communist take-over, and supplied some to North Korea, where they were used against NATO forces at the beginning of the Korean War. Some were shot down by American P-51s. In the five years since the end of WW II, uneasy allies had become active enemies.
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