The series of Yakovlev fighters, which originated with the Yak-1 of 1941, was one of the most important families of combat planes built by the Soviet Union during World War 11. A total of more than 30,000 were built (including 16,769 Yak-9s), and their career lasted well beyond the end of the conflict, continuing until the 1950s. The Yak-9P, the last and best to make use of the airframe, was in fact used during the Korean War.

A Yak-9U of the Guards Regiment, Soviet Air Force 1944

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 calibre 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.

Yak-9

Prototype developed from the Yak-7D1, and initial series production from mid 1942. Armament of one 20 mm ShVAK cannon and one 12.7 mm (0.50 in) UBS machine gun, plus six RS-82 rockets or two 220 lbs (100 kg) FAB-100 bombs.

Yak-9M

Standard version but with the addition of one more 12.7 mm (0.50 in) UBS machine gun.

Yak-9D

Long range escort version with additional fuel capacity extending the range up to 826 miles (1330 km). This model also introduced the the Klimov M-105PF-3 engine. Served from the summer of 1943 onwards.

Yak-9T

Tested in December 1942 with the 11P-37 anti-armour cannon and wing racks for 5.5 lbs (2.5 kg) B hollow charge bombs in special containers. Other Yak-9Ts had the MP-20,VYa-23 or the MP-23VV cannon. Entered service in early 1943.

Yak-9K
 

This version saw limited service in 1943, armed with a 45 mm cannon.

Yak-9B

Special bomber version built in limited numbers. It had an internal bay behind the cockpit which held four 220 lbs (100 kg) FAB-100 bombs or containers with 128 PTAB light bombs.

Yak-9MPVO

A limited number of fighters converted into a night fighter role equipped with a searchlight and the RPK-10 radio compass.
 

Yak-9DD

Ultra long range escort fighter similar to the Yak-9D but with even more fuel capacity bringing the maximum range up to 1,367 miles (2200 km). This aircraft was used to escort US heavy bombers on shuttle raids against the Romanian oil fields. It also equipped the 236th IAD (fighter division) based at Bari in southern Italy and operated for a time over Yugoslavia in support of partisan operations.

Yak-9U

A prototype aircraft that flew in December 1943 with a wing of all metal basic construction. Initially powered by the M-105PF-2 engine, the more powerful VK-107A engine was phased into production aircraft from late 1944 onward.

Yak-9UT

A version of the Yak-9U with light alloy stressed skinning over the entire airframe. Entered service in early 1945.

Yak-9UV

Tandem two seat conversion trainer.

Yak-9P

In addition to the engine mounted 20 mm cannon, this version had one or two fuselage mounted synchronised 20 mm cannon added.

Yak-9R

Was a tactical or photoreconnaissance version with specialized equipment.

Yak-9PD

A high altitude experimental aircraft with the M-105PD engine incorporating a two-stage gear driven supercharger and armed with a single 20 mm cannon. Its believed small numbers of this type, did see action against high flying German reconnaissance aircraft late in the war.

Specifications (Yakovlev Yak-9D)

Type: Single Seat Fighter

Design: Aleksandr Sergeyevich Yakolev

Manufacturer: State Industries

Powerplant: One 1,260 hp (940 kw) Klimov M-105PF 12-cylinder Vee liquid cooled engine.

Performance: Maximum speed 372 mph (600 km/h) at 11,482 ft (3500 m); service ceiling 32,894 ft (10000 m).

Range: 825 miles (1330 km) on internal fuel.

Weight: Empty 6,108 lbs (2770 kg) with a maximum take-off weight of 6,792 lbs (3080 kg).

Dimensions: Span 32 ft 10 in (10.00 m); length 24 ft 11 in (8.50 m); height 9 ft 10 in (3.00 m); wing area 188.3 sq ft (17.50 sq m).

Armament: One 20 mm ShVAK cannon with 100 rounds and two 12.7 mm (0.50 in) UBS machine guns with 250 rounds each plus two 220 lbs (100 kg) bombs.

Variants: Yak-9D, Yak-9M (one additional machine gun), Yak-9B (capable of carrying 883 lbs (400 kg) of bombs), Yak-9T (one 37 mm Nudelmann-Suranov cannon for anti-tank operations), Yak-9K (45 mm cannon), Yak-9DD (increased range), Yak-9MPVO, Yak-9U (one Klimov 1,650 hp (1230 kw) M-107A and a redesigned airframe), Yak-9UT, Yak-9UV, Yak-9R, Yak-9PD, Yak-9P (late and post war production).