The Yakovlev AIR-7 was a prototype

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

high performance light aircraft of the 1930s. It was a two-seat single-engined

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

, which demonstrated excellent performance during testing. After the prototype almost crashed as a result of flutter, its designer,

Alexander Sergeyevich Yakovlev Alexander Sergeyevich Yakovlev (; 22 August 1989) was a Soviet aeronautical engineer. He designed the Yakovlev military aircraft and founded the Yakovlev Design Bureau. Yakovlev joined the Communist Party of the Soviet Union in 1938. Biography ...

suffered temporary disgrace and no production followed.

Design and development

In April 1931,

, freshly graduated from the air force academy, was assigned as an engineering supervisor to State Aviation Factory No 39 (

GAZ Gaz may refer to: Geography *Gaz, Kyrgyzstan Iran * Gaz, Darmian, village in South Khorasan province * Gaz, Golestan, a village in Bandar-e Gaz County * Gaz, Hormozgan, a village in Minab County * Gaz, Kerman, a village * Gaz, North Khorasan, a ...

-39) where the designer

Nikolai Nikolaevich Polikarpov Nikolai Nikolaevich Polikarpov (; – 30 July 1944) was a Soviet aeronautical engineer and aircraft designer, known as the "King of Fighters". He designed the I-15 series of fighters, and the I-16 Ishak ( phonetically close to its or designa ...

worked as an

NKVD The People's Commissariat for Internal Affairs (, ), abbreviated as NKVD (; ), was the interior ministry and secret police of the Soviet Union from 1934 to 1946. The agency was formed to succeed the Joint State Political Directorate (OGPU) se ...

prisoner. (While the factory included an "Internal Prison" which housed Polikarpov and many other designers, Yakovlev was a normal employee at the factory and not a prisoner).Gunston and Gordon 1997, p. 9. GAZ-39 specialised in production of Polikarpov's I-5 fighter, a

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

Bristol Jupiter The Bristol Jupiter is a British nine-cylinder single-row piston radial engine that was built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developme ...

engine and Yakovlev realised that a

light aircraft designed around the Jupiter engine of the I-5 and carefully streamlined could reach a higher speed than the I-5 while carrying a passenger.Gordon, Komissarov and Komissarov 2005, pp. 26–27.Gunston and Gordon p. 30. Despite disapproval from the management of GAZ-39,Gunston 1995, p. 455. Yakovlev received funding from

Osoaviakhim DOSAAF (), full name ''Volunteer Society for the Assistance to the Army, Aviation, and Navy'' (), was a paramilitary sport organization in the Soviet Union that was concerned mainly with weapons, automobiles and aviation. The society was establ ...

, the Soviet paramilitary sports society, and assembled a small team within the factory to design and build the new aircraft, the AIR-7. The resulting aircraft was a carefully streamlined two-seat

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...

low-wing

of mixed construction. Its fuselage was built of welded mild steel tubing, with

dural Dural is a semi rural suburb of Sydney, in the state of New South Wales, Australia 36 kilometres north-west of the Sydney central business district in the local government areas of Hornsby Shire and The Hills Shire. Dural is part of the Hills ...

panelling forward of the cockpit and fabric covering aft, and accommodated the pilot and passenger in tandem under an enclosed canopy. The wood and fabric wing was braced with cables and overwing steel

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for ...

s to the fuselage, enabling a thinner wing to be used. The aircraft was fitted with a fixed

conventional landing gear Conventional landing gear, or tailwheel-type landing gear, is an aircraft Landing gear, undercarriage consisting of two main wheels forward of the Center of gravity of an aircraft, center of gravity and a small wheel or skid to support the tail ...

, with the mainwheels enclosed in trouser fairings to reduce drag, with a sprung metal tailskid. Powerplant was a single Shvetsov M-22, a license-built

radial engine The radial engine is a reciprocating engine, reciprocating type internal combustion engine, internal combustion engine configuration in which the cylinder (engine), cylinders "radiate" outward from a central crankcase like the spokes of a wheel. ...

enclosed by a

Townend ring A Townend ring is a narrow-chord (aircraft), chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling. It was patented in 1929, and found use on various aircraft of the 1930s and into the 1940s ...

, driving a two-bladed propeller.Gunston 1995, pp. 454–455.Gunston and Gordon 1997, pp. 30–32.

Operational history

The AIR-7 made its maiden flight on 19 November 1932. It reached a speed of , a Soviet airspeed record, on its second flight the next day, despite carrying Yakovlev as a passenger. On 23 November, the AIR-7 was being demonstrated in front of senior officers of the

Soviet Air Forces The Soviet Air Forces (, VVS SSSR; literally "Military Air Forces of the Union of Soviet Socialist Republics"; initialism VVS, sometimes referred to as the "Red Air Force") were one of the air forces of the Soviet Union. The other was the Sovie ...

when its starboard

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...

broke off in flight, apparently the result of flutter, and the test pilot made a forced landing.Gordon, Komissarov and Komissarov 2005, p. 28. Yakovlev took responsibility for the accident, stating that an error had been made in calculating the strength of the aileron hinge. The commission investigating the accident, which refused to listen to any evidence from Yakovlev, concluded that Yakovlev should be prohibited from carrying out design work and should not receive an award for which he had been recommended. He and his team were sacked from OKB-39. Yakovlev eventually used his connections in the Communist Party to gain permission to restart aircraft design work, setting up what became the Yakovlev OKB in a derelict Moscow bed factory in 1934.Gunston and Gordon 2005, p. 10. The AIR-7 was repaired after the accident, fitted with strengthened aileron hinges and modified undercarriage fairings. So modified, it set a new national speed record of on 25 September 1933.

Specifications

Notes

Citations

References

* Gordon, Yefim, Dmitry Komissarov and Sergey Komissarov. ''OKB Yakovlev: A History of the Design Bureau and its Aircraft''. Hinkley, UK: Midland Publishing, 2005. . * Gunston, Bill. ''The Osprey Encyclopedia of Russian Aircraft 1975–1995''. London, UK: Osprey, 1995. . * Gunston, Bill and Yefim Gordon. ''Yakovlev Aircraft since 1924''. London, UK: Putnam Aeronautical Books, 1997. .

External links

Yakovlev Design Bureau: Early Aircraft: AIR-7
{{Yakovlev aircraft 1930s Soviet sport aircraft AIR-7 Single-engined tractor aircraft Low-wing aircraft Aircraft first flown in 1932 Aircraft with fixed conventional landing gear Single-engined piston aircraft