The Yakovlev AIR-7, an experimental Soviet light aircraft from the 1930s, showcased remarkable capabilities in terms of high performance.
This single-engined monoplane, designed to accommodate two individuals, underwent rigorous testing and proved its exceptional performance.
However, an incident involving flutter nearly caused the prototype to crash, leading to a temporary setback for its creator, Alexander Sergeyevich Yakovlev, and ultimately preventing any further production of the aircraft.
In April 1931, Alexander Sergeyevich Yakovlev, a recent graduate of the Air Force Academy, was appointed as an engineering supervisor at State Aviation Factory No 39 (GAZ-39), where the renowned designer Nikolai Nikolaevich Polikarpov was serving as an NKVD prisoner.
It is important to note that Yakovlev was not a prisoner but rather a regular employee at the factory, although an “Internal Prison” was present within the premises to house Polikarpov and other designers.
GAZ-39 specialized in the production of Polikarpov’s I-5 fighter, a biplane equipped with a Bristol Jupiter engine manufactured under license.
Yakovlev, however, recognized the potential for a faster aircraft by designing a streamlined monoplane that incorporated the Jupiter engine from the I-5 and could accommodate a passenger.
Despite facing disapproval from GAZ-39’s management, Yakovlev managed to secure funding from Osoaviakhim, the Soviet paramilitary sports society.
He then formed a small team within the factory to undertake the design and construction of the innovative aircraft, which came to be known as the AIR-7.
The resulting aircraft emerged as a meticulously streamlined, two-seat tractor low-wing monoplane, employing a combination of materials in its construction.
The fuselage was meticulously crafted using welded mild steel tubing, featuring dural panelling in the forward section of the cockpit and fabric covering towards the rear.
This design allowed for the pilot and passenger to be seated in tandem beneath a fully enclosed canopy.
The wing, constructed from wood and fabric, was reinforced with cables and overwing steel struts, effectively reducing the need for a thicker wing structure.
To enhance its aerodynamic efficiency, the aircraft was equipped with a fixed conventional landing gear, with the mainwheels enclosed within trouser fairings to minimize drag.
Additionally, a sprung metal tailskid was incorporated into the design.
Powering the aircraft was a single Shvetsov M-22 engine, a licensed version of the Bristol Jupiter radial engine, which was enclosed by a Townend ring and drove a two-bladed propeller.
On 19 November 1932, the AIR-7 embarked on its inaugural flight and achieved a remarkable speed of 335 kilometres per hour (208 mph) on its second flight the following day, with Yakovlev as a passenger.
However, during a demonstration in front of senior officers of the Soviet Air Forces on 23 November, the starboard aileron of the AIR-7 broke off mid-flight, leading to a forced landing.
The AIR-7 was repaired after the accident, with reinforced aileron hinges and modified undercarriage fairings, and went on to set a new national speed record of 332 kilometres per hour (206 mph) on 25 September 1933.
Yakovlev took responsibility for the accident, citing an error in the calculation of the aileron hinge’s strength.
Despite his explanation, the commission investigating the incident refused to consider his evidence and recommended that he be barred from design work and not receive any awards.
Consequently, Yakovlev and his team were dismissed from OKB-39.
Nevertheless, Yakovlev used his connections in the Communist Party to establish the Yakovlev OKB in a dilapidated Moscow bed factory in 1934, where he resumed his aircraft design work.
Specifications Crew One Capacity One passenger Length 7.80 m (25 ft 7 in) Wingspan 11.00 m (36 ft 1 in) Height 3.10 m (10 ft 2 in) Wing area 19.40 m2 (208.8 sq ft) Airfoil Göttingen-436 Empty weight 900 kg (1,984 lb) Gross weight 1,400 kg (3,086 lb) Powerplant 1 × Shvetsov M-22 9-cylinder air-cooled radial engine, 360 kW (480 hp) Performance Maximum speed 332 km/h (206 mph, 179 kn) Range 270 km (170 mi, 150 nmi) (normal range) Ferry range 1,300 km (810 mi, 700 nmi) (maximum range) Service ceiling 5,800 m (19,000 ft) Time to altitude 3 min to 1,000 m (3,300 ft) Sources Yakovlev Aircraft Since 1924 – Bill Gunston & Yefim Gordon. OKB Yakovlev, A History of the Design Bureau and its Aircraft-Yefim Gordon, Dmitriy Komissarov & Sergey Komissarov. Soviet Aircrafts Illustrated-A.S.Yakovlev. The History of Soviet Aircraft from 1918-Vaclav Nemecek. Soviet AF Fighter Colours 1941-45-Erik Pilaeskii. Soviet Combat Aircraft of the Second World War, Vol 1, Single Engined Fighters-Yefim Gordon and Dmitri Khazanov. Early Soviet Jet Fighters, The 1940s and early 50s-Yefim Gordon. Soviet Secret Projects, Fighters Since 1945-Tony Buttler & Yefim Gordon. Soviet Secret Projects, Bombers Since 1945-Tony Buttler & Yefim Gordon. Soviet Aircraft of Today-Nico Sgariato. Modern Soviet Fighters-Mike Spick.