Soviet Monoplane I-5 1/72 ICM 72053

TThe Polikarpov I-5 was a single-seat biplane which became the primary Sovietfighter between its introduction in 1931 through 1936, after which it became the standard advanced trainer. Following Operation Barbarossa, which destroyed much of the Soviet Air Forces (VVS), surviving I-5s were equipped with four machine guns and bomb racks and pressed into service as light ground-attack aircraft and night bombers in 1941. They were retired in early 1942 as Soviet aircraft production began to recover and modern ground-attack aircraft like theIlyushin Il-2 became available.

The 1928 Five-Year Plan ordered the Tupolev design bureau to develop a mixed-construction (metal and wood/fabric) biplane fighter powered by a Bristol Jupiter VII engine with the first prototype completed by 1 September 1929. The new fighter was designated I-5 (Istrebitel'—Fighter), but had the internal Tupolev designation of ANT-12. Concurrently, Nikolai Nikolaevich Polikarpov's group was tasked with creating a wood-construction aircraft designated as the Polikarpov I-6 to the same specification. The I-5 design, begun by Pavel Sukhoi, under the supervision of Andrei Tupolev, lagged because the Tupolev bureau was preoccupied with large bombers. As the result the I-5 and I-6 projects were unified in 1929 under Polikarpov's leadership, although neither project met its specified completion date.

Nikolai Polikarpov was arrested by the OGPU in September 1929 for the crime of industrial sabotage for these failures and sentenced to death, although this was commuted to ten years imprisonment in a labor camp. In December 1929 the OGPU gathered a number of aircraft engineers together at Butyrka prison, including Polikarpov, and formed the Internal Prison Design Bureau (Konstruktorskoye Byuro Vnutrenniya Tyurma—KB VT) under the leadership of Dmitry Pavlovich Grigorovich. The KB VT was transferred to quarters on the grounds of Factory (Zavod) Nr. 30 in Moscow-Khodinka in early 1930. Shortly afterwards Polkarpov replaced Grigorovich as the head designer when his concept for the I-5 was approved by the OGPU. The full-scale mock-up was approved on 28 March 1930 and the first prototype, designated VT-11 (Vnutrenniya Tyurma—Internal Prison), was completed a month later.

It made its first flight on 30 April 1930 and was fitted with an imported supercharged 450-horsepower (340 kW) Jupiter VII. It was painted in silver with a red cheat line; a red "VT" was superimposed on the red star on the rudder. The second prototype, known as the VT-12, had a Jupiter VI engine, and took to the air on 22 May, bearing the name "Klim Voroshilov." The two prototypes also differed in minor details regarding the shape of the tail and the construction of the landing gear. All this meant a slight difference in weight and performance between the two prototypes was present, with the second being slightly heavier and faster, while the first had a slight range advantage and a higher service ceiling. The third prototype, designated as the VT-13 and inscribed with "A Gift for the XVIth Congress of the Party", was powered by a 600-horsepower (450 kW) Soviet-built M-15 engine with a NACA cowling, but this proved to be unreliable and was not put into production.

The I-5 was a single-seat biplane with staggered wings in a sesquiplane configuration with fixed landing gear and a tailskid. The aircraft was of mixed construction, with the fuselage being made of a framework of welded steel tubes covered by a fabric skin over the rear fuselage, with the front fuselage section being covered by detachable duralumin panels as far back as the rear of the cockpit. There were also detachable panels allowing easy access to the tailskid shock absorber. The fabric skin was laced for tightness and the seams were covered with calico. A fireproof bulkhead separated the 165 litres (36 imp gal; 44 US gal) fuel tank from the engine and a fire extinguisher was fitted with outlets to the fuel pump, inlet pipe and carburetor. The conventional landing gear was connected by a one-piece axle and some aircraft were fitted with teardrop-shaped spats covering the wheels. Initially the tailskid was fixed, but later aircraft had smaller skids that moved in concert with the rudder. Rubber rings were used as shock absorbers on the landing gear.

The wings were built with two spars. The upper wing was made in three parts, with the middle section being of duralumin and the outer ones being made of wood. The wooden lower wings were built in single sections, using a Göttingen-436 profile. The duralumin N-type struts that separated the wings, and attached the upper wing to the fuselage, had a teardrop profile and were reinforced with steel bracing wires. Laced lacquered fabric covered the empennage and wings, except for the roots of the lower wings which were covered inplywood and the leading edges of the wings were skinned in duralumin for the first 150 cm (59 in). Ailerons were fitted only to the upper wing. All movable control surfaces and the tail section were built with doped fabric over metal framing. Bracing wires above and below the tail were fitted on the prototypes, but production aircraft replaced the lower wires with a strut on each side. The horizontal tail was offset 3.5 mm (0.14 in) to port to compensate for the engine's torque, but it could be adjusted on the ground.

I-5
An I-5 in flight
Role	Fighter
National origin	Soviet Union
Manufacturer	Polikarpov
Designer	N. N. Polikarpov
First flight	29 April 1930
Introduction	1931
Retired	1942
Primary user	VVS Naval Aviation
Produced	1931–34
Number built	803