Polikarpov I-5

The Polikarpov I-5 (also known as ANT-12) was a single-seat fighter of unequal-span biplane configuration which was the standard Soviet fighter between its introduction in 1933 until 1936. In total 803 I-5's were built, including the prototypes.

Development

The 1928 Five-Year Plan tasked the Tupolev design bureau with developing a mixed-construction (metal and wood/fabric) biplane fighter powered by a Bristol Jupiter VII engine and designated I-5 (ANT-12). Concurrently, Nikolai Nikolaevich Polikarpov's group was tasked with creating a wood-construction aircraft designated I-6 to the same specifications. The I-5 development lagged because the Tupolev bureau was occupied with large bombers and as the result in 1929 the I-5 and I-6 projects were unified under Polikarpov's leadership.

The aircraft was designed by Polikarpov with assistance of Dmitry Pavlovich Grigorovich during the designers time at the Special Design Bureau of OGPU (CKB-39 OGPU) in the Butyrka prison. The maiden flight took place on 29 April 1930, the prototype being known as VT-11' (Vnutrenniya Tyurma - Internal Prison). The second prototype with a Jupiter VI engine 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 named "A gift for the XVI congress of the Party" was powered by a Soviet-built M-15 engine with a NACA cowling.

As Stalin now was pleased with the performance of his new fighter, the design team was released, marking the beginning of Polikarpov's career as the "King of Fighters".

Seven pre-production aircraft were ordered, the new design being given the official designation I-5. As the general design was considered sound, only some minor modifications were being made prior to full production. These included the fitting of a Townend ring cowling, deleting the spinner, fitting an all metal propeller, revising the landing gear struts and modifying the spine.

In late 1932 full scale production started at GAZ-21 factory, with the first production aircraft reaching combat units in February 1933. The full production standard aircraft had a Townend ring around an M-22 engine, a Soviet copy of the Jupiter. The aircraft now also received its armament of two 7.62 mm PV-1 machine guns with 600 rounds per gun.

Design

The aircraft was a single-seat biplane of unequal wing length configuration with fixed landing gear and a tailskid.

The aircraft was of mixed construction, with the aft fuselage being made of a framework of welded steel tubes covered by a riveted duralumin skin. The engine mount and bulkhead were made of welded steel tubes, with the front fuselage section being covered by detachable duralumin panels. For easy access to the tailskid suspension there were also detachable panels there, although these were of aluminium construction.

The upper wing was made in three sections, with the middle section being of duralumin and the outer ones being made of wood. The lower wings were also of wooden construction. All movable control surfaces and the tail section were fabric covered over metal framing.

Operational history

The I-5 started to enter service with the Soviet Air Forces in late 1931, becoming the standard fighter of the Soviet Union, replacing the Polikarpov I-3 and Tupolev I-4. The I-5 started to be replaced by the Polikarpov I-15 from 1935, being completely phased out from front line use by the end of 1937, but continuing in use as an advanced trainer.

A small number was converted for use as fighter-bombers by adding two more PV-1's and by fitting two bomb racks. The ground attack version sometimes goes under the designation I-5LSh. Following the German Invasion of the Soviet Union in June 1941, the heavy losses of front line combat aircraft endured by the Soviet Air Forces together with the disruption of aircraft production resulted in I-5s being removed from training units and returned to front line service as a ground attack aircraft or night bomber, serving both in the defence of Moscow and in Ukraine and the Crimea, serving until early 1942.

Apart from its use as a frontline fighter and fighter-bomber some unarmed I-5s wore civil registration and were used by civil aeroclubs. The I-5 was also involved in the Zveno project as a parasite fighter.

Users

Template:USSR

• Soviet Air Force

Specifications

Data from The Complete Book of Fighters and Shavrov 1985

General characteristics

• Crew: 1
• Length: 6.78 m (22 ft 2⅞ in)
• Wingspan: 10.24 m (33 ft 7 in)
• Height: 3.00 m (9 ft 10 in)
• Wing area: 21.25 m² (228.74 ft²)
• Empty weight: 943 kg (2,079 lb)
• Loaded weight: 1,355 kg (2,987 lb)
• Powerplant: 1× M-22 9 cylinder air-cooled radial engine, 358 kW (480 hp)

Performance

• Maximum speed: 278 km/h (173 mph, 150 knots)
• Range: 660 km (356 NM, 410 mi)
• Service ceiling: 7,500 m (24,605 ft)
• Horizontal turn time: 10 sec

Armament

• Guns:
  
  • 2× 7.62 mm PV-1 machine guns
• Bombs:
  
  • 2× 44 lb (20 kg) bombs

See also

Related development

• Polikarpov I-15
• Polikarpov I-16
• Polikarpov I-153

Comparable aircraft

• Bristol Bulldog
• Gloster Gamecock
• Boeing F3B
• Curtiss Falcon

References

Bibliography

• Abanshin, Michael E. and Gut, Nina. Fighting Polikarpov, Eagles of the East No. 2. Lynnwood, WA: Aviation International, 1994. ISBN 1-884909-01-9.
• Ede, Paul and Moeng, Soph (gen. editors) The Encyclopedia of World Aircraft ISBN 1-85605-705-4
• Gordon, Yefim and Khazanov, Dmitri. Soviet Combat Aircraft of the Second World War, Volume One: Single-Engined Fighters.Earl Shilton, Leicester, UK: Midland Publishing Ltd., 1998. ISBN 1-85780-083-4.
• Gordon, Yefim and Dexter, A. "Polikarpov Biplane Fighter Variants". Wings of Fame, Volume 17. London:Aerospace Publishing, 1999. pp. 106—129. ISBN 1 86184 041 1.
• Green, William and Swanborough, Gordon. The Complete Book of Fighters. New York: Smithmark Publishers, 1994. ISBN 0-8317-3939-8.
• Gunston, Bill. The Osprey Encyclopedia of Russian Aircraft 1975-1995. London:Osprey, 1995. ISBN 1 85532 405 9.
• Léonard, Herbert. Les avions de chasse Polikarpov. Rennes, France: Editions Ouest-France, 1981. ISBN 2-85882-322-7. (French)
• Shavrov V.B. (1985). Istoriia konstruktskii samoletov v SSSR do 1938 g. (3 izd.) (in Russian). Mashinostroenie. ISBN 5-217-03112-3. 
• Stapfer, Hans-Heiri. Polikarpov Fighters in Action, Part 1 (Aircraft in Action number 157). Carrollton, TX: Squadron/Signal Publications, Inc., 1995. ISBN 0-89747-343-4.