I-15 and I-15bis
Role Fighter
Manufacturer Polikarpov
Designer Nikolai Nikolaevich Polikarpov
First flight October 1933
Introduction 1934
Status retired
Primary users Soviet Air Force
Spanish Republican Air Force
Chinese Nationalist Air Force
Mongolian People's Army Air Force
Produced 1934–1937[1]
Number built 3,313 (plus 3,437 I-153)[1]
Developed from Polikarpov I-5
Variants Polikarpov I-153

The Polikarpov I-15 (Russian: И-15) was a Soviet biplane fighter aircraft of the 1930s. Nicknamed Chaika (Russian: Чайка, "Seagull") because of its gulled upper wings,[2][3] it was operated in large numbers by the Soviet Air Force, and together with the Polikarpov I-16 monoplane, was one of the standard fighters of the Spanish Republicans during the Spanish Civil War, where it was called Chato (snub-nose).[4]

Design and development

Polikarpov I-15 showing gulled top wing

The design for the 14th fighter for the VVS, the I-14, started as an advanced (for the era) monoplane under the direction of Andrei Tupolev. He grew concerned that the design would not mature, and ordered two backup biplane designs as the I-14A and B just to be safe. Polikarpov had just been released from prison in August 1932, and was handed the I-14A project. When both the I-14 and I-14A were ordered into production, Polikarpov's design, a development of the I-5 fighter became the famous I-15.[citation needed]

The first flight was made in October 1933 with V.P. Chkalov at the controls, powered by an imported Wright R-1820 Cyclone engine.[5] The I-15, also known by its development name TsKB-3, was a small biplane fighter with a gulled upper wing. The single bay wings were of wooden construction, while the fuselage was of mixed steel and duralumin construction, with a fabric covered rear fuselage.[3]

Production started in 1934, initially being powered by the Shvetsov M-22, a licence-built version of the Bristol Jupiter radial engine.[6] While less powerful than the Cyclone, the M-22 powered aircraft were still superior to the I-5 which it replaced, demonstrating excellent manoeuvrability.[3] Production switched to the 515 kW (691 hp) Shvetsov M-25 engine (a license-built, metricified Cyclone) in late 1936.[2] A total of 671 I-15s were built, 284 in the Soviet Union and a further 287 under license by CASA in Spain.[7]

The gulled upper wing of the I-15 was unpopular with some pilots, as it was felt to restrict visibility, so Polikarpov's design bureau produced a revised version, again powered by the M-25, with a longer span un-gulled upper wing.[6][2] This version, the I-15bis, commenced production in 1937,[8] a total of 2,408 I-15bis' being delivered by the time production finished in 1940.[2]

Operational history

Chinese Polikarpov I-15bis with pilot Xu Jixiang of the 17th PS, 5th PG who fought the new IJNAF A6M Zero-sen air-superiority fighter on 13 September 1940 in the I-15bis during the Battle of Chonqing[9][10]


In August 1937, the Chinese Kuomintang Government signed a non-aggression pact with the USSR, and in autumn of the same year, the Soviet Union commenced to ship I-15s as a part of a programme of military aid to the Chinese Air Force (CAF) in its defensive war against Japan. More than 250 Soviet pilots volunteered to fly the 255 I-15s supplied to China in autumn 1937. By 1939, the total number of Polikarpov biplanes delivered to CAF reached 347 I-15/I-15bis.[11] The I-15bis also saw a great amount of action in the Soviet–Japanese border conflicts along the China–Mongolia border. From 1938-1941, I-15s in the Nationalist Air Force of China, fought many major battles, and skirmishes against invading and occupying Japanese forces, including the Battle of Taierzhuang, the Battle of Wuhan, the Battle of South Guangxi, the Battle of Chongqing-Chengdu, etc. The tough biplane was quite clearly outmatched during the debut dogfight against the new Mitsubishi A6M Zero fighter over Chongqing on 13 September 1940, although I-15bis pilots Maj. Zheng Shaoyu, Lt. Gao Youxin, and Lt. Xu Jixiang were able to target and damage some of the Zeroes, with Lt. Gao believing he had shot one down (all Zeroes returned to base in Wuhan, with four Zeroes suffering some damage); all three of those pilots survived the battle.[12][13][14]


In 1939 Polikarpov fighters were extensively used during the Battles of Khalkhin Gol fought around the Khalkha River in Dornod Province. The battles were fought during 11 May–16 September 1939, and involved more than 600 planes. When hostilities commenced, the only I-15bis in the area were 14 aircraft of 70th IAP. Their number increased in the following weeks: on 23 May, 35 I-15bis from 22nd IAP arrived from the Trans-Baikal region.[6] However the Mongolian Polikarpov pilots had been hastily trained and they suffered heavy losses against the more experienced Japanese pilots. During this conflict, the Soviet Union, Mongolia and Japan lost more than 200 aircraft each.[15] 10 aircraft were delivered to the Mongolian People's Army Air Force in mid-July 1939 and flight personnel were trained for rear air defence. Afterwards, they received more than 30 aircraft in March 1942.[citation needed]


The I-15 was used extensively in combat by the Republicans in the Spanish Civil War and proved to be one of the best fighter biplanes of its time. The Nationalists called the fighter "Curtiss", apparently believing it to be the Curtiss F11C Goshawk. The first batch of 25 Polikarpovs arrived in Cartagena, Spain, on 28 October 1936,[6] with 15 pilots, led by future ace Pavel Rychagov. A few days later a further group of 10 pilots and 15 aircraft arrived in Bilbao.[16][6]

The Soviet pilots first went into action 4 November, when I-15s shot down two Junkers Ju 52/3ms and two CR.32s over Madrid, and forced a third Ju 52 and a Heinkel two-seater to crash-land.[6] No losses were reported among the Soviet pilots. During the next two days, Chato pilots claimed 12 more victories, at the cost of two I-15s lost.[17]

On 16 November, while dogfighting with Fiat CR.32s over Madrid, future ace Rychagov was shot down [18] and four days later the number of combat-ready Polikarpov in the central area had fallen to 15 aircraft: seven had been lost in combat, two had force-landed and one was undergoing repair.[17]

In December 1936 and January 1937, two more shipments of 30 aircraft arrived in Spain, making it possible to form four full-strength I-15 squadrons. Until the spring of 1937, central Spain was the main war theatre for I-15s. And in May 1937, another batch of 31 Polikarpov landed in Spain, taking the total number of I-15s delivered to 116.[19]

Chato losses in the Spanish Civil War were comparable to those of its principal rival, the Fiat CR.32. By 1 January 1939, 197 Polikarpovs had been lost: 88 shot down by enemy aircraft and nine by anti-aircraft artillery, 27 destroyed on the ground and 67 written off in accidents.[20]

World War II

More than 1,000 I-15bis fighters were still in Soviet use during the German invasion when the biplane was employed in the ground attack role. Many were destroyed in the opening hours of the invasion sitting in neat rows on their runways.[6] By November 1943, all examples still in service had been relegated to second line duties.[6]


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Polikarpov I-15bis in flight
Prototype fitted with the more powerful M-25V radial piston engine.
First production series.
Single-seat fighter biplane, armed with four 7.62 mm (0.30 in) PV-1 or ShKAS machine guns, plus up to 150 kg (330 lb) of bombs. The I-15bis was powered by the more powerful 570 kW (760 hp; 770 PS) Shvetsov M-25V radial piston engine. It had a straight upper wing. A total of 2,408 machines were built.
Modernised version of I-15bis. One built in 1938. Series production was not undertaken, since it was decided to build I-153 instead.
(Germetichyeskoi Kabine – hermetic (pressure) cabin) – One aircraft fitted with a pressure cabin.
(Turbo Kompressor – turbo-charged) – One aircraft fitted with two turbochargers.
I-15ter (I-153)
Development of the I-15 with retractable landing gear, see Polikarpov I-153.
(Oochebno Trenirovochnyy Istrebitel' – fighter trainer) – Factory-built two-seat trainer version, front cockpit moved forwards, dual controls fitted, 20 built in 1934 but not used by VVS[6]
Chung 28B
China product version. base on I-152,equip with 712hp Wright R-1820-F3 engine,armed with four .30 Browning machine gun,total 30 built.


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Spanish Republican Air Force "Chato"
 Republic of China
 Nazi Germany
Mongolia Mongolia
 Soviet Union
Spain Spanish Republic

Specifications (I-15 M-25)

Polikarpov I-15 drawing

Data from Of Chaika and Chato…[21]

General characteristics



See also

Related development

Aircraft of comparable role, configuration, and era

Related lists



  1. ^ a b "Polikarpov fighters." wio.ru. Retrieved: 8 October 2012.
  2. ^ a b c d Gunston 1995, p. 299.
  3. ^ a b c Green and Swanborough 1979, p. 10.
  4. ^ Lannon 2002, p. 46.
  5. ^ Green and Swanborough 1979, p. 9.
  6. ^ a b c d e f g h i Smith, Peter (2014). Combat Biplanes of World War II. United Kingdom: Pen & Sword. p. 635. ISBN 978-1783400546.
  7. ^ Gordon and Dexter 1999, p. 120.
  8. ^ Green and Swanborough 1979, p. 18.
  9. ^ Cheung, 2015, pp. 76, 80-81. Hsu Chi-hsiang (徐吉驤-Xu Jixiang) was shot down in his I-15bis in the air-combat debut of the A6M Zero on 13 September 1940... a 20mm shell went through his amenities kit blowing all the bristles off his toothbrush... Hsu would exact some personal revenge on 04 March 1944 over the Japanese airbase at Chiung-Shan (Qiongshan) on Hainan island... shooting down the lead Zero in a flight of three... the flight leader or perhaps the instructor
  10. ^ 蔡, 乔治. "九一三壁山空戰". www.flyingtiger-cacw.com. Retrieved 2021-01-23. 他的性能遠在伊-152(bid)、伊-16-10之上,可以認為,敵我雙方的戰機性能差了一個數量級還多,如此之下,如何還能奢談"取勝"?在戰鬥中,徐吉驤的座機被莫名日機連續咬尾多次,遭受了十幾次攻擊,已經被打得體無完膚,敵機射彈密集,徐吉驤座機上連細細的翼間張線都被打得卷起來了。徐吉驤感到自己四周的防彈鋼板被子彈敲得叮叮作響,所幸他還沒有中彈。最後,他座機發動機的潤滑油漏光了,這架伊-152在璧山上空停車。徐吉驤迅速判斷了一下形勢,決定不跳傘,以免被兇殘的日機沖傘射擊。他躲掉日機攻擊後奇跡般的迫降在一片稻田裡,飛機被摔得七零八落。幸好燃油、滑油均已耗盡,飛機沒有燃燒。徐吉驤機智地躲在座機殘骸內,等盤旋在頭頂的兩架日機離去後,才爬出完全損壞的座機。
  11. ^ Maslov 2010, p. 33.
  12. ^ Cheung, 2015, pp. 74-75. Lt. Gao had shot A6M Zeroes of the tails of other Chinese fighters in the melee over Chongqing on 13 September 1940, closing in to 160 ft of one... claiming one shot down...
  13. ^ Chen, C. Peter. "Gao Youxin". WW2DB. Retrieved 2020-11-27. <In Sep 1940 (9/13/1940), Lt. Gao Youxin flew against the new A6M Zero fighters, damaging one... he had claimed a victory but no A6M fighters were lost in that action.
  14. ^ 萨沙, 资深中国近代军事历史作家 (2019-05-09). "永不归航的红色年轻战鹰:1位"八路军"青年战士的抗日空战". 知乎专栏 (in Chinese). Retrieved 2020-12-21. <郑少愚在此战中第五次受伤,他的右手和左足均中弹负伤,座机更被击成重伤。他虽然受伤,但依旧表现英勇。根据《空军第一路司令官毛邦初关于敌我空军交战情况的战斗要报》(1940年9月13日)中记载:"总领队郑大队长虽手足均受弹伤,但仍奋勇迎敌,援救友机多架,战斗终结,掩护各机飞返遂宁。
  15. ^ Maslov 2010, p. 42.
  16. ^ Maslov 2010, p. 16.
  17. ^ a b Maslov 2010, p. 18.
  18. ^ Maslov 2010, p. 17.
  19. ^ Maslov 2010, p. 21.
  20. ^ Maslov 2010, p. 24.
  21. ^ Green and Swanborough 1979, p. 12.
  22. ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.


Further reading

The initial version of this article was based on material from aviation.ru. It has been released under the GFDL by the copyright holder.