Evolved from the earlier Polikarpov I-5, the I-15 introduced a gull-shaped upper wing (“Chaika” or “Seagull”) to improve upward visibility and reduce drag.
Powerplant
Initially powered by the M-22 radial engine (licensed Bristol Jupiter), it was later upgraded to the M-25 (licensed Wright Cyclone) in the I-15bis.
Armament
Typically, four 7.62 mm PV-1 or ShKAS machine guns, with bomb-carrying capability added in later variants.
Production and Variants
Production Years
1934–1937
Total Built
Approximately 3,313 I-15 series aircraft, including 647 I-15 and 2,408 I-15bis.
Key Variants
I-15bis
Straight upper wing, improved engine, most widely produced.
I-152
The modernised prototype led to the I-153.
I-153 “I-15ter”
Featured retractable landing gear and aerodynamic refinements.
UTI-1
Two-seat trainer version.
Chung 28B
Chinese-built variant with a Wright R-1820-F3 engine.
A.4
Spanish designation for I-15 fighters used during the Civil War.
Operational History
Spanish Civil War (1936–1939)
Supplied to the Spanish Republicans, where it was nicknamed “Chato” (snub-nose).
Proved agile and effective against German and Italian aircraft early in the conflict.
Flown by Soviet volunteers and Spanish pilots.
Second Sino-Japanese War (1937–1945)
Used by Chinese Nationalist forces, including Soviet-supplied and locally built variants.
Participated in air defence and ground attack missions against Japanese forces.
Soviet Union
Winter War (1939–1940)
Used for ground attack and air support against Finland.
World War II (1941–1945)
Still in service during Operation Barbarossa, though largely obsolete.
Used in secondary roles such as training, reconnaissance, and night harassment.
Mongolia
Participated in the Battle of Khalkhin Gol (1939) against Japanese aircraft.
Legacy
The I-15 was a transitional aircraft bridging early biplane designs and more modern monoplanes.
Though outclassed by newer fighters by the late 1930s, its agility, ease of maintenance, and mass production made it a valuable asset in multiple conflicts.
It laid the groundwork for the I-153 and contributed to Soviet tactical doctrine in the interwar period.
