The Polikarpov I-15 (Russian: И-15) was a Soviet biplane fighter aircraft of the 1930s. Nicknamed Chaika (Russian: И-15 Чайка, "Lapwing") because of its gulled upper wings, 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) in the Republican Air Force, or "Curtiss" (because its resemblance to Curtiss F9C Sparrowhawk) in the Nationalist Air Force. The I-15 was used in combat extensively by the Republicans in the Spanish Civil War and proved to be one of the best fighter biplanes of its time. The I-15bis also saw a great amount of action in Manchuria and Battle of Khalkhin Gol in the various border clashes between the Russians and the Japanese. In 1937, I-15s in the hands of the Chinese Nationalist Air Force fought against invading Japanese, where the tough biplane began to meet its match in some of the newer, faster Japanese monoplanes. More than 1,000 I-15bis fighters were still in use during the German invasion when the biplane was employed in the ground attack role. By late 1942, all I-15s and I-15bis' were relegated to second line duties. General characteristics

   * Crew: 1
   * Length: 6.10 m (20 ft)
   * Wingspan: 9.75 m (32 ft)
   * Height: 2.20 m (7 ft 3 in)
   * Wing area: 21.9 m² (236 ft²)
   * Empty weight: 1,012 kg (2,231 lb)
   * Loaded weight: 1,415 kg (3,120 lb)
   * Powerplant: 1× M-22 radial engine, 353 kW (473 hp)

Performance

   * Maximum speed: 350 km/h (220 mph)
   * Range: 500 km (310 mi)
   * Service ceiling: 7,250 m (23,800 ft)
   * Rate of climb: 7.6 m/s (1,490 ft/min)
   * Wing loading: 65 kg/m² (13 lb/ft²)
   * Power/mass: 0.25 kW/kg (0.15 hp/lb)

Armament

   * 4 × fixed forward-firing 7.62 mm PV-1 machine guns or
   * 2 × fixed forward-firing 12.7 mm BS machine guns
   * Up to 100 kg (220 lb) of bombs or