The Polikarpov I-16 was a Soviet single-engined, single seat fighter designed in the early 1930s and used during World War II.
Despite being largely obsolete by the start of the war, it was still one of the most commonly used aircraft in the Soviet arsenal during the early stages of Germany's invasion.
The I-16 required a crew of one, and was powered by a Shvestov M-25A engine that gave it a top speed of 439 km/h. The service ceiling of the I-16 was around 9,000 meters while its operational range was 800 kilometers. It was armed with two 7.62 mm machine guns and could carry up to six rockets or 200 kg of bombs.
Most notable feature of the design was a short body and low monoplane wings, possibly inspired by the Gee Bee racing aircraft of the 1930s. Handling was adequate however compared to later designs, it was hardly maneuverable enough to deal with more advanced German and Italian fighters. The total weight of the I-16 was around 1,300 kilograms while its total length was around 5.7 meters. Wingspan was around 9.14 meters.
The Polikarpov had numerous variants produced during its career with the Type 6 being the first major model being made. It featured a new engine and improved exterior armor. Following was the Type 10 model which had a new armament of four MGs and an updated engine. The Type 17 was a model further updated for heavy combat. It had dual 20mm autocannons mounted. Secondly, it had a reinforced superstructure that was able to withstand more damage in combat. The next variants, the Type 18 and 24 were both fitted with new and improved engines and superchargers as well as the Type 28 and Type 30.
Initially designed as the TsKB-12 during 1932/33, the 480 hp (358 kW) M-22 powered prototype of the I-16 was first flown on 31 December 1933, eventually reaching a max speed of 223 mph (359 km/h) at sea level. This was followed by the TsKB-12bis, powered by an imported 710 hp (529 km/h) Wright SR-1820-f3 Cyclone, which boosted speed to 272 mph (437 km/h) at 9,845 ft (3,000 m). The type's speed and excellent rate of climb resulted it gaining official support, resulting in the building of an evaluation batch of 30 I-16s with M-22 engines, with 10 examples participating in the flypast over Moscow on May Day 1935. Armed with a pair of wing mounted 0.3 in (7.62 mm) ShKAS machine guns, these were Officially designated I-16 Type 1, although the designation I-16M-22 was also used.
These were followed by the M-25 powered I-16 Type 4, which first flew on 18 February 1934, but was not selected for production for 18 months, as the take off run of 985 ft and landing run of 735 ft meant the existing fighter airfields were too small for the type. This led to the widespread enlargement of all fighter airfields, and production of the Type 4, from July 1935. Problems with limited stability in flight, and operation of the undercarriage,[N 1] led to increasing numbers of casualties, prompting development of a two-seat training variant designated I-16UTI. Comprising 25% of production, the UTI had a second cockpit fitted in front of the standard cockpit, with the main fuel tank being redesigned and reduced in size. In addition, factory built UTIs had the undercarriage locked in the lowered position, and the retraction mechanism was not fitted.[N 2]
Retaining the twin ShKAS armament of the Type 1, the Type 4 was followed by the I-16 Type 5 with seat armour as standard and minor equipment revisions, and the I-16 Type 6 which, powered by the 730 hp M-25A engine, became the first I-16 variant to see active service, when a number were dispatched to Spain for use by the Republican forces, who in March 1937 assigned them and their Russian pilots to Fighter Group 31, which comprised seven squadrons of 15 aircraft each.
- The mechanism frequently became stuck before the wheels were fully retracted, forcing pilots to carry a pair of cable cutters, so they could release the undercarriage in an emergency by severing the cables in the cockpit.
- A number of early production single seaters were also fitted with a second cockpit, retaining the retractable undercarriage.
- Gunston, Bill. Illustrated Directory of Fighting Aircraft of World War II. Salamander Books. 1988. ISBN 0-86101-390-5 Page 85
- World Aircraft Information Files Aviation Partwork. Midsummer Books Ltd. File 904 Sheet 8 (A-Z of Aircraft:Pitts S-1 and S-2 to Polikarpov I-16)
- World Aircraft Information Files. File 904 Sheet 9 (A-Z of Aircraft:Polikarpov I-16 (continued) to Polikarpov U-2 and Po-2)
- Green, William. Famous Fighters of the Second World War. Purnell Book Services. 1975. Page 156
- Green, William - Fighters. Page 157