Polikarpov I-16
The Polikarpov I-16 was a Soviet single-seat fighter that entered service in the mid-1930s as the world's first low-wing monoplane fighter with retractable landing gear. Designed by Nikolai Polikarpov's bureau, the squat radial-engined fighter fought in Spain, China and Finland, and was still the Soviet Union's most numerous fighter type when Germany invaded in 1941. A handful of examples restored from Russian wrecks fly today.
Why It Mattered
The I-16 was the first low-wing monoplane fighter with retractable landing gear to reach service anywhere in the world, and the formula it pioneered — a cantilever wing, an enclosed cockpit and gear that tucked away — became the standard layout for fighters within a few years. Designed in the Soviet Union by Nikolai Polikarpov's bureau, the squat radial-engined fighter was up to 70 mph faster than the biplane fighters of its day. It fought in Spain, China, at Khalkhin Gol and against Finland before and during the Second World War, and it remained a mainstay of Soviet fighter units right up to Germany's invasion.
Design Notes
The airframe was of mixed construction: a wooden monocoque fuselage formed from glued birch plywood veneer, with metal-framed, largely fabric-covered wings. There was no powered gear retraction — the pilot wound the wheels up and down with a hand crank, 44 turns of it, and carried shears to cut the cables if the mechanism jammed. Early aircraft had a sliding enclosed canopy, but the glazing fogged and pilots disliked it, so later production reverted to an open cockpit behind a small windscreen. Armament grew across the type's many variants, reaching four machine guns and, on some, a pair of 20 mm cannon; the late Type 24 added a more powerful engine, a tail wheel instead of a skid, and underwing rockets or bombs. The type was demanding to fly, with high landing speeds and a reputation for spinning; Soviet pilots said that if you could fly an I-16, you could fly anything.
Operational History
The I-16 first saw combat over Spain in November 1936, when 475 were shipped to the Republican air force; the Nationalists who fought it named it Rata, "rat", while the Republicans who flew it called it Mosca, "fly". Soviet pilots knew it as Ishak, the little donkey. From 1937 it fought over China in Chinese Nationalist service against Japan, and in 1939 it met Japanese fighters again at Khalkhin Gol, on the Mongolian border. It fought Finland over Karelia as well, but by then its limits against modern fighters were plain: against the Messerschmitt Bf 109 it was significantly outclassed. Production ended in 1940, but when Germany invaded in June 1941 the I-16 still made up about 65 percent of the Soviet fighter force, and production was quickly resumed. Reported production totals vary; more than 8,000 were built, and one museum count that includes the two-seat trainers gives 10,292. Spain kept a few Type 10s in service until 1952, the type's last military flying.
Afterlife
Survivors were few and grounded: museum aircraft in Russia, and in Finland a two-seat UTI trainer captured during the Continuation War, the last of its kind. In the 1990s, six I-16s were remanufactured in Novosibirsk from wrecks discovered around Russia for New Zealand's Alpine Fighter Collection. One of them, rediscovered at Lake Yaglyayarvi in Karelia in 1991, now flies with the Flying Heritage and Combat Armor Museum in Everett, Washington. The Military Aviation Museum in Virginia Beach flies another, produced at Gorky in late 1939 and recovered from its Karelian crash site in 1991. In Spain, the Fundación Infante de Orleans keeps an airworthy I-16; after four years on the ground it flew again for the public in February 2024.