Probably world's most advanced fighter in 1933, this diminutive monoplane still was a formidable opponent in 1941.
The Polikarpov I-16 is one of the most unsung aircraft in history, almost the Rodney Dangerfield of fighters, getting no respect from anyone - except its opponents. Created by designer Nikolai Nikolayevich Polikarpov, this classic airplane was a brilliant leap forward, particularly for a Soviet aviation industry that was still in its infancy. It was not only the first cantilever monoplane fighter with retractable landing gear to see squadron service in any country in the world, it also was one of the longest-lived fighters of the period, serving until as late as 1950, in Spain.
Among Polikarpov's many designs was the U-2 (later the Po-2), a remarkably simple but efficient two-place biplane that was built in greater quantity than any other aircraft in history, with some sources citing as many as 41,000 examples being delivered. He was also responsible for the I-15 and I-153 biplanes that formed the core of Soviet fighter strength for many years. These were remarkably adaptable designs, fully equivalent to the Boeing F4B-4 or Gloster Gauntlets of the time. Some were even used for wild experiments, including pressure cabin studies and ramjets - rather unusual for fabric-covered biplanes!
But it was the I-16 that would prove to be Polikarpov's major contribution to aviation history. Design work began in early 1933, with the first flight taking place on December 31 of that year. Although somewhat difficult to fly, the I-16's speed, high roll-rate, and rate of climb earned it production status. The aircraft was produced from 1934 through 1941, with 7,005 single-seaters and 1,639 two-seater UTI-1, -2 & -4 trainers built (some sources insist that a total number of airframes was higher, 10,292).
Like most Soviet aircraft of the period, the Polikarpov I-16 was of mixed construction, with a fabric-covered metal wing and a plywood-covered fuselage of steel-tube construction. Its unusual shape was inspired by the record-setting Gee-Bee R1 (and not by the P-26 Peashooter, as some good people tend to think).
The TsKB-12 was designed around the Wright Cyclone SR-1820-F-3 nine cylinder radial engine (rated at 529 kW/710 hp); a license to build this engine was being negotiated. As the license was not yet approved, Polikarpov was asked to settle for the less powerful M-22 (Soviet-built version of the Gnome-Rhone Jupiter 9ASB which itself was a licensed version of the Bristol Jupiter VI) with 358 kW (480 hp). This was deemed acceptable because the projected top speed still exceeded 300 km/h (185 mph).
The M-22 powered TsKB-12 first took to the air on 30 December 1933 with the famous Soviet test pilot Valery Chkalov at the controls. The second TsKB-12 with a Cyclone engine and three-bladed propeller flew in January of the following year. Initial government trials in February 1934 revealed very good maneuverability but the aircraft did not tolerate abrupt control inputs.
The Type 4, still M-22 powered, was the first to enter serial production. But soon it was supplanted and subsequently replaced with the Type 5 boasting the M-25 engine - a license-produced Wright Cyclone. Later, a massive 1,100-horsepower M-63 engine was installed, giving the I-16 a top speed of more than 326 mph - and even trickier handling.
The I-16 was initially armed with two or four ShKAS machine guns. Its ground attack was fitted two ShVAK cannons in the wings. Types 17 and 24 carried mixed armament of two ShKAS / two ShVAK or a heavy UBS MG. Many variants could carry RS-82 rockets, bombs, extra fuel tanks. A turbocharged high-altitude version was also developed but didn't enter production. It was even used as a parasite bomber in the Zveno project (see Tough Tupolev):
The Soviet Union is said to have sent more than 500 (or at least 475) Polikarpov I-16s to Spain during the Spanish Civil War of 1936-39. In combat, the I-16, nicknamed Mosca (fly) by the Republicans and Rata (rat) by the Nationalists, was clearly superior to the German Heinkel He 51 and Italian Fiat CR-32 biplanes.
The I-16 in post-Civil War Spanish colors. Served until 1950s
In China and Manchuria, their opponents were monoplanes, the Japanese Mitsubishi A5M Claude (the Zero's predecessor) and the Nakajima Type 97 Nate.
The I-16 in Nationalist China colors
Although neither of these (i.e. Japanese) aircraft had retractable landing gear, they were more maneuverable, and thus more closely competitive. During the Soviet Union's bitter 1939-1940 Winter War with Finland, the Polikarpov I-16 was less successful against the Italian-built Fiat G.50s and Dutch-built Fokker D XXIs.
A two-seater trainer version of the I-16, UTI-4 captured by Finnish Army in 1941. Redesignated UT-1, its is preserved at aviation museum in Helsinki.
When the Germans invaded the Soviet Union in June 1941, the Ishak (Little Donkey or a Beast of Burden, if you wish) was semi-obsolescent but still comprised 26 per cent of the Red fighter force. In the Navy, their share was much higher. Many were shot down or destroyed at the airfields. But in the hands of a capable pilot, the I-16 could still surprise even an experienced Luftwaffe flier.
I also recommend a longer article published on the Aviation History website.
P.S. See 'em fly:
And in 2011: