Polikarpov I-16 fighter plane (Unusual Aircraft Collection)

The Polikarpov I-16 was a very innovative fighter which first flew at the end of 1933.   It was the first cantilevered monoplane fighter with retractable undercarriage, which greatly increased the top speed, making it the world's fastest fighter of the time.   Although some people thought it was based on the American P-26 "Peashooter", it was in fact an original design.

About 500 I-16s fought with the Republicans during the Spanish civil war, completely dominating the air until the Messerschmitt Bf 109 appeared.   When Germany invaded Russia in 1941, about two-thirds of the Russian fighter force still consisted of the I-16, even though the Russians had already realized that it was at the end of its development potential.   The I-16 was still capable of operating against the early-model Bf 109E "Emil" at low altitudes, but by 1943 it had been replaced by more modern aircraft.