WWII Soviet Fighter
One of the first serial monoplane fighter aircraft with retractable landing gear was the I-16, developed in the N.N. Polikarpov Design Bureau.
The maiden flight was in December 30, 1934 «Type 24» modification with M-63 engine and reinforced landing gear was in production in 1939-1940.
In the summer of 1941 I-16 fighters were the basis of Soviet Fighter Aviation. I-16 fighters were used in combat until mid 1943.