One of the first 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 10” modification with 4 MG armament and M-25 engine was in production in 1937-1939. It were produced 934 I-16 type 10.
Those fighters took part in Khalkhin Gol conflict and Soviet-Finnish war.
In the summer of 1941 I-16 fighters were the basis of Soviet Fighter Aviation. They participated in air battles in all sectors of the Soviet-German Front.