Wwii soviet fighter-biplane (winter version)
the improved version of i-15 fighter was the i-15bis. Its main differences were normal wing centre section and naca type engine cowling. Serial production of i-15bis began in 1937 and conti-nued to 1939. I-15bis were supplied to spanish republic (there they became nicknamed super chatos) and china. These fighters took part in air battles over khalhin-gol river, during soviet-finnish war (1939-1940). In the early stage of war in the soviet-german front i-15bis biplanes were obsolete but used as fighters and ground attack aircraft