The nearly-destoryed Chinese Army needed to be rebuilt with great emergency and the answer was from the Soviet Union. October 1937, about 450 volunteer pilots and technical personnel arrived in China by train and brought 225 Russia-made planes: 155 fighters, 62 bombers and 8 trainers.

The Russia-made I-16 fighter planes had retractable landing gears and two 7.6 cm machine guns on the wings and it was the fastest fighter in Asia then. Anther exciting feature of I-16 was the 9 cm thick armor behind the pilot seat -- a device which was adopted by US Army after 1941 and never achieved by Japanese planes even when the war was nearly ended.

November 22, 1937, the first shot-down record of I-16 was done by the Russian Capton Prokoviev, who led 23 I-16 planes to engage the A5Ms and shot down several Japanese fighters.