At the outset of war, China primarily relied on foreign countries for its military aircraft, but did produce about 100 Hawk II/III fighter-bombers at the Hangzhou-based CAMCO plant. 15 Chinese-American pilots formed the first unofficial volunteer group of pilots and joined front-line air units in China beginning as early as 1932 in anticipation of imminent war with Imperial Japan. These volunteers included future ace-fighter pilots Art Chin and John Wong. Both the Soviet Union and the United States came to China's aid by supplying aircraft and providing training to Chinese pilots. Volunteers from the United States and the Soviet Union also participated in China's war against Japan, the most remarkable among them being the American Volunteer Group, better known as the Flying Tigers, which u