American military aviator Claire Chennault became an advisor to the Chinese Air Force during WWII in 1937. In 1941, he formed the American Volunteer Group, or AVG, and led the U.S. volunteer pilots, who were praised as "Flying Tigers" by the locals, to their first victory in Kunming. In the years that followed, this formidable squadron regularly thwarted Japanese air attacks, protecting areas behind China's front lines.