Because he was too young to enter flight training in the United States, James Luma joined the Royal Canadian Air Force and sent to England. He was transferred to the U.S. Army Air Forces but was attached to RCAF No. 418 Squadron to continue training in night-fighting techniques, becoming an ACE credited with shooting down 5 enemy aircraft in aerial combat. In 1944, he was finally transferred to a U.S. Army Air Forces Squadron, serving until July 1945.