 In 1936 Zemke's friends convinced him to try out for pilot training in the U.S. Army Air Corps.He was accepted as an aviation cadet, gained his pilot's wings and commissions at Randolph Field, then attended the pursuit pilot course at Kelly Field, Texas, in 1937, becoming a Curtiss P-40 pilot with the 36th Pursuit Squadron at Langley Field, Virginia.In 1940, Zemke was sent to England as a combat observer with the Royal Air Force, studying the tactics of both the RAF and the Luftwaffe, observations that he would use later when the United States entered the war.