Aeronautical Division, Signal Corps (1 August 1907 -- 18 July 1914) Aviation Section, Signal Corps (18 July 1914 -- 20 May 1918 Division of Military Aeronautics (20 May 1918 -- 24 May 1918) Air Service, U.S. Army (24 May 1918 -- 2 July 1926) U.S. Army Air Corps (2 July 1926 -- 20 June 1941) * U.S. Army Air Forces (20 June 1941 -- 17 September 1947) * *
when did army air corps become air force
20 June 1941 20 June 1941