USAF EDITTTTT Description of the USAF : The United States Air Force (USAF) is the air service branch of the United States Armed Forces.[15] It is a part of the United States Department of Defense and is one of the six armed forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the Air Force was established by transfer of personnel from the Army Air Forces with the enactment of the National Secu