Original: It was a component of the United States Army , divided functionally by executive order in 1942 into three autonomous forces : the Army Ground Forces , the Services of Supply ( which in 1943 became the Army Service Forces ) , and the AAF .
Simplified: The Air Corps became the Army Air Forces in June 1941 to provide the air arm a greater autonomy in which to expand more efficiently , and to provide a structure for the additional command echelons required by a vastly increased force .