The 21st Airship Group is a disbanded unit of the United States Army Air Corps. It was last assigned to the 3d Wing at Scott Field, Illinois. It was disbanded on 27 May 1939.A predecessor of the group served on the Western Front in France during World War I.For most of the period between the two World Wars, the group was the only active lighter-than-air headquarters in the United States Army Air Service and, later, the United States Army Air Corps.