The Douglas DT bomber was the Douglas Aircraft Company's first military contract, forging a link between the company and the United States Navy. Navy Contract No. 53305 of April 1, 1921, required only 18 pages to set out the specifications that resulted in the purchase of three DT (D for Douglas, T for torpedo) folding-wing aircraft. First flight was in November 1921 and production continued until 1929. The DT operated off the U.S. Navy's first aircraft carrier, USS Langley, from land bases, and from seaplane tenders. Several were flown by the Marine Corps.