On Nov. 30, 1928, Douglas incorporated his business as the Douglas Aircraft Co. Inc. and moved to the completed building in Santa Monica in 1929. In its new facilities, the Douglas Aircraft Co. continued to make observation biplanes and built its first twin-engine aircraft, the T2D-1 torpedo bomber. It also produced a small commercial amphibian, the Sinbad that led to the successful military Dolphin; the famous Douglas Commercial series aircraft DC-1, DC-2, and DC-3; the DC-5 and the B-18 Bolo bomber.