Douglas produced a succession of piston-engined aircraft (DC-2, DC-3, DC-4, DC-5, DC-6, and DC-7) through the 1930s, 1940s, and 1950s.
Douglas producira unha serie de avións con motores de pistón (DC-2, DC-3, DC-4, DC-5, DC-6 e DC-7) durante os anos 30, 40 e 50.