Douglas DC-4

The Douglas DC-4 was a four-engined piston airliner produced by the Douglas Aircraft Company. The name had first been used for a 52-seat prototype of 1935, later called the DC-4E, which airlines rejected as too inefficient and unreliable. Douglas then drew up a smaller and simpler design with Pratt and Whitney Twin Wasp engines and a single tail fin. When the United States entered the war in December 1941 the Army Air Forces took over the orders as the C-54 Skymaster, whose first example flew on 14 February 1942. In all, 1,163 military C-54 and R5D aircraft were built, plus another 79 DC-4 airliners after the war, and many airlines flew the type worldwide from 1945.