An American de Havilland converted from a single to a multi-engined machine. The engines are two six-cylindered Libertys, one of which is capable of maintaining the machine in flight. It is being used, in conjunction with the Martin "bombers" for mail-carrying, and is said to be nice and easy on the controls.
Test pilot Jack Foote demonstrating a Twin-D.H., November 1919. Efforts to increase the D.H.4’s payload to 800lb led the LWF Company to replace the 400 h.p. Liberty Twelve with twin 200 h.p. Hall Scotts, then 180 h.p. Hissos (shown here). Twenty were built for the Post Office Department, all of which had Liberty Sixes of 240 h.p. Twin D.H.s served on the New York-Cleveland, Cleveland-Chicago and St Louis-Twin Cities Divisions until 1922.