02/28/2016. Remarks by Johan Visschedijk: "During the war, Dayton Wright received contracts for 5,000 DH-4s following modification of a pattern aircraft sent from Britain to accept the Liberty 12 engine and American 0.30 in (7.62 mm) Marlin machine guns. The final total of DH-4s delivered was 3,098, the rest being cancelled. In addition, there were substantial numbers remodelled or converted to DH-4A or DH-4B standard and 155 were transferred to the USN and USMC with the designation O2B.
Dayton Wright also built the DH-4R, an unarmed advanced trainer conversion with dual controls, modified rear decking, and the gunner's position modified to an instructor's position. At least one Nine Hour Cruiser was completed, a DH-4 (s/n 30130) with an enlarged fuel tank positioned directly over the landing gear, aft of the Liberty engine and ahead of the two open cockpits. With double the normal endurance, non-stop flights were claimed possible between New York and Chicago. The D.W.H. 4 Blue Bird was a dual-control trainer version, with the same modifications, produced in small numbers for the USAAS.
The first postwar civil conversion offered was the DH-4K Honeymoon Express, a three-seat sport conversion of a DH-4B with a 1ft longer fuselage, displayed at the Aeronautical Exhibition, Madison Square Garden, New York City during March 1-15, 1919.
