The D prototype was offered to the US Army Air Service at the end of 1918.

It was a two-bay biplane of all-wood construction, covered with fabric.

The pilot of the first flight test, Clarence B. Coombs, gave it a positive evaluation: "This aircraft performs better than the Sopwith Camel and Snipe, the Thomas-Morse, the Nieuport and Morane Parasol, the Spad and S.V.A.

Curtiss Aircraft entered the lowest bid and built the fighter, modifying it slightly with a wider wingspan and redesigned ailerons.

Data from: Flight: The Aircraft Engineer & Airships, "Some 'Orenco' (U.S.A) Aeroplanes", 1 April 1920, pp. 363–366.