Fokker D.XII

The Fokker D.XII was a Dutch single-seat, single-engine fighter designed to an American specification that called for the Curtiss D-12 engine, the requirement designated PW-7. It owed its existence to the Fokker D.XI, which had won an order for three from the US Army Air Service in the same competition, though the two aircraft had no design overlap. The D.XII began as a single-bay sesquiplane, first with the 224 kW Hispano-Suiza 8F V-eight and then with the specified 328 kW Curtiss D-12 water-cooled V-twelve, and made its first flight under Curtiss power on 21 August 1924. Flight testing led to major changes, including an upper wing of constant chord, a lower wing of nearly equal span, stronger N-form interplane struts and a reshaped rudder, and two more aircraft were built with these modifications. The US Army Air Service still did not like it and bought none of the three, so further development was abandoned.