After moving to the Netherlands, Fokker continued to develop fighter aircraft. Despite the fact that the V. IX and D.X projects were not successful, the designer Reinold Platz (Reinhold Platz) in 1923 began work on a new aircraft D.XI
Built in 1921, the D. IX fighter became the basis for the D. XI. It was a single-seat sesquiplane with a non-retractable landing gear. The 300 hp Hispano-Suiza 8 Fb engine could reach speeds of up to 225 km / h. The flight range was 440 km. Armament — 2 × 7.7 mm machine guns.
According to its characteristics, the Fokker D. XI was one of the best fighters of its time. But financial problems prevented the Dutch government from ordering these planes. Therefore, all 117 produced D. XI fighters went for export — to the USSR, Romania, Spain, Switzerland, Argentina and the United States.