Fokker D.IV

The Fokker D.IV was a biplane fighter designed by Fokker-Flugzeugwerke for the Imperial German Air Service during the First World War. It was a development of the D.I with a more powerful 160 horsepower Mercedes D.III engine, two fixed forward-firing 7.92 mm machine guns, and ailerons instead of the wing warping of earlier Fokker fighters. Structural problems caused by poor-quality components and workmanship at the factory limited it, and a ban on front-line use of Fokker aircraft followed on 6 December 1916 after a series of structural failures. Only one aircraft is known to have served in a front-line unit; the rest went to training and home defence, and Sweden bought four.