Similar to the D.II, the D.I was an
unstaggered single-bay, or
Einstielig equal-span biplane. The upper fuselage was initially parallel with the upper wing and was fitted with the
Mercedes D.I six-cylinder water-cooled engine. Control was achieved using
wing-warping. The wings were also tested in twin-bay
(Zweistielig) form. To improve visibility, the center section was cut back and the wings were slightly staggered and the top wing raised slightly. These improvements were retained, and the airplane was ordered into production with an
Mercedes D.II inline engine and a single synchronized 7.92 mm (.312 in)
lMG 08 machine gun. The Austro-Hungarian B.IIIs, serialled 04.11 to 04.27, retained the Mercedes D.I engine, and some were armed with a free-firing
Schwarzlose MG M.07/12 machine gun mounted above the centre-section. ==Operational history==