Albatros D.IX was a German prototype single-seat fighter built in early 1918. It differed from previous marks by using a simplified fuselage with a flat bottom and slab sides. The wings and tail were similar to those of the Albatros D.VII. Power was provided by a 130 kW (170 hp) Mercedes D.IIIa engine. The D.IX was armed with twin synchronised 7.92 mm (0.312 in) LMG 08/15 machine guns. The prototype exhibited disappointing performance and the project was discontinued.