03/31/2010. The Dr.I was essentially a D.V fuselage, tail surfaces and landing gear married to three pairs of wings, and flown in the summer of 1917 for comparison trials with the standard biplane. Powered by an 180 hp Daimler D IIIa six-cylinder liquid-cooled in-line engine, the Dr.I proved to offer no advantage over the D.V, and progressed no further than prototype evaluation. Armament consisted of the usual pair of 0.312 in (7.92 mm) Spandau machine guns. It had a span of 28 ft 6.5 in (8.70 m) and a length of 24 ft 0.62 in (7.33 m).