Albatros D.I. (photo)

In 1916, Albatros Werke produced the remarkably advanced Albatros D.I. It featured a streamlined semi-monocoque fuselage, with an almost fully-enclosed 160-horsepower in-line Mercedes engine, and the propeller spinner neatly contoured into the nose of the fuselage. A sesquiplane version with narrow-chord lower wings, designated the D-III, was introduced early in 1917, and served with great success. The Albatros D.V model was fitted with a more powerful 180-horsepower engine, but was plagued by a rash of wing failures. The wings were strengthened, resulting in a re-designation, the D.Va. Unfortunately, the necessary strengthening increased the weight and negated the performance advantage of the new engine.