The AEG D.I was a biplanefighter of World War I. Three prototypes were ordered, but after the first two were involved in serious crashes, one of which killed flying ace Walter Höhndorf on September 5, 1917, development was cancelled. A triplane version was built as the Dr.I. The second and third prototypes differed little from the first except in detail.[1]
Wagner, Ray and Nowarra, Heinz. German Combat Planes: A Comprehensive Survey and History of the Development of German Military Aircraft from 1914 to 1945. New York: Doubleday, 1971.