[1] Developed as a private venture by DFW, it was a large biplane of conventional configuration with four engines mounted inside the fuselage, powering propellers on the wings via transmission shafts - two mounted tractor-fashion on the leading edge of the upper wing, and two mounted pusher-fashion on the trailing edge of the lower wing.
[2] After factory tests proved promising, military acceptance trials commenced on 19 October 1916 and led to the aircraft being purchased for the Luftstreitkräfte.
[2] Following these modifications, R.I (R 11/15) was deployed on the Eastern front with Rfa 500 at Alt-Auz, April 1917 to September 1917, from whence it raided Riga during the summer of 1917.
On its second combat mission, the R.I crashed due to the failure of two engines, and was destroyed.
Data from The German Giants[2]General characteristics Performance Armament