The Rumpler C.IV was a German single-engine, two-seat reconnaissance biplane. It was a development of C.III with different tail surfaces and using a Mercedes D.IVa engine in place of the C.III's Benz Bz.IV. The Rumpler 6B 2 was a single-seat floatplane fighter variant with a 120 kW (160 hp) Mercedes D.III engine built for the Kaiserliche Marine.
Rumpler C.IV
Rumpler CIV shot down near Châlons-sur-Marne by French ace Hector Garaud.
Surviving Rumpler C.IV as seen in Deutsches Museum
Rumpler C.IV inside visible
The Mercedes D.IVa was a German six-cylinder, water-cooled, inline engine developed in 1917 for use in aircraft and built by Daimler Motoren Gesellschaft (DMG).
Mercedes D.IVa