 Zeppelin-Staaken R.VI

The Zeppelin-Staaken R.VI was a four-engined German biplane strategic bomber of World War I, and the only "Riesenflugzeug" ("giant aircraft") design built in any quantity.The R.VI was the most numerous of the R-bombers built by Germany, and also among the earliest closed-cockpit military aircraft (the first being the Russian Sikorsky Ilya Muromets).