Zeppelin-Staaken R.IV

The Zeppelin-Staaken R.IV was a heavy bomber built in Germany in 1916 to the Imperial German Army specification for Riesenflugzeuge, or giant aircraft, and it was the first such design by Zeppelin-Staaken to receive the R designation. Based on the VGO.I, VGO.II and VGO.III, it adopted the VGO.III coupled-engine layout, with pairs of engines joined by gearboxes and clutches driving single propellers: two Mercedes D.III in the nose and four Benz Bz.IV in the nacelles. It first flew on 16 August 1916 and was accepted by the Army Air Service on 5 May 1917. It served briefly on the Eastern Front, raiding Valmiera and Saaremaa, and then with Rfa 501 near Ghent, from where it dropped 25,000 kilograms of bombs on London, Chelmsford and other targets until the end of the war. On the night of 16 and 17 February 1918 it survived a collision with a balloon apron over London with very minor damage, and it was displayed in Kassel and other German cities in 1919.