The first Riesenflugzeug built was the VGO.I flying in April 1915, using three engines; two pusher and one tractor, with a 42 meters span, four-bay interplane strut layout for its slightly swept-back leading edge biplane configuration, maintained throughout the entire Zeppelin-Staaken R-series of aircraft during World War I. The VGO.I was built for the Marine-Fliegerabteilung (Imperial German naval Air service) and served on the Eastern Front Later modified with two extra engines, it crashed during tests at Staaken.