Riesenflugzeug

A Riesenflugzeug (plural Riesenflugzeuge, German for "giant aircraft"), sometimes colloquially referred to in English as an R-plane, was any member of a class of large World War I German bombers, possessing at least three aircraft engines, although usually four or more engines.

These large multi-engine aircraft could fly several hours with larger bomb loads than the smaller Grossflugzeug bombers such as the Gotha G.V.

Some of the earliest Riesenflugzeuge were given G-type designations before being redesignated, but a major distinction was that the requirements for the R-type specified that the engines had to be serviceable in flight.

As a result, designs fell into two groups: The transmission of power from the centrally mounted engines to the remote, most often wing-mounted propellers proved troublesome in practice, and most operational examples of Riesenflugzeug-class aircraft were of the second type, as with the all-direct-drive Zeppelin-Staaken R.VI.

The Idflieg (Inspektion der Fliegertruppen (Inspection of the Air Force), the German Army department responsible for military aviation), assigned the letter R to this type of aircraft, which would then be followed by a period and a Roman numeral type number.