# 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:
* those with the engines mounted centrally inside the fuselage using gearboxes and driveshafts to transfer the power to propellers mounted between the wings, and
* those with conventional powerplant installations mounted in large nacelles or the nose of the aircraft where engineers would be stationed for each group of engines.
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. Seaplanes were denoted by adding a lowercase "s" after the "R" in the designation.
The Riesenflugzeuge were the largest aircraft of World War I. In comparison, the largest equivalent Allied aircraft were the Sikorsky Ilya Muromets with a span of 29.8 m (98 ft), the Caproni Ca.4 with a span of 29.9 m (98 ft), the one-off Felixstowe Fury flying boat with a span of 37.5 m (123 ft) and the Handley Page V/1500 with a span of 38.41 m (126.0 ft). The Riesenflugzeuge that bombed London during the First World War were larger than any of the German bombers in use during the Second World War. The largest built, the Siemens-Schuckert R.VIII of 1918, had a wingspan of 48.0 m (157.5 ft). It was not until sixteen years later that an aircraft with a larger wingspan, the Soviet Tupolev Maksim Gorky eight-engined monoplane, was built with a 63.0 m (206.7 ft) wingspan.
The Riesenflugzeuge were operational from 1915 to 1919 and most of them were built as "one-off" aircraft.

## List of aircraft

| Type | Engines | Span | First flight | Service | Notes | Number built |
| AEG R.I | 4 × 260 hp Mercedes D.IV | 36 m (118 ft 1 in) | 1916 | None | Broke up in flight in 1918 | 1 completed 7 partially built |
| DFW R.I | 4 × 220 hp Mercedes D.IV | 29.5 m (96 ft 9 in) | 1916 | Eastern front | Crashed on 2nd combat flight | 1 |
| DFW R.II | 4 × 260 hp Mercedes D.IVa | 30.06 m (98 ft 7 in) | 1918 | Trainer as unsuitable for combat | | 2 of 6 ordered |
| DFW R.III | 8 × 260 hp Mercedes D.IV | 53.5 m (175 ft 6 in) | n/a | None | Incomplete at end of war, cancelled | None |
| Junkers R.I | 4 × 260 hp Mercedes D.IVa | 35.0 m (114 ft 10 in) | n/a | None | | 1 incomplete |
| LFG Roland R.I | 4 × 1000 hp Maybach Mb.IV | n/a | n/a | None | | Not built |
| Linke-Hofmann R.I | 4 × 260 hp Mercedes D.IVa | 33.2 m (108 ft 11 in) | 1917 | None | First example had 32.02 m (105 ft 1 in) span | 4 |
| Linke-Hofmann R.II | 4 × 260 hp Mercedes D.IVa | 42.16 m (138 ft 4 in) | 1919 | None | Used largest single propeller ever built, some 6.9 meters in diameter | 2 |
| Mannesmann Giant Triplane | 10 × unk. engines | 50.3 m (165 ft 0 in) | n/a | None | Cancelled incomplete | None |
| Schütte-Lanz R.I | 6 × 300 hp Basse und Selve BuS.IVa | 44.0 m (144 ft 4 in) | n/a | None | Design study only | None |
| Siemens-Schuckert Forssman R | 2 × 110 hp Mercedes D.III & 2 × 220 hp Mercedes D.IVa | 24.0 m (78 ft 9 in) | 1915 | Trainer | After several rebuilds it was accepted by the military in 1916. Scrapped after breaking in two. | 1 |
| Siemens-Schuckert R.I | 3 × 150 hp Benz Bz.III | 28.0 m (91 ft 10 in) | 1915 | Eastern front & training | | 1 |
| Siemens-Schuckert R.II | 3 × 260 hp Mercedes D.IVa | 38.0 m (124 ft 8 in) | 1915 | Training | Span increased | 1 |
| Siemens-Schuckert R.III | 3 × 220 hp Benz Bz.IV | 34.33 m (112 ft 8 in) | 1915 | Training | | 1 |
| Siemens-Schuckert R.IV | 3 × 220 hp Benz Bz.IV | 37.6 m (123 ft 4 in) | 1916 | Training | Span increased | 1 |
| Siemens-Schuckert R.V | 3 × 220 hp Benz Bz.IV | 34.33 m (112 ft 8 in) | 1916 | Eastern front | Span increased | 1 |
| Siemens-Schuckert R.VI | 3 × 220 hp Benz Bz.IV | 33.36 m (109 ft 5 in) | 1916 | Eastern front | Span increased | 1 |
| Siemens-Schuckert R.VII | 3 × 260 hp Mercedes D.IVa | 38.44 m (126 ft 1 in) | 1917 | Eastern front | | 1 |
| Siemens-Schuckert R.VIII | 6 × 300 hp Basse und Selve BuS.IVa | 48.0 m (157 ft 6 in) | n/a | None | | 2 (one unfinished) |
| Siemens-Schuckert R.IX | 8 × 300 hp Basse und Selve BuS.IVa | n/a | n/a | None | Design study only | None |
| Zeppelin-Lindau Rs.I | 3 × 240 hp Maybach Mb.IV | 43.5 m (142 ft 9 in) | n/a | None | Wrecked unflown, 1915. Flying-boat | 1 |
| Zeppelin-Lindau Rs.II | 3 × 240 hp Maybach Mb.IV | 33.2 m (108 ft 11 in) | 1916 | None | Flying boat | 1 |
| Zeppelin-Lindau Rs.III | 3 × 245 hp Maybach Mb.IVa | 37.0 m (121 ft 5 in) | 1917 | Evaluation | Flying boat | 1 |
| Zeppelin-Lindau Rs.IV | 4 × 245 hp Maybach Mb.IVa | 37 m (121 ft 5 in) | 1918 | None | Flying boat | 1 |
| Zeppelin-Staaken VGO.I | 3 × 240 hp Maybach HS or 5 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5 in) | 1915 | Kaiserliche Marine | Built at Versuchsbau Gotha Ost | 1 |
| Zeppelin-Staaken VGO.II | 3 × 240 hp Maybach HS | 42.2 m (138 ft 5 in) | 1915 | Eastern front & trainer | | 1 |
| Zeppelin-Staaken VGO.III | 6 × 160 hp Mercedes D.III | 42.2 m (138 ft 5 in) | 1916 | Eastern front | | 1 |
| Zeppelin-Staaken R.IV | 2 × 160 hp Mercedes D.III & 4 × 220 hp Benz Bz.IV | 42.2 m (138 ft 5 in) | 1916 | Eastern front & Western front | | 1 |
| Zeppelin-Staaken R.V | 5 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5 in) | 1916 | Western front | | 1 |
| Zeppelin-Staaken R.VI | 4 × 260 hp Mercedes D.IVa | 42.2 m (138 ft 5 in) | 1916 | Western front | | 18 |
| Zeppelin-Staaken R.VII | 2 × 160 hp Mercedes D.III & 4 × 220 hp Benz Bz.IV | 42.2 m (138 ft 5 in) | 1917 | None | Wrecked during flight to the front. | 1 |
| Zeppelin-Staaken R.VIII | 8 × 260 hp Mercedes D.IVa or 8 × 245 hp Maybach Mb.IVa | 55 m (180 ft 5 in) | 1918 | None | Unfinished | 1 incomplete |
| Zeppelin-Staaken R.IX | 8 × 260 hp Mercedes D.IVa or 8 × 245 hp Maybach Mb.IVa | 55 m (180 ft 5 in) | 1918 | None | Unfinished | 1 incomplete |
| Zeppelin-Staaken R.XIV | 5 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5 in) | 1918 | Western front | | 3 |
| Zeppelin-Staaken R.XIVa | 5 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5.5in) | ? | Post-war | Seized while smuggling | 1 |
| Zeppelin-Staaken R.XV | 5 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5.5in) | 1918 | Western front | | 2 |
| Zeppelin-Staaken R.XVI | 2 × 530 hp Benz Bz.VI & 2 × 220 hp Benz Bz.IV | 42.2 m (138 ft 5 in) | 1918 | Airliner | Two completed, 3rd unfinished | 3 (one unfinished) |
| Zeppelin-Staaken L | 4 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5 in) | ? | None | Floatplane variant. Wrecked in trials. | 1 |
| Zeppelin-Staaken Type 8301 | 4 × 245 hp Maybach Mb.IVa | 42.2 m (138 ft 5 in) | ? | floatplane airliner | 3 built for Kaiserliche Marine | 3 |