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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.〔Gray, P and Thetford, O ''German Aircraft of the First World War'' 1970 Putnam London 0 85177 809 7〕 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). The bomber was reputedly the largest wooden aircraft to be produced in any quantity during World War I, with only the Siemens-Schuckert R.VIII prototype bomber of 1918–1919 being larger, with the Staaken R.VI's wingspan of nearly equaling that of the World War II Boeing B-29 Superfortress, and somewhat less than the span of the Siemens-Schuckert R.VIII.〔 ==Design and development== (詳細はFerdinand von Zeppelin visualised the concept of a ''Riesenflugzeug'' (R) bomber, to be larger than the then-nascent Friedel-Ursinus twin-engined military aircraft. Using engineers from the Robert Bosch GmbH, he created the ''Versuchsbau Gotha-Ost'' (VGO) consortium in a rented hangar at the Gotha factory. Alexander Baumann became his chief engineer, although later the team included other noted engineers including Zeppelin's associate Claudius Dornier, the 1915 pioneer of all-metal aircraft construction in Hugo Junkers and Baumann's protogé Adolph Rohrbach. Almost all of these Zeppelin-Staaken ''Riesenflugzeug'' designs used some variation of either pusher configuration and/or push-pull configuration in their engine layout, orientation and placement of their powerplants. The first ''Riesenflugzeug'' built was the VGO.I flying in April 1915, using three engines; two pusher and one tractor, with a 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. A similar machine, the VGO.II was also used on the Eastern Front.〔 Baumann was an early expert in light-weight construction techniques and placed the four engines in nacelles mounted between the upper and lower wing decks to distribute the loads to save weight in the wing spars.〔 The next aircraft, the VGO.III was a six-engined design〔The VGO.III was sometimes unofficially called the R.III but the official R-designations began with R.IV, to avoid confusion with the earlier VGO designations.〕 The 160 hp Maybach engines were paired to drive the three propellers. It served with ''Riesenflugzeug Abteilung'' (Rfa) 500.〔 In 1916 VGO moved to the Berlin suburb of Staaken, to take advantage of the vast Zeppelin sheds there. The successor to the VGO III became the Staaken R.IV (IdFlieg number R.12/15), the only "one-off" Zeppelin-Staaken R-type to survive World War I, powered by a total of six engines, driving three propellers: a tractor configuration system in the nose and two pusher-mount nacelle mounts between the wings. By the autumn of 1916, Staaken was completing its R.V, the R.VI prototype, and R.VII versions of the same design, and Idflieg selected the R.VI for series production over the 6-engined R.IV and other Riesenflugzeug designs, primarily those of Siemens-Schuckertwerke AG.〔 With four direct-drive engines in a tandem push-pull arrangement, and a fully enclosed cockpit, the R.VI design required none of the complex gearboxes of other R-types. Each R.VI bomber cost 557,000 marks and required the support of a 50-man ground crew. The R.VI required a complex 18-wheel undercarriage consisting of twin nosewheels and a quartet of four-wheeled groupings for its main gear to support its weight, and carried two mechanics in flight, seated between the engines in open niches cut in the center of each nacelle. The bombs were carried in an internal bomb bay located under the central fuel tanks, with three racks each capable of holding seven bombs. The R.VI was capable of carrying the 1000 kg PuW bomb.〔 Although designed by Versuchsbau, because of the scope of the project, the production R.VI's were manufactured by other firms: seven by Schütte-Lanz〔 using sheds at Flugzeugwerft GmbH Staaken, Berlin; six by Automobil und Aviatik A.G. (Aviatik)〔 (the original order was for three); and three by Albatros Flugzeugwerke. 13 of the production models were commissioned into service before the armistice and saw action.〔 One R.VI was as a float-equipped seaplane for the Marine-Fliegerabteilung (Imperial German Naval Air Service), with the designation Type L and s/n 1432, using Maybach engines. After the first flight on 5 September 1917 the Type "L" crashed during testing on June 3, 1918. The Type 8301, of which four were ordered and three delivered, was developed from the R.VI by elevating the fuselage above the lower wing for greater water clearance, eliminating the bomb bays, and enclosing the open gun position on the nose.〔 R.VI serial number R.30/16 was the earliest known supercharged aircraft to fly, with a fifth engine - a Mercedes D.II - installed in the central fuselage, driving a Brown-Boveri four-stage supercharger at some 6,000 rpm. This enabled the R.30/16 to climb to an altitude of . The idea of supercharging an aircraft's propeller-driving piston engines with an extra powerplant used solely to power a supercharger was not attempted again by Germany until later in World War II, when the Henschel Hs 130E revived the idea as the ''Höhen-Zentrale-Anlage'' system. The R.30/16 aircraft was later fitted with four examples of one of the first forms of variable-pitch propellers, believed to have been ground-adjustable only.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Zeppelin-Staaken R.VI」の詳細全文を読む スポンサード リンク
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