Zeppelin - Staaken R . VI The Zeppelin - Staaken R . VI was a four - engined German biplane strategic bomber of World War I , and the only so - called " Riesenflugzeug " ( " giant aircraft " ) design built in any quantity . 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 . In September 1914 , at the start of World War I , 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 42 . 2 meter ( 138 ft 5½ in ) 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 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 , R . VI , 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 R - plane 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 19 , 100 feet ( 5 , 800 m ) . 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 130 E 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 . Operational service . The R . VI equipped two " Luftstreitkräfte " ( Imperial German Army Air Service ) units , " Riesenflugzeug - Abteilung " ( Rfa ) 500 and Rfa 501 , with the first delivered June 28 , 1917 . The units first served on the Eastern Front , based at Alt - Auz and Vilua in Kurland until August 1917 . Almost all missions were flown at night with bomb loads , operating between altitude . Missions were of three to five hours ' duration . Rfa 501 was transferred to Ghent , Belgium , for operations against both France and Great Britain , arriving September 22 , 1917 , at St . Denis - Westrem ( Sint - Denijs - Westrem ) airdrome . Rfa 501 later moved its base to Scheldewindeke airdrome south of group headquarters at Gontrode , while Rfa 500 was based at Castinne , France , with its primary targets French airfields and ports . Rfa 501 , with an average of five R . VI ' s available for missions , conducted 11 raids on Great Britain between September 28 , 1917 , and May 20 , 1918 , dropping of bombs in 30 sorties . Aircraft flew individually to their targets on moonlit nights , requesting directional bearings by radio after takeoff , then using the River Thames as a navigational landmark . Missions on the round trip lasted seven hours . None were lost in combat over Great Britain ( compared to 28 Gotha G bombers shot down over England ) , but two crashed returning to base in the dark . Four R . VI ' s were shot down in combat ( one - third of the operational inventory ) , with six others destroyed in crashes , of the 13 commissioned during the war . Six of the 18 eventually built survived the war or were completed after the armistice . Discovered crash site . Very little remains of these giant bombers , although nearly a century after the end of World War I amateur historians of the " Poelcapelle 1917 Association vzw " working in Poelkapelle , northeast of Ypres , identified a wreck that was found in 1981 by Daniel Parrein , a local farmer who was plowing his land . For a while it was thought that the wreck was that of French ace Georges Guynemer ' s SPAD S . XIII ; however that was discounted when repair tools were found at the site , and further research pointed that the engine was a Mercedes D . IVa , possibly of a Gotha G bomber . A comparison of recovered parts was inconclusive , since the parts were common to a number of aircraft other than the Gotha G . In 2007 the researchers , Piet Steen with some help of Johan Vanbeselaere , finally made a conclusive ID after visiting one of the very few partial specimens ( the distinctive engine nacelles ) in a Krakow air museum . With the help of the Polish aviation historians , parts were identified as those of Zeppelin - Staaken R . VI R . 34 / 16 , which crashed on 21 April 1918 after a mission against the British Royal Air Force field at Saint - Omer , France . The R . VI was shot down , apparently by anti - aircraft fire of the British 2nd Army , while trying to cross the front line , killing all seven crew members . Three R . XIVs were built , serialled R 43 / 16 to R 45 / 16 , of which R 43 / 16 was shot down by Capt . Yaille of No . 151 Squadron RAF .