DFW C . V The DFW C . IV , DFW C . V , DFW C . VI , and DFW F37 were a family of German reconnaissance aircraft first used in 1916 in World War I . They were conventionally configured biplanes with unequal - span unstaggered wings and seating for the pilot and observer in tandem , open cockpits . Like the DFW C . II before them , these aircraft seated the gunner to the rear and armed him with a machine gun on a ring mount . Compared to preceding B - and C - class designs by DFW , however , the aerodynamics of the fuselage were more refined , and when coupled with more powerful engines , resulted in a machine with excellent performance . Design and development . The C . IV had a single - bay wing cellule and was powered by a Benz Bz . III . It was soon replaced in production by the definitive C . V with a two - bay wing cellule and either a C . III N . A . G . or Benz Bz . IV . Predictably , the more powerful Benz engine gave significantly better performance . The C . V ' s main designer was Heinrich Oelerich , and it was produced in larger numbers than any other German aircraft during World War I . About 2000 were manufactured by DFW and about 1250 licence maufactured by Aviatik ( as the DFW C . V ( Av ) or Aviatik C . VI ) , Halberstadt , LVG , and Schütte - Lanz . A further development was the C . VI , a sturdier aircraft with balances added to the ailerons . Only a single example of this was built , but it was followed by three aircraft designated F37 in the closing stages of the war , which may have received the Idflieg designation DFW C . VII , though this is not certain . Following the war , the DFW F37 was fitted with the BMW IV engine , and in this configuration broke the world altitude record in 1919 , reaching a height of . However , since this flight was in breach of the Armistice , it was not recognised by the FAI . After this exploit , this F37 had its original Benz engine restored , and was converted into a passenger " limousine " by the addition of a richly upholstered interior and a canopy to enclose it . Now designated the DFW P1 Limousine , it could carry three passengers and was demonstrated by DFW at the ELTA exhibition in Amsterdam in 1919 , flying passengers . Description . It was a biplane of mixed , mostly wooden construction . A fuselage of a wooden frame , covered with plywood . Two - spar rectangular wooden wings , canvas covered . Upper wing of slightly greater span , with extended ends with ailerons . Tail of metal frame , covered with canvas . Straight engine in a fuselage nose , with a chimney - like exhaust pipe ( LVG - produced planes had horizontal exhaust pipe ) . Engine was initially covered with an aerodynamic cover , but it was often abandoned . Two - blade wooden propeller , 2 . 8 m diameter . Water radiators on both fuselage sides , later water radiator before upper wing . Fixed conventional landing gear , with a straight common axle and a rear skid . Operational history . The C . V and its related designs were used as a multi role combat aircraft , for reconnaissance , observation , and bombing by Germany and Bulgaria during World War I . Six aircraft were delivered to Bulgaria in 1917 . In the hands of a skilled pilot it could outmaneuver most allied fighters of the period . It remained in service until early 1918 though 600 were still in use by the Armistice of 11 November 1918 . Most were thereafter scrapped according to the Treaty of Versailles in 1919 . Poland seized 11 aircraft in 1919 and manufactured further 13 in 1920 from seized parts . Several other C . Vs were bought in 1920 . They were used by the Polish Air Force in Polish - Soviet war . Two were used post - war in Finland , four in the Netherlands , two in Switzerland and a number in Estonia . Eight aircraft were converted to civilian ones and used by " Deutsche Luft Rederei " . Seven copies were built by the " Darzhavna Aeroplane Robotilnitsa " ( Bulgarian state aircraft workshops ) in 1925 as the DAR Uzunov - 1 ( DAR U - 1 ) and used as a trainer for Bulgaria ' s secret air force . Only one fuselage of a C . V ( Av ) survives in the Polish Aviation Museum in Kraków . < br > Operators . " Post - War Operators : "