During the First World War, German aircraft officially adopted for military service were allocated a designation that included (1) the name of the manufacturer, (2) a function or "class" letter, and (3) a
Roman numeral. The three-part designation was needed for a unique designation to simplify logistics support of the many types of aircraft in operation – especially as squadrons more often than not were equipped with several different types. The designation system evolved during the war. Initially, all military aircraft were classed as "A" (monoplanes) or "B" (biplanes). The new "C" class of armed (two seat) biplane began to replace the "B" class aircraft as reconnaissance machines in 1915, the Bs continuing to be built, but as trainers. The "E" class of armed monoplane was also introduced in 1915 – the other classes were added later as new aircraft types were introduced. For most of the war 'D' was only used for biplane fighters, 'E' for monoplane fighters and 'Dr' for triplane fighters, however by the end of the war the 'D' designation was used for all single-seat fighters, including monoplanes (and, in theory at least, triplanes). :
A – Unarmed reconnaissance monoplane aircraft (for example the
Rumpler Taube and
Fokker M.5) :
B – Unarmed two-seat biplane, with the observer seated in front of the pilot. :
C – Armed two-seat biplane, with the observer (usually) seated to the rear of the pilot. :
CL – Light two-seater (primarily from
Halberstadt and
Hannover), initially intended as escort fighters – by 1917–18, mainly used for ground attack. :
D – – single-seat, armed biplane but later any fighter – for instance the
Fokker E.V monoplane was renamed the D.VIII. :
Dr – – triplane fighter (twin service test Fokker triplanes initially
"F") :
E – – armed monoplane – initially included monoplane two-seaters. New monoplane types at the end of the war designated as "D" (single seat) or "CL" (two seat). :
G – – Large twin-engined types, mainly bombers (initially "K") :
GL – Lighter, faster twin-engined bombers, intended for use by day. :
J – – Fuel tanks, pilot, and (usually) the engine protected by armour plate, reducing vulnerability to ground fire. Used for low-level work, especially ground attack. :
N – "C" type aircraft adapted for night bombing – apart from night flying equipment they were fitted with wings of greater span to increase bomb load. :
R – – "Giant" aircraft – at least three, up to four to six engines – all serviceable in flight. Most manufacturers also had their own numbering systems quite separate from the official military designations for their products. These sometimes cause confusion – for instance the military "J" series of armored aircraft designs was quite distinct from the
Junkers aviation firm's own "J" factory type designations – the factory designation of the (military)
Junkers J.I armored, all-metal sesquiplane, for example, was the Junkers J.4. The "M" (for "Militär" or military) and "V" (for "Versuchs" or experimental, according to some source initially meant a or "unbraced" airframe) designations of the Fokker firm were also internal. The latter has no direct connection with the official
Third Reich-era German "V" designation, also signifying , for prototype aircraft, promulgated by the
RLM from 1935. The maritime aviation service used manufacturers' designations rather than the systematic system described above. For example, the landplane Gotha bombers were numbered in an "LD" (for "land biplane") series by their manufacturer, but in the "G" series in the – while the Gotha seaplanes used by the navy were (and continue to be) known by their manufacturer's "WD" (for , or "seaplane biplane") designation. Similarly, the sizable number of German seaplane designs from
Flugzeugbau Friedrichshafen, were all known in naval service by their "FF" factory designations. Army and navy airships were individually numbered, in the same way as contemporary German
destroyers and
submarines, and were outside any system of "type" designation. ==Pilots==