RLM aircraft designation system

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The RLM aircraft designation system was an attempt by the aviation bureaucracy of the Third Reich to standardize and produce an identifier for each aircraft type produced in Germany. It was in use from 1933 to 1945 though many pre-1933 aircraft were included and the system had changes over those years. A compiled list of the actual designations is here, the RLM-GL/C list. Mainly aircraft of the WW2 luftwaffe, but also civilian airliners and sport planes.

[edit] The System

When the RLM (Reichsluftfahrtministerium "Reich Aviation Ministry") was given control of the country's aviation activities in 1933, it set out to catalog aircraft already in production by various manufacturers as well as new projects approved for development by the ministry. The RLM thus made necessary improvements to a designation system which had been set up in 1929/30 by the Heereswaffenamt (Army Weapons Office) in the Reichswehrministerium (Defense Ministry), together with other institutions related to the industry. The former system had caused confusion in the use of aircraft designations among the different manufacturers. For example, no less than six aircraft of different firms had carried the number 33: these were the Caspar C 33, the Focke-Wulf A 33, the Heinkel HD 33, the Junkers W 33, the Klemm L 33 and the BFW M 33.

The improved designation system was introduced in order to provide a simple and unambiguous identification of every airplane. The heart of the new system was a (theoretically) unique number assigned by the RLM. In internal paperwork, this number was simply prefixed "8-" (or, in the case of sailplanes, subject to a separate numerical list, "108-"), while "9-" indicated aircraft engines. Also, the new standardized type designation added two letters representing the relevant firm's name. Dornier (Do) and Rohrbach (Ro) had already done this for some time. The first of these two letters had to be shown in upper case, the second always in lower case, despite its origin – thus, Fw for Focke-Wulf or Bf for Bayerische Flugzeugwerke. The very first exemption from this rule was granted several years later to Blohm & Voss when they renamed their aircraft manufacturing operation – which had been split off from Hamburger Flugzeugbau (Ha) – to Blohm & Voss and received the designation BV for their new aircraft, the first being the BV 138.

Thus, the RLM internally referred to a Messerschmitt twin-jet fighter project as type "8-262", although the same aircraft in service would be more generally known as the "Me 262". See List of RLM aircraft for a full list of designations allocated by the RLM and the aircraft to which they corresponded. Originally, these numbers were assigned sequentially and wherever possible attempted to take into account the manufacturers' own in-house design numbers for types already existing in 1933. Duplication resulted from the fact that when one manufacturer abandoned a project, the same number was occasionally re-allocated, with an appropriate time delay, to another manufacturer.

A list of the most common manufacturers and their letter designations is given below:

Al	Albatros	Fg	Flugtechnische Fertigungsgemeinschaft Prag	Ho	Reimar und Walter Horten
Ar	Arado	Fh	Flugzeugwerk Halle	Hs	Henschel
As	Argus Motoren	Fi	Fieseler	Ju	Junkers
Ba	Bachem	FK	Flugzeugbau Kiel	Kl	Klemm Flugzeugbau
Bf	Bayerische Flugzeugwerke (after July 1938, Messerschmitt AG)	Fl	Flettner	NR	Nagler-Rolz
Bü	Bücker	Fw	Focke-Wulf	So	Heinz Sombold
BV	Blohm + Voss	Go	Gothaer Waggonfabrik	Sk	Skoda-Kauba
DFS	Deutsche Forschungsanstalt für Segelflug	Ha	Hamburger Flugzeugbau	We	Weser Flugzeugbau
Do	Dornier	He	Heinkel	ZMe	Zeppelin/Messerschmitt
Fa	Focke-Achgelis	HM	Hirth Flugmotoren	ZSo	Zeppelin/SNCASO

Each individual prototype aircraft were suffixed with "V" (for Versuchs "prototype") and a unique identification number. So, for example, the Me 262 V3 was the third prototype of the Me 262 built. It should be noted, that V numbers were not used before February 1935.

Once accepted by Lufthansa or the Luftwaffe, major variants of the aircraft were suffixed alphabetically with a capital letter. For example, the major variants of the Me 262 were numbered Me 262 A, Me 262 B, and Me 262 C.

More minor variants were then suffixed numerically, beginning with -0 for pre-production evaluation versions. Thus, the first batch of Me 262 As supplied by Messerschmitt were designated Me 262 A-0, followed by production versions Me 262 A-1 through to (in the case of this particular aircraft) Me 262 A-5.

More minor variants still were given a lower case alphabetical suffix. When the Me 262 A-1a was to be experimentally equipped with different engines, in this given case the BMW 003 units, it became the Me 262 A-1b.

Finally, special conversions of basic types were given the suffix R/ or /U followed by a number. R means Rüststand and was usually done with aircraft taken from the assembly line. The Rüststand designation was used for modification of basic types in order to be usable for a specific mission task like recon, fighter-bomber or bomber-destroyer. U means Umrüstsatz (conversion kit) and was done with aircraft taken from the assembly line but also in repair workshops with airframes already in use. The Umrüstsatz designation was used for smaller equipment changes like additinal boost agents for the engine or a different main armament. For example, Me 262 A-1a/U3 referred to a small number of the standard Me 262 A-1a fighters that were modified by Messerschmitt as reconnaissance aircraft. The suffix trop (for "tropical") was applied to aircraft modified to operate in the hot and dusty North African and Mediterranean theatres, for example, the Bf 109 F-4 trop.

By the time the second world war started, manufactureres increasingly built developments of successful existing types rather than completely new designs. To reflect the 'lineage' of those aircraft, the new types were numbered in steps of 100 above the number of the basic model they were derived from. Thus, the Junkers Ju 88 formed the basis for the Ju 188, Ju 288, Ju 388, and Ju 488.

Another change in the system appeared halfway the war. With the Luftwaffes hunger for fresh airplanes far outpacing the capacity of the original manufacturers, certainly with its factories now regularly being bombed by the allies, aircraft construction was increasingly subcontracted and licensed out. As a result the name of the original manufacturer lost its significance: Its aircraft were now built by a variety of factories often without any links to the constructor whose name it bore. Therefore, the two-letter designation was changed to indicate the developer or design team rather than the (original) constructor.

Sometimes this update simplified matters. Messerschmitt for instance could now use the affix Me for its new designs rather than the former Bf for Bayrische Flugzeugwerke, after their transformation into Messerschmitt AG on 11 July 1938. The first aircraft to benefit from the change was the Me 210. Nevertheless the three aircraft Bf 108, 109 and 110 kept their Bf until the end. In other cases the new rules just created more confusion as for instance the successor of Focke-Wulf's Fw 190 was called Ta 152 after Focke Wulf's chief constructor Kurt Tank

For most manufacturers however, the designation remained the same: In smaller companies (like Klemm and Fieseler) the namesake owner and nominal chief designer were one and the same person while in bigger companies the planes were designed by a factory team with varying members.

A list of the most notable changes in designation appears below:

New designation	Designer (or design team)	old manufacturer	replaces designation
Ka	Albert Kalkert	Gothaer Waggonfabrik	Go
Hü	Dr. Ing. Ulrich Hütter	None (university professor)	He(*)
Li	Alexander Lippisch	DFS, Messerschmitt	(**)
Me	Messerschmitt	Bayerische Flugzeugwerke	Bf (after July 1938)
Si	Siebel	Flugzeugwerk Halle	Fh
Ta	Kurt Tank	Focke-Wulf	Fw
Wn	Wiener-Neustädter-Flugzeugwerke	the Messerschmitt factory near Vienna	(***)

BV	Blohm + Voss	Hamburger Flugzeugbau	Ha

(*) Although Hütter never worked for Heinkel, his only aircraft project, the Hü 211 was a development of the Heinkel 219 with a new high-ratio high-performance wing.

(**) No direct replacement

(***) Wn was used by WNF only for a few own designs like Wn 11, Wn 15 and Wn 16, of which no one reached a series production.

There is no single "master list" of designations that holds true throughout 1933-1945; the sequence is particularly muddled at the beginning and end of the list. To see the RLM-GL/C list in a numerical table, go to List of RLM aircraft
To see the RLM airplanes arranged by manufacturer, go to RLM aircraft by manufacturer