RLM aircraft designation system

The German Air Ministry - the Reichsluftfahrtministerium (RLM) - had a system for aircraft designation which 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.
As well as aircraft of the Luftwaffe, it covered civilian airliners and sport planes.
== The system ==
When the Reichsluftfahrtministerium was given control of the country's aviation activities in 1933, it set out to catalog both the aircraft already in production by various German manufacturers as well as new projects approved for development by the ministry. The RLM 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; six aircraft of different firms used the number 33.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. The new standardized type designation added two letters representing the manufacturer; Dornier (Do) and Rohrbach (Ro) already used this practice. The first of these two letters was shown in upper case, the second always in lower case, no matter its origin – so 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 of which was the BV 138. 
As such the RLM referred to a Messerschmitt twin-jet fighter project internally as type "8-262", although the same aircraft in service would be more generally known as the "Me 262". 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. 
letter designations for major manufacturers 
Al 	Albatros 	Fg	Flugtechnische Fertigungsgemeinschaft Prag	Ho 	Reimar und Walter Horten
Ar 	Arado 	Fh	Flugzeugwerk Halle, later Si for Siebel 	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
==Prototypes and variants==
After February 1935, each individual prototype aircraft were suffixed with "V" (for Versuchs German: "prototype") and a unique identification number. So, for example, the Me 262 V3 was the third prototype of the Me 262 built. 
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 was an abbreviation of Rüstsatz, a pre-packaged kit of parts that was usually installed on aircraft in the field. The Rüstsatz 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 was Umrüst-Bausatz ("conversion kit"), often contracted to Umbau, and was done with aircraft taken from the assembly line but also in repair workshops with airframes already in use. The Umrüst-Bausatz designation was used for smaller equipment changes like additional 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.
==Name changes and new constructors==
In 1933 Germany's largest shipbuilder Blohm & Voss in Hamburg opened an aircraft subsidiary under the name of Hamburger Flugzeugbau. RLM awarded this factory the designation Ha. However the connection with 'Hamburgs tradition' Blohm & Voss was just too strong to be neglected and the aircraft coming from the Hamburger Flugzeugwerke were commonly known as 'Blom & Voss type Ha xxx' . Finally the RLM caved in to popular views and gave the factory a new designation BV for Blom & Voss.
Bayerische Flugzeugwerke ("Bavarian Aircraft Works") was founded in 1926 out of the bankrupt remainder of former Udet flugzeugbau. Originally producing its legacy of Udet-designed sportsplanes, it later went on to secure the services of Willy Messerschmitt, not as a chief engineer but as a free-lance designer. Thus BFW in Munich and Augsburg would produce and distribute designs from Flugzeugbau Messerschmitt in Bamberg. For some reason, (and also in part because of a deep personal animosity between Willy Messerschmitt and State Secretary of Aviation Erhard Milch) the RLM awarded the manufacturers designation NOT to Messerschmitt but to BFW and thus Messerschmitt's record sportsplane design M 37 was produced as the Bayerische Flugzeugwerke Bf 108. Dissatisfied with this settlement, Messerschmitt himself used the money from the sales of his designs to buy a tract of land in Regensburg, founded the Messerschmitt GmbH aircraft factory and planned (or threatened) to start aircraft production on his own. Forced to choose between giving Messerschmitt his due and becoming a pure subcontractor, on 11 July 1938 the Bayerische Flugzeugwerke took on Messerschmitt as chairman and managing director, took over the Regensburg plant and renamed itself the Messerschmitt AG. The RLM assigned this 'new' factory the designation Me. The first aircraft to benefit from the change was the Me 210. Nevertheless the three aircraft Bf 108, 109 and 110 officially kept their Bf prefix, due to their pre-July 1938 origins, until the end. 
In 1933, the RLM found that its aircraft production was concentrated too much in the South and West of the country and therefore asked Hanns Klemm to relocate his factory Klemm Flugzeugbau from Böblingen in Bavaria to the town of Halle in Saxony. Unwilling to leave his 'home turf,' Klemm teamed up with financier Fritz Siebel and founded Flugzeugbau Halle: a completely new factory in Halle license-building Klemm designs under the RLM designation Fh. However by the time the first Halle design, the Fh 104 (that started its life on the drawing board still as the Klemm Kl 104) had flown in 1937, Siebel became majority shareholder of the new factory, bought in his own design team and renamed the factory Siebel Flugzeugwerke KG, henceforth producing his own designs under the RLM letter designation Si.
Also in 1933, the glider schools of the Rhön-Rossitten Gesellschaft were incorporated into the Hitlerjugend, while its construction and research team continued as a pure experimental think tank under the name Deutsche Forschungsanstalt für Segelflug or simply DFS. Although the DFS was a pure research facility and lacked the means of series production, several of its designs were license-built by various aircraft factories. Uncharacteristic for the RLM, these designs retained the 3-letter all-capital designation DFS.
A list of the most notable changes in designation appears below:
New designation	Official name	Former name 	replaced designation
BV 	Blohm + Voss 	Hamburger Flugzeugbau| 	Ha
Me 	Messerschmitt	 	Bf (after July 1938)
Si 	Siebel 	Flugzeugwerk Halle 	Fh
DFS 	DFS 	(Rhön-Rossitten Gesellschaft)	
==Evolution of the designation system==
By the time the Second World War started, manufacturers 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 was the gradual replacement of the two-letter prefix for the constructor with a prefix for the designer. Almost from the beginning the RLM used an elaborate system of licence-building and subcontracting to maximize its output of huge numbers of relatively few types of 'standard equipment' airplanes. Initially, the factory that designed the plane maintained the biggest share of that planes production. With the war proceeding, the Luftwaffe's need for fresh airplanes quickly outpaced the capacity of the original manufacturers, certainly with its factories now regularly being bombed by the Allies. As a result the connection between aircraft and original manufacturer eventually lost its significance. Aircraft were now built by a variety of factories often without any links to the constructor whose name it bore. Furthermore, aircraft engineers and designers, a hot commodity for a constructor and therefore aggressively courted and headhunted, were famous for their tendency to leave one company for the next bigger one every few years. Finally more and more of them started their own aircraft development company under their own name. The RLM followed suit by giving their products a two-letter designation reflecting the constructor's name rather than the constructor he (originally) worked for. To further complicate things, those new design bureaus were often assigned ranges of aircraft numbers formerly assigned to other constructors but unused. Thus when Focke-Wulf's chief constructor Kurt Tank founded his own design bureau he got assigned the prefix Ta and the numbers 151 through 154. As a result, the further development of his Focke-Wulf Fw 190 became the Tank Ta 152 but remained commonly known as the Focke-Wulf Ta 152.
New designation	Designer(or design team)	Former manufacturer 	replaced designation
Ka 	Albert Kalkert 	Gothaer Waggonfabrik 	Go
Hü 	Dr. Ing. Ulrich Hütter 	None (university professor)	He (*)
Li 	Alexander Lippisch 	DFS, Messerschmitt 	DFS / Me
Ta 	Kurt Tank 	Focke-Wulf 	Fw
(*) 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.
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. 
(For see the RLM airplanes arranged by manufactuer, see RLM aircraft by manufacturer)
==Related content==
*List of RLM paint designations
*List of aircraft engines of Germany during World War II
*List of weapons of military aircraft of Germany during World War II
*RLM numbering system for gliders and sailplanes
*RLM aircraft by manufacturer
==See also==
* Common WW2 Weapons
* List of aircraft of the Armée de l'Air
* List of Sailplanes
==Notes==
==References==
==External links==
*Virtual Aviation Museum
*German Military Aircraft Designations (1933-1945)
Category:World War II German aircraft
Category:Nazi Germany
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