Leichtflugzeugbau Klemm Aircraft Designations
As noted above, Klemm type designations originating with the Daimler-Motorenwerke-Gesellschaft aircraft designation series. DGM's 'L' designation sequence would be continued by the Leichtflugzeugbau Klemm GmbH until long after the RLM applied its 'Kl' company designation in 1933. After that, a new 'Kl 10x' sequence was begun. However, the 'Kl' prefix was also allied as a backformation to old DGM-style type numbers - eg: the L 25 becoming Kl 25 or the 'L 31' emerging as the Kl 31.
The RLM system later imposed its own numbering sequence running from the 1937 Kl 104 to the wartime Kl 107. [2] When aircraft production was allowed to resume in postwar West Germany, Klemm teamed with Ludwig Bölkow to restart production of KL 107 series lightplanes. Here, the Nazi-era lower-case 'l' was replaced with a capital letter but the RLM numbered was retained. This would be the last aircraft type produced under the Klemm name but its numbering would influence Bölkow 's KL 107 derivative - the Bö 207.
A Leichtflugzeugbau Klemm Designation Anomaly
One anomaly is the Klemm
Alpha motorglider - an ultralight glider fitted with a '
hilfmotor'. In his list,
hesham has suggested that the
Alpha may have been designation L 29. At first glance, that seems to make sense - especially considering the close structural relationship between the
Alpha and the L 30 2-seat light aircraft. Unfortunately, there is no evidence. Contemporary Klemm documents discuss the commonality of the
Alpha and the L 30 without any mention of an 'L 29'. So, I will list the anomalous
Alpha here:
Klemm
Alpha - 1931 experimental motorglider; 1 x prototype
-- Anomalous naming with no know 'L' (or other) numbered desig.
-
Alpha: Prototype D-2217 (WNr. 261); insufficient glide rate
-
Alpha: 1 x 20 hp Daimler F7502 aux. engine; span 14.00 m
-
Alpha: Devel. ended 1932; used as teaching aid by Klemm*
-- * Destroyed by Allied bombing at Böblingen in Oct. 1943
--
https://www.secretprojects.co.uk/threads/klemm-alpha.33477/
Since
hesham has gone out on a speculative limb, I will follow his example. Here, with no evidence whatsoever, I am going to posit
possible explanations for the
Alpha naming anomaly. To wit, circa 1930, the Leichtflugzeugbau Klemm may have toyed with dropping the 'L' designation sesquence inherited from Daimler. In this speculative notion, the
Alpha may have been seen as the first of a new generation which was later aborted.
But, in Klemm documents, that
Alpha naming and the L 30 designation coincide. Taking that into account, a more probable theory is that Klemm considered dropping designations for names for gliders alone. That might explain why a named motorglider and a designated light trainer were being developed concurrently. But, of course, that motorglider was a flop and, thus, there never was a Klemm '
Beta'.
All speculation aside, what we do know is that there is no evidence that the designation 'L 29' was ever applied.
A Note on Style
Early Leichtflugzeugbau Klemm designations are presented in a range of ways. In contemporary German sources, the are most often present with a space between the 'L' and type number. I have chosen to standardise on this form (despite modern German usage commonly omitting that space). Contemporary English language sources tended to insert a period or hyphen between the 'L' and type number.
Leichtflugzeugbau Klemm sub-type variant suffix styles vary over time. Initially, lower-case letters were applied (although the aviation press often capitalised these anyway). Other times, sub-type variants with more major changes were indicated with Roman numerals (sometimes followed by lower-case letters). Those Roman numerals get confusing because competition
klasse designators were also regularly appended to Klemm designations - again in Roman numerals.
There were exceptions to the capitalisation rule - eg: the L 25E (for
Europa Rundflug) - but these were more marketing department exercises. In the example given, the actual Klemm designation was L 25 Ve (
qv) but 'E' for
Europa just looked better on the brochures. Another capital was the 'W' for
Wasser that was typically applied to floatplanes. These too varied. A generic designation was L 25 W for any L 25 airframe fitted with floats while the designation L 25 IW referred specifically to an L 25 I-model floatplane.
When the Nazi-era RLM imposed its designation style upon German manufacturers, sub-type suffixes officially became capitalised. Even still, 'Kl' for 'L' backformation designations will often be seen retaining their original, lower-case sub-type suffixes. After 1934,
Versuch nummern are also seen being appended to Klemm prototype designations.
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Leichtflugzeugbau Klemm 'L' and 'Kl' Designations
L 23 - (??)
no details; type number presumed reserved [1]
- L 23: Wiki.de suggests being held for experimental aircraft
L 24 - (??)
no details; type number presumed reserved
- L 24: Wiki.de suggests being held for experimental aircraft
L 25 - 1927 2-seat low-wing light sports monoplane; x ~660
- L 25a : 1927-29 production model; various 20-60 hp engines
-- L 25a : Base model; 1 x 20 hp Daimler F5702; span 13.00 m
-- L 25a VI: (Planned) 1 x 40-50 hp BMW X 5-cyl. radial engine
-- L 25a VI: 1 x 50-60 hp BMW Xa 5-cyl.; eg: D-EMBX W.Nr. 149
- L 25 I: 1928-29 prod'n model; 1 x 45 ps Salmson AD.9 radial
-- L 25 Ia: 1 x 40 ps Salmson AD.9 9-cyl. radial; span 13.00 m
-- L 25 Ia: aka 'L.25a-1' (eg: April 1929, April 1930
Flight, etc.)
-- L 25 IW: (
Wasser) Twin-float seaplane version of L 25 Ia
- L 25b: 1931 prod'n variant; various engine types installed
-- L 25b : 1931; 1 x 22 hp Daimler (Mercedes) F5702a HO2
-- L 25b I: 1 x 40 hp Salmson 9Ad 9-cylinder radial engine
-- L 25b IV: 1932 Armstrong-Siddeley
Genet 5-cylinder radial
-- L 25b VI: 1 x 40-50 hp BMW X 5-cylinder radial engine
-- L 25b VII: 1 x 60-65 hp Hirth HM 60 inverted 4-cylinder engine
-- L 25bf VII: Had reduced wingspan and a modified fuselage
-- L 25b VIIR: 1 x 80 hp Hirth HM 60R inverted 4-cylinder engine
-- L 25bf VIIR: Had reduced wingspan and a modified fuselage
-- L 25b XI: 1 x 85 hp Pobjoy R 7-cylinder air-cooled radial
-- L 25c VII: 1933
-- L 25d II : 1933; 1 x 85 hp Siemens-Halske Sh 13a radial
-- L 25d VII: 1 x 60-65 hp Hirth HM 60 4-cylinder
-- L 25d VIIR: 1934; 1 x 80 hp Hirth HM 60R 4-cyl.
-- L 25e VII : (??) no details but not the same as the L 25E
-- L 25E : (
Europa Rundflug); same as the L 25 Ve (
qv)
-- L 25 IVa: 1 x 80 hp Armstrong Siddeley
Genet 5-cylinder
-- L 25 Va: 3-seater; canopy; 1 x 105 hp Argus As 8 4-cylinder
-- L 25 Ve: 1930 for Europa Rundflug; canopy; shorter wings
-- L 25 Ve: aka L 25E; 1 x 105 hp Argus As 8 4-cylinder inline
-- L 25 W: Salmson 9Ad-powered twin-float seaplane conv.*
-- * As per listing in Jan 1932
Flight magazine
-- No desig. change known for L 25 testing 'personnel pods'
-- British Klemm/British Aircraft
Swallow desig. omitted
-- US Aeromarine built L 25 variant designations also omitted
--
https://www.secretprojects.co.uk/threads/aeromarine-projects-and-prototypes.18424/page-3#post-266549
-- Horace Keane Aircraft 1937 Ford V8-powered L 25 omitted
L 26 - 1929 2-seat low-wing light sports monoplane; x ~170
- L 26 : Reinforced derivative of the L 25 sports/ trainer
- L 26a : 1 x Argus As 8 A-2 4-cyl.; eg Liesel Bach's D-1916
- L 26 II : More powerful; Siemens-Halske Sh 13 radials
-- L 26 IIa : Siemens-Halske Sh 13; eg: D-1801 (WNr. 185)
-- L 26 IIc : Siemens-Halske Sh 13a; eg: D-2412 (WNr. 495)
- L 26 III: 2-seat tourer; fitted with a canopy
- L 26 V : 2-seat trainer/tourer; most produced variant
-- L 26 Va : 1 x 95 hp Argus As 8A-2 inline 4-cylinder
-- L 26 Vc : 1 x 120 hp Argus As 8A-3 inline 4-cylinder
-- L 26 Ve : 1 x 120 hp Argus As 8A-3 inline 4-cylinder
- VL 26 : 3-seat touring aircraft variant
L 27 - 1929 light transport/sports evol. of Klemm VL 26; x 8
- L 27 : Strengthened & lengthened VL 26 fuselage for cargo
- L 27 : Reinf. fwd cockpit bay for freight, mail, newspapers
- L 27 V1: First prototype was probably D-1744 (WNr. 190)
- L 27 V1: 1 x 100 hp Argus As 8 inverted 4-cyl.; span 13.20 m
- FL 27 : 1930 light cargo a/c offering; but no known sales*
-- * Minimal payload; few advantages over L 26s with Argus
- L 27 : FL 27s sold as aerobatics or to German aero-clubs; x 3
- L 27 IIB: 1931 British Klemm conv. to 105 hp Cirrus
Hermes IIB
- L 27 III: 1930 British Klemm conv. to 95 hp Cirrus Mark III
- L 27 III: 1931 British Klemm conv. to 107 hp DH
Gipsy III
L 28 - 1933 single-seat light aerobatic a/c monoplane; x 1
- L 28 : For Liesel Bach; not accepted until improved, 1934
- L 28 : 1 x 150 hp Siemens Sh 14a 7-cyl.; span 11.00 m
- L 28 : Mixed constr. with wood-clad steel-tube fuselage
- L 28 : aka L 28 XIV (ie:
klasse XIV competition a/c)
-- Bach's D-2495 (WNr. 447) won 1934
Coupe Féminine
-- NB: Bach requested that number 28 be reserved for her*
-- * Robert Lusser aerobatic design work prob. since 1919
L 29 - (??)
no information
- L 29 :
hesham suggests
Alpha was L 29; no evidence
L 30 - (Project) 2-seat light training a/c related to
Alpha
- L 30: Closely-related structurally to single-seat
Alpha*
-- * Wooden wings; steel tube fuselage frame and tailplane
- L 30 : (As planned) 1 x (??) hp Klemm-Aero KA 2-stroke**
-- ** Unrealised Karl Schopper design; devel. cancelled 1936
- L 30: 1 x 46 hp Church
Marathon J-3; [2] span 11.50 m
- L 30: (Alt) 1 x 40 hp Argus As 16 HO4 engine; span 11.50 m
- L 30: A 'cutaway' mockup of L 30 built showing Argus As 16
L 31 (Kl 31) - 1931 3-seat competition cabin monoplane; x 36
- Kl 31 : Tourer; wood wings, welded steel-tube fuselage
- Kl 32 : First prototype; WNr. 357; tested winter 1931/32
-- Kl 31 XIV =
XIV Sportflugzeug for 1932
Europa Rundflug
- Kl 31 : 1 x 120 hp Argus As 8 inline 4-cyl.; span 13.50 m
-- Kl 31 had stuctural problems; briefly eclipsed by L 32
- Kl 31a: 1 x 160 hp Bramo Sh 14a/A4; span 13.50 m; x 4
- Kl 31a XIV: Sept 1933 series production vers. of Kl 31a
- Kl 31ab : 1934; improved control aids & aerodynamics*
-- * Kl 31ab featured an aerodynamic NACA canopy; x 1
-- * Kl 31ab also featured extensible slats & landing flaps
L 32 - 1931 low-wing cantilever monoplane light a/c; x 36
- L 32 : Robert Lusser design; lighter, reduced-scale Kl 31
- L 32 : L 31 cabin structure applied to wooden L 25 constr.
- L 32 : Wing flaps; 150 hp Siemens Sh 14; span 13.50 m
-- L 32 demonstrator Wnr. 402 became G-ACYU, July 1932
- L 32a : Wing landing flaps omitted; range of engines*
-- * Sh 14a; Argus As 8; DH
Gipsy; & Hirth HM 150 4-cyl.
- Kl 32b: Slightly modified fuselage; more powerful radial
-- Kl 32b D-ENIF fitted with extra tanks for Elly Beinhold
- Kl 32b XIV: 1 x 160 hp Siemens Sh 14a; span 13.50 m
- L 32V: VH-UVE (orig. D-2299); Maude Bonney record flight
-- 1937; first Brisbane to Cape Town, SA, flight; 29,088 km
L 33 - 1932 '
Volksflugzeug' single-seat ultralight a/c; x 1
- L 33 : Parasol;* very conventional appearance; no brakes
-- * Really a shoulder-wing; slight gap btw wing & fuselage
- L 33 : (As planned) 1 x (??) hp Klemm-Aero KA 2-stroke**
-- ** Karl Schopper design for L 30; devel. cancelled 1936
- L 33 : (As built) 1 x 18 hp DKW P 2-stroke; span 11.00 m
-- DKW P was an inline 2-cylinder adapted from auto use
- L 33 : aka Kl 33; WNr. 374(?); 1938 registration D-EYDO
E 34 - 1932 experimental 2-seat biplane trainer; x 1
- E 34 : Mixed constr.; wood with steel-tube fuselage
- E 34 : 1 x 150 hp Siemens Sh 14A 5-cyl.; span (??) m
Kl 35 - 1935 2-seat light sports/military trainer; x 1,429
- Kl 35 : L 25 devel.; wood-covered steel-tube fuselage
- Kl 35 V1: Feb 1935 1st prototype; D-EHXE (Wnr. 959)
- Kl 35 V1: E-Stelle Rechlin, 01 June; crashed 19 June*
-- * Fatal crash for 2 x E-Stelle personnel; wing failure
- Kl 35 V2: 2nd prototype; D-ERQA (Wnr. 960); Rechlin
- Kl 35A : Klemm (LFK)-built 1st production model; x 57
- Kl 35A : 1 x 80 hp Hirth HM 60R 4-cyl.; span 10.40 m
- Kl 35AW: (
Wasser) 1937 twin-float conv. of Wnr.1183
- Kl 35B : Fieseler-built production model; x 142
- Kl 35B : 1 x 105 hp Hirth HM 504 4-cyl.; span 10.40 m
- Kl 35C : Kl 35 airframe adapted to semi-shell constr'n
-- Kl 35C V1: 1937 first prototype; D-EAED (Wnr. 1240)
-- Kl 35C V1: 1 x 65 hp Hirth HM 60 4-cyl.; span 11.20 m
-- Kl 35C V2: 1937 2nd prototype; D-EOKX (Wnr. 1241)
-- Kl 35C V3: 1939 3rd prototype; D-EBCQ (Wnr. 1480)
-- Kl 35C V3: Intended as production Kl 35C prototype*
-- * Proved overweight; Kl 35C prod'n cancelled by RLM
-- * Devel. privately as the non-semi-shell Kl 106 (
qv)
- Kl 35D : Revised Zlín prod'n model; tailwheel (not skid)
- Kl 35D : 1 x 105 hp Hirth HM 504A-2 4-cyl.; span 10.40 m
- Kl 35D : 39 x built (vs 332 planned); Bü 181 was superior
- Kl 35E : 1940 prototype; re-engined Kl 35B airframe; x 1
- Kl 35E : 1 x 105 hp Hirth HM 500A-1 4-cyl.; span 10.20 m
- Kl 35E : RLM ordered x 102; Nov 1940, then cancelled **
-- ** Travemünde tested D-EGJK; eclipsed by the Bü 181
- KL 35-D160: 1960s Wolf Hirth GmbH, Nabern, conv. ; x 2
- KL 35-D160: 1 x 160 hp Walter
Minor; span 10.20 m
- KL 35-D160: aka KL 35
Special; Wnr. 2013 still flying
-- No designations are known for wartime exper. mods ***
-- *** DFS 230 '
Mistel'; '
Zwilling'; or DVL mods
Kl 36 - 1934 single-engined 4-seat cabin monoplane tourer; x 12
- Kl 36 : F. Fecher design specifically for 1934 Europa Rundflug
- Kl 36 : 1 x 225-to-250 hp inline (various types);* span 12.00 m
- Kl 36 V1: 1 x 225 hp Argus As 17 inverted 6-cyl.; span 12.00 m
- Kl 36A XVII: Comp. a/c; 1 x Argus As 17a; D-IJIP (WNr. 656)
- Kl 36A XII : Comp. a/c; 1 x Hirth HM8U; D-IHEK (WNr. 657)
- Kl 36A XVII: D-IDIR (WNr. 658); D-IBAV (' 659); D-IAGO ' 660)*
-- * D-IAGO built as reserve a/c; became the pre-series Kl 36B-01
- Kl 36B : 1935 pre-production; WNr. 660 repl. by D-IKYM WNr. 720
- Kl 36B : 160 hp Siemens-Halske Sh 14A-1 or Hirth HM 508 ; x 7**
-- ** Oct 1935, RLM ordered 50 x Kl 36B; order cancelled March 1936
-- ** All 7 x Kl 36B later transferred to the DVL for research uses
-- Kl 36B/Kl 36 V7 (D-IUHU) fitted with outward retracting main u/c
E 37 - (Project) 1935 4-seat cabin tourer; low-wing monoplane
- E 37 : 2 x 250 hp Hirth HM 8U air-cooled IV-8; span (??) m
- E 37 : Concept realised in 1937 Klemm Kl 104/Fh 104
Hallore
-- NB: Zöller lists as "Kl 37 (E.37)" suggesting advanced stage
E 63 - (Project) 1934 2-seat carrier-borne parasol recce monoplane
- E 63 : Braced parasol; spatted main u/c; open or closed cockpit
- E 63 : 1 x Junkers or BMW inverted V12 engine;* span 14.00 m
-- * 680 hp Junkers
Jumo 210A or 700 hp BMW XII/BMW 116
- E 63 : All work on E 63 & E 64 projects cancelled in Jan. 1935
--
https://www.secretprojects.co.uk/threads/klemm-e-63-64.2189/#post-18559
E 64 - (Project) 1934 2-seat carrier-borne reconaissance biplane
- E 64 : Single bay wings; spatted main u/c; open or closed cockpit
- E 64 : 1 x Junkers or BMW inverted V12 engine;* span 12.00 m
-- * 680 hp Junkers
Jumo 210A or 700 hp BMW XII/BMW 116
- E 64 : All work on E 64 & E 63 projects cancelled in Jan. 1935
--
https://www.secretprojects.co.uk/threads/klemm-e-63-64.2189/#post-18560
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[1] Note: OCR often misinterprets numerals from blackletter fonts used in pre-WW2 German newspapers and other publications. Eg: Page 3, 28 July 1930,
Beiblatt der Danziger Volhsstimme where OCR presents 'Klemm L. 23 e' [
sic] which is clearly readable as "Klemm L. 25 e" in the original text.
[2] The
Marathon J-3 was a inline 4-cylinder from the Chicago-based Church Airplane Company. Derived from the Heath-Henderson B-4 motorcycle engine,
Marathon J-3 displacement was increased to 108 cid (1.77 litres). Argus Motoren Gesellschaft negotiated unsuccessfully with Church to secure a license for German production of the
Marathon J-3.
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