It’s taken a while but the Entwicklungsprogramm referred to by Lennart has now been run to ground. It’s in BA-MA archive file reference RL 3 1448 with Flugzeugentwicklungsprogramm, 1. Oktober 1936.
The entries in this file on Blätter 15 & 16 confirm that the three-seater Bf 108 B-0 Nullserie were designated as Versuchsmaschinen V1 to V7 and assigned W.Nr. 871 to 877, with three different types of engine required to be fitted. However, the V-Nummern are not assigned sequentially.
· (Programm Row 219) The Bf 108 B-0 V1 and V2 were W.Nr. 871 & 873 respectively: these were to be fitted with the 250 hp Hirth HM 8U.
· (Row 220) The V3 to V6 were: W.Nr. 872 & 874 to 876; all to be fitted with the 160 hp Siemen Sh 14a.
· (Row 221) The V7 was W.Nr. 877 and the sole example to be fitted with the 240 hp Argus As 10 III.
Thus, exactly as pointed out by Lennart, the Bf 108 B Versuchsmaschinen are nestled between the Werk-Nummern for the Bf 110 V1 to V3 and the Bf 109 V4 to V9, and are numbered after the first Bf 108 B production block. (We already know that Mtt back-filled some of the gaps left in their Manufacturer's W.Nr. sequence from the W.Nrn. that were assigned to the Me 209. Those seem to have been first allocated as the final four of a block of 50 assigned to the cancelled order for 50 x Ju 87s from BFW.)
According to this programme the first six Bf 108 B-0 had been completed in Nov-35, but for the Argus-engined V7 this did not happen until Aug-36.
The comparison with the competing four-seater Klemm Kl 36 B is instructive:
· (Row 222) Kl 36 B V1 to V4 (W.Nr. 1016/7, 1019 & 1031) with the 250 hp Hirth HM 8U.
· (Row 223) Kl 36 B V5 to V7 (W.Nr. 1014/5 & 1018) with the 160 hp Siemen Sh 14a.
No mention of an Argus-powered Kl 36 B. (Perhaps it was simply not feasible to fit an As 10 into a Kl 36 B?)
So the gentlemen of the RLM were not trying to make Messerschmitt’s life any more difficult than anyone else’s, although that was what I had first thought. They simply wanted to test out in the most practical fashion the engine options in both competing types.
In this competition the Bf 108 started with the handicap that it was a three-seater whereas the Kl 36 was a four-seater. However, the decisive advantage that the Bf 108 had over the Kl 36 was probably not its lightweight all-metal monocoque construction, but rather that the Bf 108 could be fitted with and perform most satisfactorily with one of the great standard engines selected by the RLM for the Luftwaffe (and also fitted through more than a decade in the Ar 66, Go 145, Fw 58, Ar 76, Fw 56 & Fi 156). Thus the Flugzeugentwicklungsprogramm, 1. Oktober 1936 already notes against the rows for the Bf 108 V1 to V6 “Werden auf As 10 C III umgenbaut nach d.Entwicklungsmuster lfd.Nr, 221 W.-Nr. 877,
and against the rows for the Kl 36 B “Serie wird nicht beschafft.”.
So the initial reconstruction I posted of the early blocks for Bf 108 W.Nrn. that read:
38 x Bf 108 B-1 (W.Nr. 830 to 867, delivered 1935/7)
7 x Bf 108 B-1 (W.Nr. 871 to 877, delivered 1937).
6 x Bf 108 B-1 (W.Nr. 987 to 992, delivered 1937)
now becomes:
43 x Bf 108 B-1 (W.Nr. 823 to 865, delivered 1936/7)
7 x Bf 108 B-0 (Bf 109 V1 to V7, W.Nr. 871 to 877, delivered 1935/6)
2 x Bf 108 B-1 (W.Nr. 908 & 909, delivered 1937, both identities known)
6 x Bf 108 B-1 (W.Nr. 987 to 992, delivered 1936/7) – This last looks like an initial batch made up exclusively of privat (commercial) sales. Certainly the first example went to Brazil and the last to Australia.
Thus the final iteration of 45 Bf 109 B-Serie for the first order as built, comprised W.Nr. 823 to 865 (43) & W.Nr. 908 to 909 (2). The initial placement of this order for 37 aircraft was presumably assigned W.Nr. 823 to 859.
The above addresses Lennart’s boxes 1, 4 & 5.
Regarding box 6, most likely J-BACC was the first singleton example bought for assessment by Manchuria and was also from this 987 to 992 batch. I would love to see the source reference for this sighting, however, in my judgement it will not have been for W.Nr. 993.
The reason is that W.Nr. block 993 to 997 was assigned to the 5 x Bf 109 A Null-Serie of the third batch. [Radinger & Schick: Me 109 A/E table p.34 where they are simply described as A-Serie]. A duplicate assignment of just this specific W.Nr. would not be impossible in principle – Manchuria is after all a long way from Germany. But J-BACC was apparently registered in Aug-36, and for this assignment to be made so close in time to the other imj wholly rules this out – subject, of course, to seeing incontrovertible evidence of this duplicate assignment. (Smiley face)
On two others of Lennart’s other points I can now also respond.
Box 7: Lennart is correct. 11-July 1938 marked the change of company name at Mtt-Augsburg. In Ebert’s Willy Messerschmitt, Schiffer edition p.194 is a photograph of a share certificate endorsed with the name change on this date.
Box 10: Yes, HB-EKO subsequently became Swiss Air Force serial A-208, but it was delivered as HB-EKO and photographed prior to delivery as HB-EKO by Messerschmitt’s production test pilot at Regensburg. Go look at the photo in Schmoll that I mentioned originally, or in the English version at Schmoll’s Nest of Eagles p.17.
Ironically, the shot in Schmoll is taken from an angle that leaves the top of the last letter hidden. It could in fact be either a U or an O. However, Schmoll had access to Trenkle’s logbook and this is indisputably a 1939 delivery from Regensburg, whilst W.Nr. 1129 was indisputably a 1937 delivery from Augsburg. Indeed W.Nr. 1129, delivered Dec-37, was the example flown by Otto Brindlinger on a tour across the Americas, starting in Rio de Janiero and ending in New York. [Tincopa+Rivas: Axis Aircraft in Latin America, table p.355] From Stig’s post it then seems to have ended up in Switzerland, presumably sold as slightly used. Thank you for that pointer, Stig.)
[The detailed register entry for HB-EKU, W.Nr. 1129, in Golden Years at
http://www.airhistory.org.uk/gy/reg_HB-.html
confirms what Stig wrote, identifying W.Nr. 1129 as “HB-EKU A-216(HB) HB-HOM A-216(HB)” first registered on 25.05.39 to Max Fiedler /Zurich.
There is no listing in Golden Years for HB-EKO.
Agreed, HB-EKU has nothing to do with HB-EKO, W.Nr. 2064 apart from them both ending up in Switzerland.]
The Swiss impressed at least one civil example of the Bf 108 and along with those purchased for the air force, all of the HB-xxx civil registrations were replaced by serial numbers in the range A-2xx starting at A-201. It would be good to have an input from a specialist on the Swiss Air Force as to exactly when these changes happened. Were the HB- codes for the 1939 deliveries from Regensburg production only used as delivery codes? Or were the A-2xx assignments only made subsequently during wartime when the aircraft were camouflaged? (The second is my working hypothesis for the present.)
Lennart, thank you for your always valuable contributions. I will go dust up and recheck my sources for the D-Kennz. assignments to early Bf 108s.