Messerschmitt Bf 109G-10/U4
Production & Operational Service

Cover previewThe second part of special serie “Luftwaffe over Czech territory 1945”. One of the main producers of Messerschmitt 109, Wiener Neustädter Flugzeugwerke and its branch plant Diana located in railway tunnels near Tišnov produced and delivered the famous fighter Bf 109 in G-10/U4 variant nearly until last days of WWII. The new title describes mentioned variant from technical point of view, it brings information about production system in Diana plant, about test flights in Protektorat area and about service by combat units including actions over Czech and Slovak territory. The text part is accompanied by photos and by color profiles of planes from ex-II./JG 51, II./JG 52, ex-I./JG 53, Hungarian 101.vadaszezred and Jagdstaffel ROA, 6 of them are described in detailed 4view drawings.

Discussion forumMesserschmitt Bf 109G-10/U4 Production & Operational Service

12. 3. 2006, 23:43
late 109s
from: Andreas Beck
1.After having worked through the two latest works on the 109s (Deutsch Brod and the WNF G-10s)the desire for a comprehensive monography on late 109s is awakened. The first try by John Beaman dates back to the mid seventies, then state of the art . My congrats and respect for both , editorial and research work acomplished with these two JaPo books.
2.In my view the stated thesis of a new lower engine cowling omitting the "chin bulges" done by Erla has found now real proof of photographic evidence. Years back J.C. Mermet published an article in "Luftwaffeverband" about this saying that a new broader lower cowl was designed. This must have been extremely broader than the ones used in all other versions , same for the oil cooler. Or another solution might have been a different layout on the oil tubes which caused the bulges.
3.Did DB 605 A/AS/ASM engines also fit to the new designed engine bearers of the G-10 and K series and if, is there any evidence that this happened ?
4.Can it be that the cws plug in the upper position was also installed in DB 605 AS/ASM powered airframes. The electrical system of an aircraft is a component of its own and so it might have been combined with these versions, too (Regensburg airframes).
Andreas Beck, Berlin
7. 4. 2006, 14:56
Re: late 109s
from: Tomáš Poruba   to: Andreas Beck
Dear Andreas,

I´m sending you my answer to your questions about Bf 109. I´ll answer step by step.

1) You are right, that bottom engine cowling of Bf 109G-10s (and probably G-14/ASs) from Erla factory were wider and lower. It was a part of different engine cowling made for DB 605D in the factory. No changes on own engine or pipe leadings of DB 605D were here and differences were only in the cowling.

I´m not sure, why the different cowling of the engine was made in Erla, but maybe it cohereted with effort to make aerodynamical "cleaner" cowling for Bf 109G/K used engine DB 605D. The development still ran in 1944.

A result of the situation was two existing cowlings of the engine - one was made by Mtt Regensburg and it was used on K-4, G-10 (and some G-14/AS) from the producer and in addition on G-10/U4 from WNF. The cowling was based on previous one (for DB 605A engine) and some parts were only modified (the botom cover by the two bulges) and some of them were made new (top covers of engine). The cover was easier to start product.

The second solution was made by Erla and the cowling was absolutely new. It was aerodynamicaly better, but its production was more difficult.

Both solutions were accepted by producers and it is visible from Ersatzteil-liste of Bf 109K. There are mentioned both - in "Triebwerk" (it means all engine group, e.i. Engine, all equipments catched on engine, bearers and all cowling) case are mentioned "109F 620" or "109F 623".

The 109F 620 was the solution from Mtt Regensburg, the 109F 623 was the Erla one. Not only "Triebwerk had to by changed, so there were two different technical solutions of the aerodynamic panel between fuselage and left wing. For 109F 620 was panel 109.180-083, but for 109F623 it was 109.100-183. Of course, other parts were changed on fuselage, so so called "Triebwerkleidung am Rumpf" for 109F620 was 009.632 and for 109F623 it was 009.650. These parts were probably the aerodynamic panels on fuselage sides.

So, two solutions of engine covers of DB 605D (version of engine is important; it was made for DB 605D version) existed.

2) Engine bearers were same for DB 605AS and D, but DB 605A used different one. Right bearer for DB 605AS, D were only modified from the older one of DB 605A, but the left one had to be totaly new. A reason is clear - the larger supercharger of engine.

There is next smal complication yet - in 1944 was presented new modification of bearer, used different material - steel was used instead of electron. Some small changes of shape were made during the modification.

3) CWS plugs (I suppose, you mean the electrical connections on right side) were different between DB 605AS and D. You have to "track" a development of DB 605. Original solution of the cws plugs was made for DB 605A. They weren´t changed in case of DB 605AS, but complete "up-grade" of engine part were made in case of DB 605D. So, the plugs were changed too and the solution is characteristic for DB 605D (together with other changes).

Warmest regards


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