Bf 109K Data Plate Location

[klemchen]

Hello,

to me the photo is sensational. I had always been told (and until now believed) that there has never been a K-4 by Erla. There is another photo of a K-4 with an Erla cowling on p. 44 in Poruba's and Mol's JaPo book on Me 109 K camouflage and marking. I had taken that aircraft for what it was but thought it must have been the result of exchanging the cowling in the field, which should have been easy apart from adapting the port fuselage bulge to the Erla cowling. Now this odd theory can be abandoned.
I wonder where Steven Sheflin's other K-4 by Erla can be found.

Regards,
klemchen

[Rasmussen]

Originally Posted by klemchen

I wonder where Steven Sheflin's other K-4 by Erla can be found.

Another Erla K-4/R6 is documented with BAL acceptance flight from February 16, 1945. It was the W.Nr. 570 362. I gave Mr. Prien this information in the beginning of the 90's and he used it for his publication to the Bf 109F-K.

Originally Posted by veltro

And it shows that apparently Erla-built K-4s had the same rectangular panel (and eventually no chin bulges and differently machined upper and lower engine cowl) than on their peculiar G-10s...!

Yes, the Erla K-4/R6 had the same engine cowling like the Erla G-10 (without the chin bulges). It seems it was the planned style for all K-4's but Erla got the tools alone.

Interesting too that mmoustaf mentioned the picture in his posting from December 12, 2008 .... unfortunately in the wrong forum - the allied forum.

Best wishes
Rasmussen

[harrison987]

question...

You are mentioning that Elra built K-4's did not have Chin Bulges...if this is true, how did they bypass the extra space for the return oil lines on the 605D engine?

[veltro]

Originally Posted by harrison987

question...

You are mentioning that Elra built K-4's did not have Chin Bulges...if this is true, how did they bypass the extra space for the return oil lines on the 605D engine?

Through a complete redesign of the lower cowl which managed to enlarge and deepen it just enough to allow keeping smooth contours.

It is a quite well known topic, being enlightened at first by Jean-Claude Mermet and further deepened by others.

The appearance of the Erla G-10s was so "perfect" that only at some viewing angles the new contours of the lower nose section could be noticed, this resulting the wrong identifications of G-10/AS for several years.

Here it is how I explained that in my last book:




I guess my friend Rasmussen will be able to supply more details.

Hope it helps

[D.B. Andrus]

One more step in the documentation of Erla-produced K-4's. These fuselages appear to be the Erla produced K-4/R6 type. Please note the arrows indicating the MW hatch on the starboard side and the Erla-type bulge on the port side of two of the fuselages. Also, the fact the photo was taken near Plauen probably indicates the assemblies were on their way to an Erla assembly facility.


Photo caption: "...photograph...taken on April 17, 1945, near Plauen, Germany, reveals at least fifty fuselages which failed to reach their final assembly point."

Note: The attached photo is from Messerschmitt "O-Nine Gallery", by Thomas Hitchcock, Monogram Aviation Publications, 1973(OOP), page 16.

[Otterkins2]

The last number in the werk Nr appears to be a 5....570 375. Amazing what you can do with photoshop tools. Here it is again using the shadow/highlight filter....

[klemchen]

Hello,

the contribution by Ferdinando D'Amico on the various DB 606 AS/D cowlings encourages me to post here what I call "my big Erla cowling problem", with a few more remarks about the background, which at the same time can be viewed as questions asking for confirmation or rejection. In advance I apologize for being somewhat lengthy.
The Regensburg Me 109 K cowling (Mermet type 100) was still pretty much based on the Me 109 F cowling. The lower cowling was basically the same, except that a deeper oil cooler was inserted and the so-called chin bumps were added. In particular, it was symmetrical. The upper cowling halves were asymmetrical because the large DB 603 supercharger did no longer fit inside the DB 605 A cowling. Therefore the port upper half had to be reshaped to accommodate it, and at that occasion the bump over the breech of the port MG 131 was made integral to the cowling half. At the same occasion also the bump over the starboard MG 131 was made integral. Behind these integral bulges two shallow elliptical blisters were attached to the fuselage sides (accompanied by a widened so-called weapons cover in front of the windshield); these extended downward only to slightly above the wing fillets. Since the rear part of the upper port cowling half was wider than a normal DB 605 A cowling but the port lower cowling was not, what some author has called "an untidy construction" was employed for the transition of the upper half to the lower part behind the exhaust stubs. The forward part of the upper cowling remained the same as for the DB 605 A; on starboard this part extended backward to the normal panel line, while on port that panel line had to be moved forward some length because of the larger bulge for the supercharger. Because of combining the normal forward part with the wider integrated bulges the shape of the upper cowling contained some concave portions.
Since these were not aerodynamically optimal, Erla redesigned the whole cowling. The new cowling (Mermet type 110) did not have any concave curvatures; that is why the gun throughs from the side appear much narrower as before. In order to avoid the "untidy construction" aft of the port exhausts, the lower cowling was made wider on port and thus became asymmetrical. As a consequence, the port blister on the fuselage side behind the engine compartment had to keep about the same distance from the original fuselage side over the entire height of the fuselage side; that is why its rear edge could no longer be elliptical but had to become vertical. This construction must have demanded also a new forward port wing fillet.
That the lower half of the forward cowling ring (immediately behind the spinner) had to be widened and deepened on its lower sides has been pointed out before by other contributors. It was probably also deepened slightly in the middle, so the lower cowling line between spinner and oil cooler would appear slightly bulgier than on other 109s. Ferdinando D'Amico has drawn it that way, and I think it can be seen weakly on some photos. Some time ago somebody showed me a Messerschmitt drawing comparing the lower cowling lines of the "Me 109 K" and of other109s. Since the lower line of the Regensburg K was essentially the same as that of the "normal" F/G, the drawing must have shown the lower line of the Erla cowling. The "K" lower line was about 1 or 2 cm lower than the other one over its entire length, until it met the underside of the forward wing fillets (which also were forming the rear part of the bottom engine cover). When I later asked that person to show me that drawing again, he could not find it among his lots of Me 109 stuff, so I cannot say more about it.
This is where "my big problem" is entering the scene: The Erla cowling also got a new oil cooler bath. Many people have claimed that the radiator underneath was shallower but wider than the Fo 987 of other G-10s and K-4s, but I doubt this. I admit that the oil cooler of the Erla cowling appeared shallower than that of a "normal" G-10/K-4, but this could as well have other reasons: Assuming that a Fo 987 type radiator was installed in exactly the same position with respect to the engine as usually and that the bottom of the Erla cowling was indeed slightly lower than on other cowlings, then the oil cooler cover would appear shallower too. Another hint, however weak, that the Erla cowling was equipped with the Fo 987 is given by the famous Messerschmitt drawing of an Erla G-10, which was published in many places, e.g. in the booklet on the various Me 109 G cowlings by Jean Claude Mermet. Although quite crude in some details, that drawing is very precise with respect to the basic outlines, and the front opening of the oil cooler on it has a width corresponding to about 46 cm. For comparison, the duct of the Fo 827/870 oil cooler of earlier Gs was 462 mm wide at the base and 448 mm at the top, and the Fo 987 must have been similar. Of course this correspondence may be due to the crudeness of the drawing. I also tried to determine the width of the oil cooler by taking measurements on a photo that is showing an Erla G-10 exactly from the front by relating it to the length of a propeller blade (1.5 m) and to the wing span (9.92 m). Because the propeller was closer to the photographer than the oil cooler it yielded a width smaller than 46 cm, and because the wings were further from the photographer they yielded a greater width. Unless the exact distance of the photographer from the aircraft is known, this method cannot be refined to give a precise answer.
My main argument is that it seems highly improbable that at that stage of a losing war the logistics situation would be aggravated by introducing yet another type of radiator. Of course this can be said about a new type of cowling as well, but Erla were making their cowlings themselves. I do not know this for sure but I imagine that this does not hold for their oil coolers as well and that they had to order these from some subcontractors. If somebody could confirm this, I would consider my problem as very probably solved; otherwise it would remain open.
There are two more questions: On photos of Erla G-10s I could not detect the small vertical strut in the front of the oil cooler that was there on other Me 109 F/G/Ks. Finally, I have come to know a number of names of Messerschmitt engineers but never heard of the creative engineers at Erla, who not only constructed the most advanced Me 109 cowling but before that had designed the Erla cockpit hood, which became common for all late 109s.

Again apologizing for being so lengthy,
klemchen

[Rasmussen]

Originally Posted by klemchen

Finally, I have come to know a number of names of Messerschmitt engineers but never heard of the creative engineers at Erla, who not only constructed the most advanced Me 109 cowling but before that had designed the Erla cockpit hood, which became common for all late 109s.

The answer is quite simple ... Erla was an so-called "Nachbaufirma" without an own design department. There was an department to adapt the Messerschmitt drawings for specific conditions in Leipzig but not more. The leader of this department was the known Franz Xaver Mehr (he constructed some light prewar-oneseater). Erla Leipzig got the tools for the well known cowling but it wasn't developed by Erla.

Best wishes
Rasmussen

[RolandF]

So why didn´t the other production sites at Vienna and Regensburg switch to these improvements?
On the other hand, at least the Mtt Regensburg production lines at Waldwerk Hagelstadt and KZ Flossenbürg were anything else than "sophisticated" production sites so the older jigs and tools would be easier to use by the unskilled workers there...

Regards

Fran