K -specific technical markings?

[JST]

Been putting together a 109 K stencil for technical/maintenance markings, but besides the usual stuff about tire pressure and such, some markings have bothered me for quite a while.

 

So far I've only seen these on K's and was hoping people here would have knowledge about them.

 

This one, on the edge of the radiator flap, is somewhat clear to interpret, and it says: Klappen-Ausschlag auf 220 m/something begrenzt, which Google roughly translates to "Limited flap deflection to xx"

 

 

Another pic from what I believe is the same info:

 

Here's something else scribbled on the edge of the radiator flap, perhaps an abbreviation of the same text?

 

Edited October 6, 2014 by JST

[f4l0]

On the left side ( and right above the flaps text) it seems to me that this is "Nicht betreten" which means "no step".

[JST]

On the left side ( and right above the flaps text) it seems to me that this is "Nicht betreten" which means "no step".

 

Obviously, but this is clearly found on all 109's starting from atleast the Emil, but I haven't seen the flap info on anything but K's.

[Kurfürst]

I am almost certain that it reads "Klappen-Ausshlag auf 220 m/m begrenzt", m/m being for milimeters and meaning that the radiator flap opening is limited to 220mm wide. That's roughly 2/3s of the max opening (350 mm) of the 109G

 

As to cause of this note or solution, I can only guess this was to limit drag.

 

I have seen the 220mm max opening on some original drawings for 109K, and I can guess that perhaps the original 350 mm radiator opening was excessive and found unneccesary. Perhaps it means that this note refers to the implementation/installation of an improved radiator with optimized flow ("verbesserter Kühlerdurchlauf"), that mentioned in 1945 January performance calculation for improved propellers.

 

http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-17_conditions.jpg

 

Another possibility is that IIRC the 605D engines fitted to the 109K-4/G-10 had increased temperature limits, which the radiator could maintain at 220 mm max opening.

 

The K-4 may have sported a new radiator type of 36 sq. decimeters area, though there are some who doubt this and maintain that it used the same as 109G series.

 

Opening the radiator fully came with considerable drag, so limiting their maximum opening would also limit drag rise. See this drag chart for January 1944 for 109G

 

[JST]

I am almost certain that it reads "Klappen-Ausshlag auf 220 m/m begrenzt", m/m being for milimeters and meaning that the radiator flap opening is limited to 220mm wide. That's roughly 2/3s of the max opening (350 mm) of the 109G

 

As to cause of this note or solution, I can only guess this was to limit drag.

 

I have seen the 220mm max opening on some original drawings for 109K, and I can guess that perhaps the original 350 mm radiator opening was excessive and found unneccesary. Perhaps it means that this note refers to the implementation/installation of an improved radiator with optimized flow ("verbesserter Kühlerdurchlauf"), that mentioned in 1945 January performance calculation for improved propellers.

 

http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-17_conditions.jpg

 

Another possibility is that IIRC the 605D engines fitted to the 109K-4/G-10 had increased temperature limits, which the radiator could maintain at 220 mm max opening.

 

The K-4 may have sported a new radiator type of 36 sq. decimeters area, though there are some who doubt this and maintain that it used the same as 109G series.

 

Opening the radiator fully came with considerable drag, so limiting their maximum opening would also limit drag rise. See this drag chart for January 1944 for 109G

 

Excellent information, thank you!

 

I didn't even think of millimeters, since that is an odd way to write it down. Certainly makes the most sense.

 

Know anything about the white text on the last picture? Location seems to suggest similar info.

 

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On other markings, did 109's with MG131's have any dedicated air tanks for pressurized air like the earlier models with MG 17's. Being elecritc, it would probably eliminate the need for pressurized air, and I haven't seen any "Pressluft für MG" markings on 109's with MG131's

[Aufpassen]

It would be Klappenausschlag with a c in there

[JST]

Missed the "c" there, thanks.