Warbird Information Exchange

Hello All,

I'm trying to interpret some Messerschmitt Me 109 parts drawings and was hoping somebody more knowledgeable could give me a few pointers.

Here are the questions:

1) Tolerances. On most dimensions, there are none and no tolerances in the title block. Does someone across the pond (or anywhere else) know what German practice was in this regard? Did the Germans have an industry-wide standard for tolerances or one peculiar to Messerschmitt?

2) The meaning of the phrase "Durchzüge nach Werkzeug Nr. 3 MeN 50715".
Babelfish gave me "through courses after tool nr. 50715" which doesn't tell me a lot.


3) The meaning of the phrase "BfN 13855". What does BfN stand for? "Bayerische Flugzeug Nummer"? The number of what?

All this information came off the same drawing.

Thanks for any hints.

Ray Crawford

Ray

Ask here:

http://forum.12oclockhigh.net/forumdisplay.php?f=8

Dave

Hello Ray:

I've noticed you've asked some questions regarding FAA regs. as well. Let me say this; if historical significance isn't important, the AC-4313 provides tolerance limits for acceptable repair methods on aircraft.

The forum at the 109Lair gets some very knowledgable people

http://109lair.hobbyvista.com/index800.htm

Thanks for all the Replies!!

Ray

Sheesh and I thought the Mustang blueprints were a pain. At least there in english.

What format does one find German blueprints in? The American stuff is all on old microfilm. A lot of it is in pretty sad shape.

-jim lee

The ones I have are drawn in reverse projection (the part is shown from the rear instead of the front) along with side-views, the usual title block with bits of info and signatures of long-departed engineers, material callout, and thanks to many very helpful like-minded people, I know that special tools are called out by number when applicable. Most dimensions are called out without tolerances but it looks like Andrey has a handle on that. Drawing notes appear when necessary but not in large numbers along with detail views and section views. Not very different from American prints. Pretty thorough and business-like once you figure out how to read one.

Ray

Are we talking complete set of working drawings or just overview of sides and ends?

One reason why I ask is.. Are you maybe planing on building a BF109 perchance?

-jim lee