Dr I top wing control line inspection "hole"

Rowan Broadbent · 14 February 2006, 12:43 PM

Centrally located on the upper wing is a control line inspection hatch/hole.

Does anyone know if this was cellon covered, left open to the elements or covered with a fabric patch/lid?

TIA

Rowan

Fritz Kempf · 14 February 2006, 02:48 PM

Everything I have been told and seen, is that the whole is to see the work number on the spar. I had also thought that it was to see the wires where they criss-cross and make sure that they were not rubbing out. But I guess not.

Jim Bruton · 14 February 2006, 03:06 PM

i think it was indeed a celluoid cover

Cigogne · 14 February 2006, 04:03 PM

Correct, it was a framed celluloid window.

Dan_San_Abbott · 14 February 2006, 06:19 PM

Gentlemen:
All wing spars on all German aircraft had the small wood framed box.covered with celluloid. It has the ZAK approval stamp, serial number and date of manufacture. On the triplane it is only on the upper wing, the access to the spar centers on the middle and lower wing. You will find them on the under side of the center-section on both spars of the upper wing of a Fok.D.VII and on the top of the spars just outside the tread plates on the lower wing. All German aircraft had the spars so marked.
Blue skies,
Dan-San

Maxim08 · 14 February 2006, 06:59 PM

Further to Dan-San's comment, attached is the ZAK & window from the Knowlton D VII. I suspect that the Dr.1 was similar.
Regards,
Maxim08

Rowan Broadbent · 15 February 2006, 03:36 AM

The aileron controls ran in a continuos loop, as I understand it, so there would have only been one wire visible through the window, if it was an inspection port as well as to display the stamp, or would it have been entirely over the spar, as in the Knowlton example, with no secondary control wire inspection purpose? If so, to portray this in model form one could simply paint the hole wood brown with a dab of crystal clear over it, rather than hollow it out and add a control line along the back of the spar?

Rowan

Fritz Kempf · 15 February 2006, 05:10 AM

You would see no “control line” in the window the lines ran behind the spar. I have attached a pic of

LvR crash you can see the frame on the spar and that’s it.

Ed

snipe · 15 February 2006, 06:23 AM

Quote:

Originally Posted by Maxim08

Further to Dan-San's comment, attached is the ZAK & window from the Knowlton D VII. I suspect that the Dr.1 was similar.
Regards,
Maxim08

Here's a high res image (2048 x 1536 x 24 bits) of the same feature that I shot in August 2005 of the Knowlton D VII (6810/18).

There appear to be some annotations in pencil on the spar, I should have paid closer attention and made some notes...

Dan_San_Abbott · 15 February 2006, 10:24 AM

Rowan Broadbent:
There was a dual aileron control system in the Fok.DR.I, and independant of each other. You could loose one side and the other would function. I believe this was an Idflieg requirement.
Blue skies,
Dan-San