Here is the text from the document. For some reason, the images are not copying into this post. The PDF is too large, and when I tried to ZIP it, the file was not allowed. I use these steps for both FS2004 and FSX prop textures. I hope this helps.
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Correcting Propeller Displays
on FS2004 aircraft used in FSX with Service Pack 2
an Illustrated Tutorial (Sorry)
This is a well known issue which has been addressed in several forum posts. As a “picture is worth a thousand wordsâ€, I thought an illustrated tutorial outlining the correction procedure might be useful.
The Problem:
(Dark circle props)
The Solution:
(Textured props)
This tutorial outlines the procedures I used to correct the propeller issues with the Douglas A-26 Invader aircraft from Sim-Outhouse: (a26soh.zip). There are corrections available for the fuselage issues also and those are noted in the appendix of this tutorial.
While this tutorial use the A-26 as an example, the concept will work on any FS2004 aircraft which exhibits the same propeller problem.
-- Tools needed
Martin Wright's DXTBMP program:
http://www.mnwright.btinternet.co.uk/programs/dxtbmp.htm
You may also need mwgfx.dll from his site in order for the DXTBMP program to funtion properly:
http://www.mnwright.btinternet.co.uk/graphix.htm#dlls
-- The Procedure
1. In the texture folder of the offending aircraft, locate the .bmp file
which displays the propeller. In the case of the A-26, that file is
named spinprop.bmp. Open that .bmp file in the DXTBMP program.
2. Assign an Alpha editor to the DXTBMP program. MS Paint works just
fine for our purposes. This can be automatically set as follows:
3. Send the Alpha Channel to the editor:
4. MSPaint will be opened to view. (Or the editor you choose)
Double left click on any color – see the position of the cursor in this screenshot.
5. The color selector will now display. Select "Define Custom Colors". Drag the slider on the right down so a value of 30 is shown in the
Lum: column. That is my preference - the lower the number, the more transparent the alpha channel will be.
Hit OK. Then use the “fill bucket†to fill the white Alpha area with the revised color.
After it has filled with the revised color, select "Save" (not "Save As"). Then Exit MSPaint.
6. DXTBMP should now be on your screen. From the Alpha menu, select "Refresh Alpha"
The Alpha window in the upper-right corner will change from white to the revised color you created - that's the transparency value (the darker, the more transparent).
From the File menu, select "Save as" -> "Extended Bitmap".
Then in the “Type†dialogue, choose "DXT3". Save it using the original filename. The screenshot below shows that I saved it to my Desktop.
The result will be a revised .bmp file with the alpha channel made quite transparent allowing the propellers to display properly in FSX with Service pack 2.
7. To complete the process, simply replace the original .bmp file with the one you have just created.
-- This process will work on other .bmp files when you wish to make an area transparent. Experimentation is half the fun!
Appendix
The corrections to the A-26 fuselage can be downloaded as follows:
A26B with guns: http://www.flightsimonline.com/downloads/a26bx.zip
A26B without guns: http://www.flightsimonline.com/downloads/a26bngx.zip
A26C with guns: http://www.flightsimonline.com/downloads/a26cx.zip
A26c without guns: http://www.flightsimonline.com/downloads/a26cngx.zip
Credits
Martin Wright for his excellent DXTBMP program.
The various forum members who have outlined this procedure in several different postings.