I'm using the FSX Patriots Jet Team L-39 as the example.
![Image](http://i.imgur.com/ejUv5.jpg)
Now, for start. Depending on the plane you want to do or are doing you can have two types of glass texture bitmap: a simple solid color square or individual texture for the glass parts (like the one I used in the L-39 and you can see it in most FS add-ons) or have the glass mapped into the main texture sheet along with all the other plane parts, like in most of my original planes and some other, not many, FSX add-ons...
In this example I'll be using the solid color square bitmap.
So go ahead and create a 256x256px square and fill it with the color you want your glass tint to be and name the file "glass.bmp".
In gmax/3ds max create an FSX material and add that bitmap to the diffuse channel and specular channel.
Lower the opacity to 15% and increase the Glossiness and specular level to 15.
Now scroll down to the "FS Extended Params" section.
SPECIAL FUNCTIONALITY
"Blend Diffuse by diffuse alpha" checked (this way you can adjust the transparency of the glass through the alpha channel of the texture);
"Use Global Environment Map as Reflection" checked.
Reflection Scale=70
Specular Map Power Scale=256
BLOOM
Allow Bloom checked
No specular bloom checked
FRAMEBUFFER BLEND
Click "Set Default Transparent"
Source Blend= SrcColor
Destination Blend= InvSrcrAlpha
MATERIAL ALPHA TEST
Z-Test Alpha checked
FINAL ALPHA BLEND
"Set final alpha value at render time" checked
ENHANCED PARAMETERS
"No Shadow" checked
And that should do it for the material. Apply it to the model's glass and add a square UVWmap modifier.
Export the model and open the texture bitmap with DXTBmp;
Go to Alpha/Send Alpha to Editor. It should open Paint.
Fill the white square with a medium dark grey.
I used 82,82,82 RGB for the L-39.
Save the bitmap as DDS and place it in the "texture" folder of your aircraft.
Run FSX and check the result. You can change the reflection/transparency to adjust to your plane.
Any doubts/problems, post them here!