he he 

If you look in the textures folder of the aircraft concerned you'll find the pilots' faces in one of the bmp files.

Your problem might be that it could be an 'extended' bmp that a normal picture reader won't be able to see. But often bmps like that are 'normal' 256 colour or 24bit bmps which you can see, open and edit.

If the bmp is extended then it becomes a bit more complicated - you have to 'read' it with DXTBmp.exe (from Martin Wright), convert it to a 'normal' bmp, edit it and convert it back to the extended bmp type that it originally was.

Not too difficult. Painters are doing it all the time without thinking about it