If you just want Sky Trak game to display in 4:3 on a 1080P display. Since the game does not let you specify a specific full screen resolution we found this method to force it into 4:3 aspect ratio. I would recommend you do this while actually in the game itself and not the menus as the game HUD/info seems to be cropped/trimmed as you resize the window.
3.Press Alt+Enter again to full screen SkyTrak which should now keep the aspect ratio previously set.
If you want to have all windows applications to be forced to a 4:3 resolution (not ideal if connecting a second 1080P monitor/TV)
Hope this helps.