Press Alt-o when in flight, a special menu appear.
Try 'WC3 -mitchell'
When you enter this you'll hear someone yell "mitchell" during the scene
of Blair getting ready to launch. Target an enemy and press W.
You'll see a message saying "1 object destroyed" in the upper left corner
of your screen each time you use it. If you're using UNIVBE you'll get a
thin line of video garbage near the bottom of the screen. Works on
fighters and Capital ships. Don't know if it works against ground targets.
