On the second campaign mission, Winter Contingency, one can disable and commandeer a Falcon for their own use. To perform this glitch, start Winter Contingency on Normal difficulty, at Rally Point Alpha. Play through the level like you normally would until you get to the first structure. Obtain a Plasma Pistol by killing a Unggoy, Kig-Yar, or T'vaoan. Once you have done so, look up at the cliff to the left. You should see a Falcon hovering above the cliff. Charge a superbolt and fire at it to stun it and make it fall down the cliff. This should make the Falcon flip upside down as it is tumbling down the cliff, making Troopers inside of it, and the pilot automatically get out. (You cannot kill the pilot of the falcon by any means except destroying the falcon, thus you must force him out of the cockpit.)
Once the falcon stops, flip it (if need be) and enter the cockpit. If you enter the side, you will not be able to get back out, forcing you to restart the mission. You can also let allies in the falcon. Like in the mission New Alexandria, you have a main gun on the front of the falcon. To continue the mission, you have to lodge your falcons wings inside the two "prongs" that stick out of a Spirit dropship, as there is an invisible wall near the cliff where the falcon normally takes you, and you need the power of the spirit to push you through it. Once you've done that, you are free to explore anywhere you want! Note that if you use the Falcon to try and finish off the level in the courtyard, you will have a very limited flight ceiling and you will be unable to get out of the falcon unless it gets flipped.