- Play through the mission until you get control of the crater and set up your base.
- When the Evac Pelican Pilot says: "Evac Pelican inbound with UNSC survivors, cover us," and when Bravo 29 says: "Pelican Bravo 29, got a few stragglers for ya, requesting cover," press Right on the D-pad.
- The crosshair will move to the Pelican, but it is not inside the level yet, so you will be 'Out of Bounds'. You can move the crosshair around, but you will not be able to push the crosshair back into the level, or out much further. You can rotate the camera to see under the level as well.
- To go back inside boundaries, press Left or Down on the D-pad to go to your Army or Base.
If a Hornet (or Skyjacked Banshee) is under control of the player, when moving the crosshair out, it is possible to circumnavigate the level with an air craft. If you leave the Hornet/Banshee outside, you can send additional forces (other Hornets and Banshees) outside the Boundaries as well.
The logic behind this glitch is if an Alert is triggered, an Alert Location must be present, along with its "circle" on the Mini-Map. If on the Mini-Map no Alert Location Circle appears, the Location is outside the level, and the Mini-Map's boundaries, so it does not display it. Jumping to the Alert Location by pressing Right on D-pad is the way to see the Alert.