Disappearing on The Covenant (Level)

On the level The covenant(level) you can disappear. after you kill the chieftain brute with the plasma cannon, once you get out side, jump on the friendly phantom. kill on of the elites on the plasma cannons and jump on the plasma cannon. after all the flood is killed off, the dropship will fly away, and once it reaches a certain area in the sky, you will disappear.