Suspended dropships

From Halopedia, the Halo wiki

In Halo (Halo: Combat Evolved Level), there's a script glitch that affects the Covenant dropship that appears in the valley with the partially buried structure. It drops off some Elites and Grunts next to the crashed lifeboat near one of the entrances to the valley. However, if you arrange to be standing on the high ground just inside the other entrance when the drop-ship arrives, it will hover indefinitely over the lifeboat until you leave the area (either deeper into the valley or out of it will do). During this interlude, the Elites riding in the starboard personnel bay of the dropship are immobile and utterly defenseless against sniping.