Ride in a Pelican

On the level Metropolis in Halo 2, when you come to the part of the level where there are two ramps and three Wraiths (depending on difficulty), destroy the Wraiths and all enemy'. You should hit a checkpoint and then a Pelican will come to the bridge closest to the marine building. Go up the stairs and as the Pelican is dropping off the Marines, jump up and to the left of the Pelican and hold X and now you go for a little ride. About a minute into the ride you should reach your destination. You will be thrown from the Pelican and you should see it flipping uncontrollably. When you get close to it, it should say hold X to flip Banshee and when you do it will keep on flipping.