This code can only be done on 2 players. At the beginning of the level: 343 Guilty Spark, have both players stay inside the Pelican by rapidly pressing the grenade button until both players throw the grenade. The Pelican will soon fly off with both players riding in it. Once the Pelican gets to the area with the 2 dimensional trees, have one of the players jump out. While the player that jumped out is falling, on his screen it will say: "press X to flip Pelican". Have the player that jumped out rapidly press the X button. If done correctly, the Pelican will miss the spot where it normally would land. Have the player that stayed in the Pelican get out as soon as it lands. Look on the player's screen that just got out of the Pelican. On his screen it will say: "press X to flip Pelican". Press the X button and the Pelican will flip over on it's top. Press the X button again and it will flip again and land normally. From here, you cannot flip over the Pelican anymore, however, you can melee it with your weapon and it will slide, just like any of the vehicles that you can drive. This glitch cannot be done on 1 player because if you jump out, the Pelican will disapear, and if you stay in, the Pelican will land safely and you will not be able to flip it over.