From Halopedia, the Halo wiki
Retrieved from "https://www.halopedia.org/index.php?title=Flyboy&oldid=1333509"
Flyboy is a glitch in Halo 2 that allows players to store the lunge of an Energy Sword while in the seat of a vehicle. It is also known as "lunge storage" and has also historically been known as "sword flying." The glitch is only possible on the original Xbox version of the game. It was removed in Auto-Update 3 which is also included with the Halo 2 Multiplayer Map Pack though it can be restored by clearing the console's cache. The glitch works in both campaign and multiplayer.
The glitch is most easily performed by having a player wielding an energy sword sitting the passenger seat of either a Warthog or Spectre activate the sword's lunge when the reticle is red due to an enemy target being in range. Though more difficult the glitch can also be performed with any usable seat of any vehicle by activating the sword's lunge and getting immediately getting into the vehicle. The sword lunge will be "stored" regardless of whether the target or the vehicle the player is in moves The lunge can also continue to be stored if the player can get out of one seat and immediately enter another.
There are two effects that this glitch has. The first is that when the player exists the vehicle without immediately getting back in they will fly through the in the direction of the lunge they activated and typically fly much farther than the distance the target was at. The second effect is that in campaign the player will be immune to the timer for as long as they are in the vehicle.
The first effect gives it similar usage to Sword Flying as both allow players to travel fast through the air to distances they normally could not though some of the more elaborate setups allow for distances that are impossible even with normal Sword Flying and angles that are difficult to match. The two glitches can be combined to allow one to activate a lunge for storage from a greater distance. If this is done while sitting in a passenger seat however the player can not take advantage of scope weapons due to scopes not working.
Start a multiplayer game with at least two players on opposing sides on a map with both a Warthog or Spectre and a Banshee (Coagulation is recommended). Have one player player with an Energy Sword (Person A) sit in the passenger seat of the Warthog or Spectre ; the other player (Person B) should fly over them with a Banshee . As Person B flies over Person A, A should aim at them, attacking with the Energy Sword when their reticule turns red. Person A should then exit the vehicle and will then zoom through the air after the Banshee for quite a good distance; more exactly, they will travel to where the Banshee was when they first sword-lunged from passenger seat.