Sorry for the mistake!!
On my sky high submission is talked only about plasma grenades, well frag grenades work too!!!
All you have to do is look down all the way and plant a frag grenade exactly behind the warthog and then jump on, it's not as effective as plasma grenades but its still fun.
One more thing, when you get on, try to jump back, making you go really far, I got over like this without extending the bridge.
SORRY FOR THE MISTAKE!!!!
We have more cheats and tips for this game here, Halo 2 cheats
Comments for this hint