Halo 3 on XBOX 360 help!!!!!?

[Beans]

i recently got halo 3 for my xbox 360 and i was wondering how you jump on the plane! i have tried a million times but i cant jump on!!! (and then they usually leave us. )

PLEASE HELP!
1, when we are at the buliding with all the tvs, and then when we get all the aliens, a plane comes to get us, but we jump but just come back down.

 

[ffxfayth]

Which level are you talking about?

 

[sk8er_josh_4ever]

What plane? Could you be a bit more detailed cause there at least 3 other different types of ships in Halo 3

And plus, if your talking about the Pelican, those can't be boarded since they are just transportation ships to get you to next part of the level/mission