I think I figured out how to do it! I can get the Armor Lock and I can get on top of the Pelican, but I can't get to where he is in the vid and I always end up sliding off...
"If at first you don't succeed, try, try again!"
EDIT: There seems to be a "glass ceiling" on the level, preventing me from getting to the back of the Pelican, and also "pushing" me off when the Pelican flies away... It's even there when I'm in Theater; I can't seem to go above this "ceiling" even with the flying cam...