A minor plot wrinkle [spoiler]
[spoiler alert]
During the part where the plane and passengers are on the ground at Anchorage, there's a brief moment where the hijacker (Brolin's character) basically leaves himself wide open to being overpowered or, better yet, tossed off the plane. It's when he panics over seeing the van-load of photographers and runs down the aisle, pushes the two stewardesses aside, and stands at the open door and shoots at the van. He had his back turned to everybody behind him, totally unprotected. He'd put his grenade and electronic device away.
At this point, I'm thinking one or both of the two stewardesses could really have shoved Brolin right out of the plane, then shut the door before he could climb back up the chute. Security people were standing right below at the bottom of the chute, could have physically restrained him. Also, Captain O'Hara (Heston) was coming down the aisle right behind him, and could have rendered assistance in helping either to shove Brolin out or at least help shut the door if the two stewardesses had already shoved him out of the plane.