Factual error: Little over an hour into the movie, Yellowstone blows up into a huge volcano. The pyroclastic flow that follows the camper is going at such a speed (the speed of the flow can be seen when the plane is in the air) that it would have overtaken the camper well before it has reached the plane. Even if the cloud would have been slowed down by hills, it would have, after the camper reached the plane, overtaken the plane long before it could take off.
lionhead
25th Nov 2009