Each person sleeps in a coffin that is also an autonomous vehicle. When the emergency alarm is raised (and the plane is on the ground), all of the coffins get

Each person sleeps in a coffin that is also an autonomous vehicle. When the emergency alarm is raised (and the plane is on the ground), all of the coffins get dropped off the bottom of the plane and they all drive their individual passengers off to safety. EDIT: Heck, I don't see why you couldn't also put a parachute on the thing.