I've read Alan Steele's book Chronospace. What happens if the airship lands without mishap? No radio broadcast about a disaster? What happens next? Does the ship explode in its hanger? What happens to History? I would think that not much change in politics and world events unless someone gets the idea to shoot Hitler. It is not implausibe because in Nov. l919 Hitler was nearly killed by a bomb after a speech but he left 20 minutes before. Maybe the bomb was the work of the SS>