Wait... If he just jumps off, and the ship is moving at any velocity, wouldn't he get run down by the airship?
How fast is that thing going, and does it have any jet-like engines to be sucked into?
No, because of the Law of Inertia: an object in motion tends to stay in motion. When you jump out of a plane, you do not drop straight down, you drop from what would look like the top of a bell curve. If you were to jump straight up and down on top of a moving train, you would only move back only a small distance because of wind resistance, if at all a noticeable amount. If you were inside the train, you wouldn't move at all.