Model rockets launch and fly autonomously, and can be either actively or passively stabilized. Their powered flight is generally confined to vertical trajectories. Drones fly predominantly horizontal trajectories, autonomously or under operator control, usually use propellers for propulsion, and have weight, flight ceiling, and speed restrictions when piloted recreationally 55 lbs, 400 ft, and 100 mph. Rocket powered RC planes generally fly trajectories including significant horizontal components, under operator control, and can exceed drone speeds (this video).
I am curious as to under what circumstances an aircraft crosses into these various regulatory categories. Specifically, in the video, the rocket powered RC plane crashes because of an early roll that the operator was unable to correct manually. Would integrating active, computer assisted stabilization make the plane a drone? From another angle, there are autonomous quadcopters, and autonomous model aircraft - when do these become drones, and thus subject to the weight, flight ceiling, and speed restrictions?
To provide a unified litmus test for the exact boundaries of these legal classifications, I inquire: Would an autonomous (in the drone sense of the term, meaning able to be brought under operator control), rocket powered model airplane be considered a drone, model rocket, or RC plane, and by which regulations, or combination thereof, would it have to abide?