It's expensive, loud, and potentially dangerous, but yes, should be legal in most places. Kudos to anyone who actually enjoys flying pulse jets and turbines, it must take some skill and calm to stand there and do low passes at 200+MPH with a fiberglass airframe and reaction engines that probably cost at least $4000, and then pull up at the last second and see it recede into a small dot in a near vertical climb. My spatial awareness of distances and stuff is pretty crap, and my coordination and reaction time are pretty average at best. This hobby definitely helps sharpen those things, but no way I could handle something like that.