I haven't looked at it lately but was wondering about this. On a show on the Science Channel called Master Blasters two teams were to make a rocket powered glider, the large ones not the Estes type. They were to be radio controlled. As it were they both failed, I suspect that one failed due to not enough fin area, and the other due to too much engine offset and low servo strength. But if they had worked they would likely have broken the 400 foot limit. I think they may have been ok because the 400 foot rule is only an AC and they had to get a waiver for large rockets. But I am not for sure.