ORIGINAL: MJD
As a model airplane flier since 1967, and as a rocket motor designer since the mid 1980's I can say that the last thing I would ever do is commit an expensive R/C aircraft to the fate of a homemade amateur KN/sugar motor in the back end. Those are best relegated to stick rockets and tube and fin sport rockets built from $40 of materials lying around the shop. The reliability of well made commercial rocket motors is even a factor to me in the decision to put one in an R/C aircraft - and I make them for a living [p.s. I don't care if people use other manufacturer's motors..]. I realize that we have to accept risk every time we fly (will I get hit, will the batteries crap out, will my elevator linkage come loose etc.) but adding homemade pyrotechnics to the equation makes absolutely ZERO sense to me, and honestly I think the suggestion to people to start messing with it in this forum is not a wise one. You can take me to task all you want for that opinion but I stick to my guns on the sentiment.
MJD
No, what I'm suggesting is that someone with too much money to spare decides that it might be cool to bolt a 18000Ns "commercial" motor to his Patriot, and then tries to make a low pass to "impress" the other folks...
A sugar engine may be low key to you, but it can be a lot of fun to other people.
If you realize that "your elevator linkage may come loose", you need to pay more attention to what you're flying. Linkages don't just "come loose"... If they do, you're doing something wrong. I've seen a couple of those at the field... whenever they show up, I make a run for the fence...