The AMA Safety Code specifically forbids any model weighing more than 55 pounds to compete in ANY AMA sanctioned Contest. Top Gun IS sanctioned. So, Top Gun does NOT allow heavier than 55 pound aircraft to compete!
The Turbine rule is the same. You can get your 55+ airplane inspected but you CAN NOT fly it in an AMA compeition. Just Demo flights only!
Stupid? Most Certainly! Why AMA feels you will have a greater chance of an accident flying in front of 500 people during a Demo flight rather than the same 500 people during a competition when the spectators are further back, is beyond any of us with half a brain! But, when we keep electing some District VPs or a President now and then, that perhaps haven't flown a model in 25 years or more, what can we expect? We are allowing rules for current pilots to be made by pilots of yesteryear, when the .60 sized Pattern Engine ruled the skies!
FT