You guys do know that AMA is not the law, and you can build what ever size planes you want to, AMA can't stop you , you just won't be flying them at AMA sanctioned events , or flying fields that have chosen to follow the AMA guidelines . The fact is that almost all insurance risk is based on the "POSSIBILITY" of claims not the actual history of claims, Larger aircraft can or would cause more injury if crashed into a crowd than a smaller aircraft, lets face it if a Cessna 150 crashed into the World Trade Center, in most likelihood it would still be standing. Even at 55 lb plane has the potential to do more damage than a 20 pound , just on size alone, hurting 6 people in one incident is considered worse than hurting one or two. The extent of injury is not as important, a indoor plane could take out an EYE, but a 80 pound bomber with 120 inches of wing could take out a dozen. No matter how much you prove a bigger plane is less likely to cause an incident , you will never convince the insurance people that the potential of hurting many people in one incident is better than the hurting one or two in a incident. Same goes with faster planes, I have a prop powered plane that weighs less than 5lbs, can probably do around 140 mph, just as fast as some Turbine , IF there was an incident where my plane went into a crowd it could just as easily kill someone as a 30 pound Turbine, but 30 lbs carries more momentum , a Turbine powered plane has more of a chance of catching fire, it would probably hurt several people where mine would probably stop after the first impact. so the risk(or amount of money paid out) PER INCIDENT, is considered higher.

I am by no means aginst the AMA considering ways to allow the over 55 planes at thier events , I am sure there is a way without causing a rift with the insurance people.