As a participant in the speed data gathering at Hearn this past weekend, I'd like to chime in on this subject with a few points of observation.

Of the dozen or so airplanes that participated in determining average and top flying speeds, only two were able to break 200 mph.

All top speeds recorded were achieved after a dive with up to full power followed by a gentle pull to level flight over the trap at approximately 40' AGL.

At least one of the airplanes that broke 200mph had less than a .9:1 thrust to dry weight ratio.

I know that at least one of the planes had a greater than .9:1 thrust to dry weight ratio, and it was not able to break 200mph after two very aggressive attempts.

Several flights each were made over the trap by some of the planes, and the recorded speeds seemed consistent.

Some that turned in lower than expected recordings in fact were easily overtaken in the pattern by those that did turn in higher recordings.

During the weekend there was a guy practicing with a glow powered pylon racer. Now that was scary! I'm not kidding. That thing was pointed at me at least once every lap and made me quite uncomfortable.


Conclusions?

The speed trap seemed accurate enough for the intended purpose.

You had to try very hard to break 200mph from a dive. Level flight max achievable speed would likely be much less than those recorded this past weekend, and probably none would have exceeded 200mph.

The thrust to weight ratio rule is meaningless when it comes to governing max achievable speed.

Speed limiters would seem unnecessary since most jets would not exceed 200mph on a regular basis.

I have a question for you all and the AMA rule writers. What is the difference between a crash at say 80mph and one at 250mph when it comes to risk management?


Comment: I can't keep up with the little jets that go 200mph anyway, so, if it makes the AMA feel better, I don't care if they set the limit at 200mph so long as the rule does not also force me to install an expensive speed limiter that is not needed in my case anyway. I also fail to follow the logic that says if I use a single turbine, it must not put out the same thrust allowed for a multi turbine powered model. I say let the model manufacturer publish the thrust and speed limitations for their products and leave it at that. If you want to exceed these thrust limitations by use of a speed limiter, then so be it. I just want to be able to pull vertical at takeoff and could care less about exceeding 200mph!



Cheers!


Reid