ORIGINAL: EASYTIGER
Yeah, I'm just wondering who answered "11 or more"...I'm sorry, it's just either a really daft interpretation of the question, or some alternate universe of Happy Modelland where there are kids and their pipe-smoking dads all enjoying park flyers in each and every soccer and baseball field you pass. It's actually pretty rare to see a kid playing with a model airplane nowadays, which is why you can always find cheapo Estes and Air Hogs arfs in the discount bin at Radio Shack and Toys R Us. They just ain't a hot item.
And they are all on 27 or 49mhz.
I'm not particularly scared of the "park flyer menace".
Here in NYC, there is no flying allowed in Central Park, anyway!
I think you have provided the parkflyer solution, ET....or rather shown the solution is that there is no solution needed because there is no problem. No problem not just because park flyers don't see any problem, but more so because there are no park flyers. How elegant.
BTW, has it occurred to you that what you see in your environs may not be typical of the rest of the country? After all, NYC is something of an alternate universe in its own right. Like, how many FF models have you seen in NYC in the past month? How about turbines? For that matter how many model flying sites, period?
Abel