When I used to do RC model flying up to the age of 17, it used to be quite a specialist hobby. Most models had to be built yourself, the radio equipment and engines were pretty expensive and the best route in was to join a club.
My local club at Tempsford was always pretty strict on flying rules, no overflying the parked cars or pits etc. But the cardinal rule was that if a real aircraft seemed to be looking to do a fly by or circuit then all models were to be landed immediatley, no matter what. This obviously wouldn't have been much help to a fast mover coming in at low level as we would probably only had 3-5 second warning but for the stunt pilots that made regular visits and also the wonderful John Jordan (our chairman at the time) in his wonderfull Stearman, it was easy to get all models down.
The trouble now is that with the advance in electronics and the introduction of ready made models, it is now quite easy for anyone to just go out and buy a fast model of about 40-50" span for about £100 and then fly it in the local park /common /sport field.
Model flying is no longer as centralised to specific flying clubs and models and it doesn't have the same safety standards either.
The electric models on sale now have a motor and battery that will probably weigh about 1 - 1.5 lb and that popping through your windshield could focus the mind. Also the batteris will be Lithium so if they get damaged they will catch fire or explode.....which is nice.
By the way, someone mentioned a 6-8 ft model as being large, that is a pretty standard size model now, large models now consist of 1/2 scale SE5a's and Fokker Triplanes, 30ft span Hercs and B-29's, 1/10th scale C-17 and also a 40% scale Pitts Special.
