VTOL is only a suggestion I threw in - and the problems of them crashing over a populated area are the same as for light aircraft. But yes, I wold guess that they would have to be height-limited or to be under the control of the Air traffic controllers which would put one hec of a strain on the current system!

mm only today a light aircraft flew into someone's house... now multiply that by hundreds of thousand or zillions and ground zero would become the norm.... still could save the emergency services!

cn you imagine the joyriders n'all!

GOD BLESS!

Peace and Love,