Here it is, page-144

You need some weight to it , otherwise would be no good to fly with a bit of breeze. Two years ago there
were in fashion those helicopters remember,,,,, and they were being flown inside shopping centres all over
the country... the small ones could not be operated outside unless there was absolutely no breeze... the
bigger ones held pretty good though. Anyway you like or dont like .... I m not trying to convince anybody , everybody to his/her own.