As an interested outsider reading this thread by chance, I can't quite believe the way fireflybob's initial point has been received.
Chuck, you say:
It is utter nonsense to believe that students cannot be taught to perform turns safely below 500 feet , altitude has no bearing whatsoever on safe turns.
Low level flight is inherently risky - less time to recover from a mistake, more chance of hitting the ground from a stall. Seems to me this is the very simple and sensible point ffb is making.
Low time students are concentrating hard on controlling speed with attitude on the climb out - add the need for a banked turn at 100' and the task becomes harder, and because of the low altitude the outcome of an error in speed control could be fatal. Now I agree that with good training low time students should be capable of executing the turn safely, but I still think the risk has increased compared to a turn at 500'.
Chuck, another statement you make:
I can not remember ever seeing an airport anywhere in the world where a turn after take off was required that put airplanes at risk.
ermm....theoretically maybe, ie, when the performance tables are analysed in the safety of a quiet office, but there are certainly some where one does feel the turn plus say an engine failure could make things rather interesting. Why do you think airfields are Categorised A,B and C? Its a risk assessment in a sense, and some airfields will require recent experience, or be deemed training Captains only. Funchal springs to mind.
So coming back to fireflybob's original point, it seems to me a perfectly valid and simple point he is making - namely, the low hours student's risk exposure is being increased by this turn.