Originally Posted by learn2turn

But if the loop is big enough in relationship to the speed of the plane and round, then down elevator will needed and the plane will pull the negative Gs in the top of the loop.


I think the gist of this thread is that it's better to make the speed of plane such that the plane does not pull negative Gs in the top segment. At least that's what I learned from it. It's academic that it can happen at any speed if the loop is large enough.