On Dec 23, 8:42*am, Bruce wrote:

Within the ability to measure I would say you could call it a Frustrum
of a cone. The vertical difference between the geometric straight line
and an ellipsoidal projection is likely to be less than your system error....


Somehow 'start cone frustrum' doesn't really roll off the tongue.

I remain curious about the "initial climb variance" across competitors
under the new rule versus the old rule. Does it pay to hunt around
inside the cylinder for the very best thermal or just head out on
course if you don't connect right away?

9B