On Sep 28, 7:48*am, Evan Ludeman wrote:
Ye Gods, are we top posting or bottom posting in this thread :-)?

"Slippery" in the sense of elusive, ever changing, fiendishly difficult to calculate in real time.

2nd part: Yes, exactly, smaller circle (v min sink) yields better climb in most (classic small, round, columnar, strong at the core) thermals. *Uncenterable lift or really huge thermals are typical exceptions.

-Evan Ludeman / T8



On Friday, September 28, 2012 10:39:21 AM UTC-4, (unknown) wrote:
Please explain in *more detail. *Not clear what you mean by "optimum is going to be very slippery." *Are you saying that the benefit of slower flight and therefore tighter radius circles outweigh the losses from the higher sink rate? *Not trying to be a smart alec, I seriously want to learn from you more experienced guys. thank you.

Robert

On Friday, September 28, 2012 9:25:17 AM UTC-5, Evan Ludeman wrote:

Best climb isn't achieved at minimum sink. *Usually (90%), it pays (in climb) to fly slower than (load factor corrected) minimum sink speed. *The optimum is going to be very slippery -- it depends as much on the thermal characteristics, turbulence, etc. as it does on glider performance. *It's this sort of abstract, complicated, multivariable, analog "computing" that humans can still do better than machines (with enough practice). *Enjoy it while it lasts!

-Evan Ludeman / T8- Hide quoted text -

- Show quoted text -

The key point Evan makes (and I totally agree!) is that the strongest
lift is closest to the the center of a thermal, so flying slower
smaller diameter spirals will increase climb rate even though the
increased bank decreases the vertical component of lift. I had
opportunity to fly with some paragliders (with JS ) and even though
the paraglider min-sink isn't good, they outclimbed us because they
can fly such a small circle, and stay in the strongest lift.