On Saturday, February 21, 2015 at 1:49:46 AM UTC-5, Bruce Hoult wrote:
On Saturday, February 21, 2015 at 5:09:07 PM UTC+13, Bob Kuykendall wrote:
On Friday, February 13, 2015 at 9:49:02 PM UTC-8, Bruce Hoult wrote:

...but they lose badly to the new thin airfoils at high speed...

It's kind of a nitpick, but there's really nothing new about thin airfoils. What has changed in the last decade and a half is the cost-effectiveness of the structure required to implement them in competitive sailplanes.

Sure, carbon spars enabled them.

Spars AND skins. Torsional stiffness is a big consideration in these structures.
UH