On Monday, November 4, 2013 1:02:52 PM UTC-5, Evan Ludeman wrote:

Greg Cole, 2012 Barnaby lecture http://www.youtube.com/watch?v=Ln9fuR8uwIc

Discussion of DH starts about 17 minutes in.


I'll second that. This is a fascinating talk by a very smart and competent guy.
Anyone interested in sailplanes should take a look.