For those still interested in winglets I've come across some good info on winglet design in a book published by Vogel Aviation, ELEMENTS OF SPORT AIRPLANE DESIGN FOR THE HOMEBUILDER. It is based on the work of Dr.Richard Whitcomb, NACA Langley Research Center, in 1976. Also a Google search using Whitcomb and winglet as key words came up with interesting background. The book has the airfoil ordinates for the winglet.
Gene Lukan elu...@telusplanet.net