The many discussions about various airfoils and the Ashok ones, plus the recent discussion about the cusp, cause me to recommend highly to all list members, a book by Harry Riblett entitled GA AIRFOILS, A Catalog of Airfoils For General Aviation Use. It is available as part number 13-18725 from Aircraft Spruce & Specialty at ph 877-4-SPRUCE. It includes a comprehensive, easy-to-understand discussion of things airfoil. It is good to read first before other texts, so you have an appropriate amount of jaundice before reading them. The cusp is discussed. Mistakes made by NACA on their 6-series laminar flow airfoils are discussed. I believe KR builders would find it very interesting.
-Lloyd Schultz
