It is my understanding that the airfoil on the Four Star does not conform to a standard NACA airfoil. I read, perhaps on Bruce Tharps website, that the airfoil on the 4* is a modified semi-symetrical shape where the bottom section of the foil from the main spar to the trailing edge was designed to be perfectly flat. This was done to facilitate the building of the wings on a flat surface without the need of tabs or other methods to hold the wing straight. This is one of the reasons that the 4* makes a good entry kit into kit building. Plus, the're a lot of fun to fly. One of the bigest problem with the 4* is the secondary effects of the rudder on pitch. Bruce Tharp, who originally designed the 4* has come out with a plane he markets directlly called the Venture, where he has made improvements to the design to help eliminate the problem. There may be a NACA that is close, but I have no idea what the number would be.

Scott