I'm with Red on this as well. The SD airfoils work well and I have also used the six digit NACA 64a 21001 the four digit 1412 and the five digit 23012. But you need to land fast as these have will tip stall The 1412 turns tighter, but when you pull that hard it bleeds off speed. These work well with 2 degrees of wing incidence and 1 degree of stab incidence using an 11 or 12 percent thick tail surfaces.