[ProfLooney]

I tend to disaggree with the RAF 15 making bad models. all my brit designs use them and the guys building and flying them say they fly great. also the guys at the UK DP use proper airfoils and lot of RAF 15 used there and they have great flyers. the nice thing on the 15 is it is a thicker airfoil than normal. If your having problems I dont think its the airfoil but the incidence used. With the airfoils being underchambered and the "Hump" on the nose of say a RAF 15 you need to use the right incidences to get the airflow properly over them so they can use their job. a 2 to 3 deg incidence seems to work really good with these airfoils.