Thanks guys for your comments. Well... some say it can be done , some say it can't. I know a lot of people including myself in order to stay in KE tilt the wings from vertical few degrees one or the other way and with a little elevator input you can control altitude, so you don't fall out of it. It's a little cheat but it works well. I believe you should be able to do that with this little beast. The only problem is that some planes need more input than others (depending on CG, power plant, shape and amount of rudder deflection available). The planes that don't KE well would probably require tilt that nears 45 degrees but would you still call it Knife Edge?