Is this a common occurrence? I had problems on my Sig Kadet and now with my Avistar using the same engine, OS 40 with a 10 x 6 prop. I went from a Master Screw to the Top Flite Power Point wooden props. I have been told to go to APC since it is a better prop. I really tighten the nut down to where I think I am crushing the prop. Should I use lock nuts or Lock Tite or is this just a maintenance thing?

I had succeeded in starting the brand new engine at home all by myself. Then the first time I ever went to the field to fly, some guys were kind enough to help me get started in this great hobby. The prop came off and hit me in the chin, requiring five stitches, what a bleeder.