Thanks, I appreciate the info. I know on ful scale they are critical and used for the exact reason you posted.

I had a Carf Hawk tip stall on me this weekend, no warning what so ever ( you usually do feel a buffet, even in rc ), the plane went knife edge and was able to catch but the nose dropped off fast.

Afterwards the builder brought me the fences that were'nt put on - I immediatley got that rotten gut feeling.