ORIGINAL: lfinney
maybe try some .5 ounce carbon veil on the inside of the sheeting, light and strong..., i think may you had very high frequency flutter
That's a thought. I will do something to stiffen it up front to back. If there was flutter I did not hear, I think it was in the wing and not the control surfaces. It must have been violent because one servo arm was broken off and the other one was missing the metal clevis. Everything fell into soft dirt and tall grass with no additional apparent damage.