On Sep 15, 8:09*am, Kenneth Kilbourne
wrote:
What causes the buckling/oil canning on the bottom of the ailerons and the
elevator on Grobs? I have looked at 6 ships and they all have the same
problem.

That's just the way lightly-built non-sandwich composite skins age.

What's the fix?

I don't think it has shown itself to be a real problem in most cases.
JJ will probably correct me if I'm wrong, but in the absence of other
damage, they are probably structurally sound. And on these two-
seaters, the performance hit is negligible. So the best fix is
probably just to not look at them.

Thanks, Bob K.