From: "Brian & Susan DeFord" <deford@deford.com>
Subject: COZY: Left roll - update!
Date: Tue, 12 Nov 2002 19:06:32 -0700

All,

Just had to report to the group that I have corrected my plane's tendency to
roll left. After pleading for assistance a month ago, one of the suggestions
from a couple of you was to check the aileron shape. Sure enough, when I
checked the right aileron is was flat on both surfaces, but the left aileron
had a concave (cupped) lower surface and a convex (bowed) upper surface. The
curves were no more than 1/8" out of flat, but definitely made a difference.
Unfortunately I have spent the last month rebuilding the left aileron to
make it flat. I finally got it finished last week and had an opportunity to
fly it today for the first time. What a difference! I still had the wings
shimmed from the last flight to compensate for the roll so I expected to
have a right roll if the aileron was indeed the problem. As soon as the
plane was airborn she wanted to roll right! I didn't fly long (15-20
minutes), just long enough to get to altitude and fly straight and level for
a few minutes.

Now it makes perfect sense. The left aileron was acting like an airfoil of
its own and lifting. This upward deflection caused the left wing to drop, no
matter what wing shimming I did to correct it.

I'm resetting my wings to have no shims for the next flight and hopefully
will not have a roll in either direction. Thanks to the group for the
suggestions, once again proving the invaluable service this group provides!

Regards,
Brian DeFord, Cozy MK-IV N309BD