Peter
I second Michael's rudder statement. I have a Grob 103 C Twen Acro III
and the rib that is glued to the vertical skin by the upper hinge came
unglued. You can check this by putting pressure on the right side of
the rudder at the upper hinge point and see if the vertical fin moves.
The glider had five hours on it at the time.

Ken (KP)

On Jan 12, 12:30*am, "Michael Huber" wrote:
Peter,

check the rudder hinges and the ribs that holds the hinges.
Michael