Paul,
From your description I'm not quite sure where the failure is
located. If I remember correctly, the bell crank bearings are captured
between riveted plates and meant to rotate in one plane only. Any
deflection from that plane is handled by the rod end bearings bolted up
to the bell crank and protected by area washers to ensure the capture of the
rod ends.
Typically the bell rank bearing housing rivets are squeezed
rather than bucked - squeezed rivets can be more fragile than bucked
rivets in that they don't fill the hole as well.
Were I you, I would remove and inspect the bell crank for work hardened
and possibly sheared rivets since vibration is a common cause of fastener
failure. Perhaps even replace the rivets in both the left and right bell
cranks (assuming the bearings are not damaged). The method used by
Lancair is not unique to them - If you can find a better way, do it.
That is the beauty of the experimental, amateur built certification
category.
Scott Krueger
PS 1100 hours and no such problems. Uh, my annual condition
inspection is due this month and I will look at these bearing more
closely.
In a message dated 4/9/2009 6:49:57 A.M. Central Daylight Time,
marv@lancair.net writes:
Posted for PAUL HERSHORIN
<paulhershorin@bellsouth.net>:
I was returning on a
flight the other day and the stick started to vibrate--I
looked out at
the aileron and I could see the left aileron fluttering--I
landed
without any problem and started my investigation into the problem.
Upon opening up the bellcrank cover and moving the aileron the bellcrank
was
pushing up and down when moving the aileron and holding the
stick stationery. The bearing was twisting---my
question is how have other
individuals corrected this problem--the way
it is designed is an accident
waiting to happen.
Paul
Hershorin
360--471LA
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