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
--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html