Sender: "Marvin Kaye" <marv@lancaironline.net>
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Date: Mon, 03 Jan 2005 23:40:14 -0500
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Subject: RE: Legacy Rudder Bellcrank
Thread-Topic: lml Digest #1079
Thread-Index: AcTxg8la3eWju/acQeWRtXehxtxLwwAkJifw
From: "Halle, John" <JJHALLE@stoel.com>

Two of us have recently replaced the rudder bellcrank and bushing in our =
Legacies.  The problem first surfaced when it seemed like someone was =
kicking on the rudder pedals Carl Lewis' Legacy on landing rollout.  On =
inspection, the rudder could be moved back and forth about three inches =
without moving the rudder pedals and the bellcrank was tilting forward =
and aft as the rudder was moved back and forth.  When we got the =
bellcrank out, the bushing was very loose in the hole.  It wouldn't =
quite fall out but it could be pushed out without any effort and it =
could be rotated to about 15 degrees of tilt in any direction while =
still inside the hole.  Carl's Legacy has about 100 hrs. of flight time. =
 When I got back to base, I inspected my airplane (in which I had not =
experienced any unusual rudder action) and discovered the same problem.  =
Mine was not as bad as Carl's even though it has about 400 hrs.  The =
rudder moved back and forth about one inch and the bellcrank tilted =
less.  Sure enough, the bushing was also quite loose in my bellcrank but =
not as loose as Carl's.  After reinstallation, the rudder still has =
about 1 inch of slop so that seems to be normal.

The replacement parts had a very tight bushing fit, requiring =
installation with a vice.  Neither Carl nor I, nor Leighton Mangels, who =
helped with building both airplanes, remembers doing that with the =
original parts so it is possible that there is a spec change.  We think =
a tight fit is essential since any movement of the bushing against the =
bellcrank will eventually gouge out the hole.  It is also possible that =
over-tightening the bolt that goes through the bushing could pinch down =
on the bushing and cause it to rotate against the bellcrank (instead of =
the bellcrank and bushing rotating against the bolt as designed.)

The replacement was a challenge in a number of ways.  Space back where =
the bellcrank is installed is severely limited and for both of us was =
more limited than when we made the original installation because of =
avionics installations and the elevator pushrod, which both of us =
ultimately removed.  Removal of the bellcrank assembly went fairly =
smoothly but only because during construction we had made an access =
panel that allowed us to unhook the rudder pushrod at the rudder end and =
pull the entire assembly forward.  Getting to the bellcrank bolts was =
bad enough; I don't want to think about how we would have unhooked and =
reattached the rudder pushrod at the bellcrank end.

Reinstallation was quite a bit trickier.  The rudder cables tend to pull =
forward once the bellcrank is unbolted and need to be pulled back.  The =
composite material to which the bolt nutplates are attached was not =
drilled out wider than the bolt diameter, which required us to unscrew =
the bolt using a ratchet wrench all the way through the composite.  On =
the reinstall, we could not get any of my bolts (there are three) to =
thread by hand and ultimately used a 90 degree angle drill with a socket =
attachment to get enough pressure and speed on the bolt to make it work. =
 Carl got the front and back bolts in ok but seems to have messed up the =
center nutplate a bit on removal.  A tap fixed the problem but only =
after several unpleasant hours wedged in the tail.

If you are still building, here are some suggestions:

=B7	Check to make sure the bushing fits tightly into the bellcrank.  If =
you can just push it in or out, it is not tight   enough.    =20
=B7	Put some grease on the AN 4 bolt (that goes thru the bushing).  =
Couldn't hurt.
=B7	Make sure you don't overtighten the bolt.  Ratchet it all the way in =
and back off a hair.
=B7	Make an access panel in the rudder to access the pushrod.
=B7	Hog out the composite above the nutplates so the bolts don't hang up =
on it.
=B7	When you are installing all your neat EFIS stuff, think about how =
you will get past it if you ever need to get to the bellcrank.

If you are already flying and the rudder seems more than usually floppy, =
check out your bellcrank.  If it tilts forward and aft as the rudder is =
moved, the bushing is loose and will only get worse.  If you have the =
problem, find a 98 lb. A&P with really long arms and wish him lots of =
luck.  Don't forget to put something under the tail.

If you want more information, please contact me or Carl; or, better =
still, contact Leighton (leighton@teleport.com) who knows more about it =
than either of us.