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REFLECTOR: front control bearing



Simon and friends,

The front bearing, its attachment and it's bracket was designed by Dan.
This came with the company the Swings purchased and has never failed,
under normal conditions, in almost 14 years now.  It has seemed wise
that if it is not broken don't fix it.  This has now changed.

I had trouble with this system once before and reported the incident
here on the reflector.  I did not know that the elevators had been
painted trailing edge down with three heavy coats of paint.  When the
aircraft was flown with the engine at the harmonic frequency of the
airframe and at a speed that off loaded the the elevator, extreme
elevator flutter was encountered.  Pulling back to 80 knots did not stop
it but abrupt forward pressure on the stick did instantly.  The landing
after I got around the pattern was a little sloppy which I figured was
nerves.  Close inspection of the aircraft proved otherwise.

The front bearing bracket was starting to rip out of the fiberglass and
the bearing out of the bracket but the bearing was intact.

As the control system "breaks in" wear on the ends of the shaft is
common.  This has always been fixed with washers in the rear.  All new
aircraft have a break in period after which they require tightening and
fine tuning.

 It can be very difficult to diagnose and fix an airplane over the phone
that one did not build.  I suspect and speculate that your system was
built so snug that there was an abnormal load on this bearing from the
beginning.  This would make your problem very different than mine.

In either case, Simon, we are still here and I hope no one else has to
experience what we have.

 I don't mine the FAA observing our problems and welcome there
suggestions.  If we address these problems ourselves openly in this
forum (the reflector) I hope the FAA will respect our knowledge as we
respect theirs.  In this way we will not be restricted in anyway to
properly address this serious problem and they will be able to retain a
passive roll.
The FAA and NSTB have the same goal as us... safety.  They have many
burdens and limited resources.  As a group we have great resources and
good reason to thoroughly investigate and address this problem.

Alan Shaw