On 23/08/2011 01:57, Tuno wrote:
(Pardon my ignorance of the proper parts nomenclature ...)

There is a thumb wheel used to secure the tailplane (same for the wing
tips), and a blade screwdriver is used to tighten and loosen the wheel
after the fingers have done what they can.

Yesterday while derigging I made a half turn or so of the wheel before
I noticed the tailplane wasn't moving -- I had forgotten to remove the
gap tape. The tailplane came off properly after removing the gap tape,
but the wheel assembly came out too. It looks like it was secured in
the fin via an "O" ring or "C" clasp. I searched thoroughly for
something that might have popped off but could not find anything.

Does anyone know where I can find a replacement for this missing
piece?

Advance thanks

ted/2N7O

I's a standard (metric) circlip. Most auto parts places will have a
selection.

The circlip lets go if the nut is unscrewed while the tailplane can't
move (if, say, you haven't untaped it!). The nut pulls hard against the
circlip instead which pops off eventually. Each time the circlip lets
go, the sooner it will let go again as it slowly rounds off the edge of
the groove. By now, many LS-4 circlips let go if you blow hard!

The circlip is only to stop the nut getting lost when the tailplane is
off. It's not a serious safety issue.

Look around carefully, it's probably still on top of the fin somewhere.

GC