Excessive friction in the aiteron circuit in SZD-55

On Apr 20, 7:10 am, Paul B wrote:
Hi

I have recently acquired SZD-55. The glider was manufactured in 1996
and has some 450 hrs. As far as I can tell the glider was maintained
very well by German workshop. Whilst I was aware that the 55 has quite
a heavy stick, I have only flown one other, this one seems to require
quite a force to move the stick whilst in flight. The friction force on
the ground is negligible. Whilst I found the glider great to fly,
responsive etc., the force required to move the stick becomes tiring
after a while. I also find that I tend to "overshoot" small
corrections, static friction requiring more force to overcome compared
to sliding friction. Has anyone had similar experience and if so how
could it be overcome.

Also I have noticed that when the stick is at dead centre, both ailerons
are deflected down by about 3mm (1/8").

Any help appreciated.

cheers

Paul

Hi Paul, I am anew SZD-59 owner and it also has a lot of friction in
the aileron circuit, but this is a known quality in the 59 not a
defect. The 59's ailerons are very heavy due to control circuit
friction, with no load, and naturally get much MUCH stiffer with
increasing airspeed. It is an acro ship though, and it could have been
intentional to reduce over-stressing tendencies, but it seems rather
extreme when actually experienced. I have little 55 experience, but it
would not be the first Polish ship with heavy ailerons if it turns out
to be a normal condition, (as opposed to damaged bearings and such) so
I am curious as to the answers and solutions, short of redesigning
major components. If it's as simple as a combo of strategic felt/uhmw/
teflon/etc then I'm all for it.

About the aileron droop, most ships have some sort of dip like that
while the ailerons are unloaded, but as soon as they are
aerodynamically loaded they should (assuming this adjustment is
correct) be in perfect cord with the rest of the wing when held
neutral. many people have tried to "fix" their sagging ailerons, much
to the detriment of the ship's performance, and is most likely a
calculated/built in feature. That said however, always get somebody
smarter than you (definitely smarter than me ) to look at anything in
doubt. Polish repair/maintenance manuals are usually pretty specific
on such matters as well for that matter...

Paul Hanson