Thread: Stiff rudder
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Old April 15th 09, 12:09 AM posted to rec.aviation.soaring
Bob Kuykendall
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Default Stiff rudder

On Apr 14, 11:03*am, Steve Freeman wrote:

Short of going back to the factory, what do you suggest for a
replacement cable?


You'll almost certainly end up cutting one of the terminals off of the
cable in order to get it out of the tunnels.

I don't know what SZD's cable tunnels are like, but if they're not
continuous like mine (that is, the cable goes through discrete
fairleads and the like), you'll want to tape a tag line to the end of
the cable, and later use that tag line to draw the new cable through
the fairleads. If you're sure the tunnels are continuous, you maybe
can just push the new cable through the tunnels.

As you pull the old cable out, you'll want to monitor the friction
that you have to overcome to move the cable. If there's a spot where
it suddenly frees up, stop right there and mark the cable against some
reference point on the fuselage, say the end of the tunnel you're
pulling it out of. You can use that reference mark to lay the cable
against the side of the fuselage; the end of the cable will show the
location of whatever was causing the unusual friction. That might
reveal one of those pesky screws Jim was mentioning.

Once you have the cable in hand, you'll probably find that one end has
an expensive Kearney-swaged stainless steel terminal, and the other
end has a nicopress fitting with a loop around a thimble. The Kearney
swages require a very expensive tool, while the Nicopress fittings can
be applied locally. You can often get Nicopress fittings and tools
from your hardware store.

Your general strategy will probably be to order a length of 7x19 steel
cable with the appropriate Kearney-swaged terminal at one end, pull or
push the blind end through the tunnels, and then swage or have swaged
the Nicopress fitting at the blind end. The cable is probably 1/8" or
thereabouts, or the metric equivalent.

Of course, for a certificated glider you'll want to have this done by
an A&P mechanic, or do it under their direct supervision. For an
experimental glider, review the operating limitations that accompany
the Special Airworthiness Certificate.

Note that FAR §21.303(b)2 allows you to make (but not install) parts
for your own certificated aircraft within relatively narrow
boundaries. To be legal, you'll still have to convince your A&P that
your parts are safe to install. A Don Dodge article on page 20 in the
following edition of FAAviation News offers some guidance and a
cautionary tale regarding owner-produced parts:

http://www.faa.gov/news/aviation_new...ulyAug2002.pdf

Thanks, Bob K.
http://www.hpaircraft.com/hp-24