From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] LNC2 Friction in Roll Control
To: lml
Date: Mon, 02 Dec 2002 22:03:45 -0500
Message-ID: <web-1893223@logan.com>
In-Reply-To: <003801c29a6a$3561adc0$6601a8c0@cruzio.com>
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Posted for "Dave Saylor" <Dave@AirCraftersLLC.com>:

Lee,

Your instincts are good in treating this pretty seriously.  Control friction 
can be a sign off really bad problems.  I wouldn't fly until you figure out 
what's wrong.

It sounds like you may have a bad rod end or bearing.  Try simulating the 
flight loads by pushing up on both ailerons at the same time from the neutral 
position.  It may take three of you.  When you move the stick, listen for any 
strange noises and otherwise see if you can duplicate the friction.  It might 
mean a pretty time consuming search.  Rod ends are really good at transmitting 
motion when they're in good condition, but they can get very draggy when they 
start to fail.

Also, check to make sure there is no sign of interference at the aileron 
leading edge, top and bottom.  It's common to try to close the gap as much as 
possible, but zero clearance too close!

You should swing the gear in the hangar and make sure there's not any 
interference from a hose, cylinder, or some other component.

The scariest aileron binding I've seen involved an S-Tec servo in the wing of 
a 320.  This all happened on the ground, but I shudder to think about it 
locking up in flight.  The builder had neglected to install the required 
stops, thereby allowing the motor to rotate endlessly as it searched for its 
commanded heading.  As it hunted the stick would slowly cycle left to right 
over and over.  The problem came when the power was shut off with the stick at 
full deflection.  Then, with the servo input rod at its 3 or 9 o'clock 
position, parallel to the aileron pushrod, it would very effectively lock the 
aileron control full left or right.  I imagined a situation where the AP 
started hunting for some reason, and as the plane quickly rolled farther and 
farther, the pilot shut off the autopilot or master switch to make it stop. 
  That would lock it in place for good.  We installed the correct stop bolt 
per 
a Glasair installation manual which solved the problem.

Anyway, your problem sounds more like friction and not full lockup, but it 
might not hurt to check for the stops.  Let us know what you find.

Good Luck,

Dave Saylor
AirCrafters LLC
www.AirCraftersLLC.com
831-722-9141


>>>>One real noticeable 
difference, however, is in the freedom of movement of the stick in roll while 
in flight.<<<