Mailing List lml@lancaironline.net Message #61272
From: <rwolf99@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] LNC2 - Harminization between pitch and roll
Date: Tue, 06 Mar 2012 07:39:36 -0500
To: <lml@lancaironline.net>
Bill is right.  Handling qualities are all about stick FORCE. Stick displacement is not the issue, as long as you have enough room to push the stick as far as you need.
 
Moving a pivot point in the linkage closer to the axis of rotation will increase stick force, and also reduce stick travel, for a given elevator displacement (i.e. for a given aircraft response).  The Lancair 320 accomplished this in the 1990's by changing the elevator weldment (the bracket bolted to the elevator that the aft pushrod attaches to). The new weldment moved the attach point 1 inch closer to the axis of rotation (just as Bill said).  But fear not, the earlier guys just drilled an extra hole in their weldment and ignored the original hole.  In principle you can do this anywhere in the system, but it seems to be easiest to implement out at the tail.
 
I have both weldments in my hangar.  The old one is kinda gold, almost as though it were cadmium plated like an AN bolt.  The new one is silver, almost as though it were chrome plated.  But the bottom line is the number of inches away from the pivot point.  If I recall correctly the new one is 2 point something inches away and the old one is 3 point something inches.  (Big help, huh?)  I would have to go to the hangar to check.
 
This mod is fairly benign. 
 
Keeping the CG forward helps, too, but is harder to accomplish.  Moving a battery from behind the seat to the front of the passenger footwell might be worth investigating if you don't have rudder pedals there.
 
- Rob Wolf
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