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Date: Thu, 22 Mar 2007 17:31:49 -0400
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From: "Dan Schaefer" <dfs155@adelphia.net>
Subject:  [LML] Re: Aileron Flutter
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Randy Stuart wrote:

"I've installed four small ribs made from 4 bid on each aileron."

Randy, I hope you've put some small drain holes in those ribs at the lowest 
spot. If not, water can collect in the counterbalances - not a good thing!

Having watched a number of wind tunnel flutter tests of aerodynamic surfaces 
and how quickly flutter onset can tear them off, I'd say you need to 
persevere until your ailerons are rock steady in any flight regime. Besides 
adding the counterbalance ribs, the suggestion (by someone on the list) to 
rig the ailerons slightly off-trail, to pre-load the control linkages, is 
also a good idea.

On my early 235, I did both and have never experienced the slightest aileron 
"buzz" (or anything related) even when I carefully explored the entire 
flight envelope - plus 10% - during flight test. Another thing I did was to 
cherry pick all the bolts and rod-ends in the flight control system for 
minimum clearance. Because AN hardware is manufacured with some tolerances, 
picking bolts with diameters on the high side and rod-ends with bores on the 
low side (even though only maybe half a thousandth or less) resulted in very 
minmal control system slop. Kinda tedious, but in my opinion, worth the 
bother.

Fly safe!

Dan Schaefer
Early LNC2 N235SP