Message-ID: <004301c1da5d$5540ac40$66d1ea0c@attbi.com>
From: "Larry Graves" <larry@aircraftersllc.com>
To: <lancair.list@olsusa.com>
References: <000701c1da40$0d7de0c0$54f11942@gt.rr.com>
Subject: Re: Trim tab counter balance
Date: Tue, 2 Apr 2002 07:44:53 -0800
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>     How come trim tabs don't have to be counter balanced? 


Greg,

This is a woefully simplistic answer, but:

Everything has one or more frequencies called a resonance at which it will
happily start to cycle back and forth when supplied with energy (such as
from a slipstream).

That's why it's important to keep all your linkages as tight as is
practical - to reduce play and curb the tendency of a trim tab or flight
control surface to flutter. Trim tabs or flight controls that are "sloppy"
or improperly counterweighted are asking for trouble.

Smaller lighter objects have higher resonance frequencies, while larger
heavier objects have lower resonance frequencies. Chances are that a
fluttering trim tab, while a problem, won't cause the large flight control
to which it's attached to flutter.

Best Regards,

Larry Graves
AirCrafters Builder Education Center
Construction, Maintenance & Repair
140 Aviation Way, Watsonville, CA
831-722-9141
www.AirCraftersLLC.com

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