From: Epijk@aol.com
Message-ID: <43.1627097b.284d1147@aol.com>
Date: Mon, 4 Jun 2001 12:28:55 EDT
Subject: Re: LNC2 Elevators fast build
To: alphadog@nii.net, lancair.list@olsusa.com
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RE the concave elevators: I would recommend against filling the concavity, 
simply because it will make the mass balancing of those surfaces more 
difficult, as well as increasing the mass moment of inertia (MMOI) of the 
elevator system: more weight on the skins, relatively far from the hinge 
point, and the additional weight in the counterbalances to compensate. I 
don't have the numbers for that airframe, but elevator flutter is a real 
concern in high speed aircraft, and it is effected by (among other things) 
control system stiffness and surface MMOI.

Further, the elevator concavity could noticeable affect the control response 
and linearity of the elevator system, potentially leading to premature 
separation at high deflections. That might be made worse by the asymmetry of 
the concavity.

My recommendation would be to convince Lancair to sell you the components 
necessary to build a new set of elevators, and take the current ones and 
mount them over your fireplace as a reminder: "There's never time to do it 
right, but there's always time to DO IT OVER!
Jack Kane
EPI, Inc.
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LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.
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