Mailing List lml@lancaironline.net Message #52687
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Strength vs. stiffness
Date: Wed, 19 Aug 2009 13:01:26 -0400
To: <lml@lancaironline.net>
Charles,
 
It is a lot easier if you have not closed the vertical stab yet.  In the area of the strake that rises to meet the vertical, one could carve foam to fill the rise up to the bulkhead/forward-spar, flox it into the installed half of the vertical stab, glass the foam to the tail cone (and bulkhead) and use flox to fit the final vertical skin as directed by the manual for pre closing. Then bond the skin on to the ribs and the new structure added in the strake area. 
 
Note that Legacies ordered for racing had extra layers of carbon cloth wrapping the area somewhat forward of the tail cone and on up the vertical stab for strength and stiffening of the tail crucfix. 
 
If you have closed the vertical stab, you will need a thin person with very long arms or a small obedient child to install the plug and cover it with glass.  Send inquires on technique to Mark Ravinski.
 
Remember that stiffening one area transfers applied forces to another.  Also, If the structure is subjected to vibration (uh, what part of an airplane isn't?) its response to that vibration will change if part of the structure is stiffened.
 
I installed Mark's fix.  The 2" barely-visible hairline crack in the paint along the mid-strake joining seam has not gotten larger.  I believe I have seen increased effects of vibration in the loosening (wearing) of the right outboard elevator hinge.  I have the small tail.
 
Scott Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)
 
In a message dated 8/19/2009 5:30:12 A.M. Central Daylight Time, Csims440787973@aol.com writes:
If you have the pictures available, I would like to see them.  I am building and have heard various solutions to the problem of the cracks round the tail.  I would like to do this right if other builders have already solved the problem, I would like to follow the correct path.
 
Charles Sims
360 builder
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