Mailing List lml@lancaironline.net Message #64969
From: Clifford Scheel <candp_scheel@msn.com>
Sender: <marv@lancaironline.net>
Subject: Lancair ES-P cracks
Date: Sun, 17 Mar 2013 13:10:04 -0400
To: <lml@lancaironline.net>
After nearing completion of the repairs to my ES-P, I thought it prudent to pass on my experience.  A neighbor was visiting recently and noticed a fresh six foot long crack in the paint, down the right side of my plane, at the junction of the top and bottom of the fuselage.  The plane is two years old and has about 175 hours.  It is almost always flown above 16,000 feet, up to and including FL 280.
 
Upon inspection it was obvious that there was a week point where the top and bottom of the fuselage overlap, where there is no core for stiffening.  To my knowledge, Lancair has never supplied a construction manual for the ES-Ps, but rather given out the ES manual with supplements from the 4P book, but nothing for this joint.  After joining the top and bottom, and reading the requirement for one bid, two inches wide, over this joint, I concluded that was not sufficient for a pressurized plane, and applied two bids three inches wide over both the inside and outside.  Obviously still not enough.  Another neighbor (it's nice living in an airpark) dug out a page from a 4P manual and it showed a requirement for three bid, two inches wide.  After all of the paint and filler was removed, it was determined that the joint was sound, with no delamination's or structural failures yet, just to much flex.  Eventually this flex would have caused the joint to fail, and if at full pressurization, could have been catastrophic.
 
I  talked to a professional builder, and he said they always use carbon fiber for this part of the construction, which makes a lot of sense since the fuselage is made of carbon fiber.  I have put in three bid, six inch wide, carbon fiber over both inside and outside, for strength and stiffness.  This is in addition to the two bid, e-glass that was already there.  Since I have had to tear up the plane, I decided to do both sides to be sure I don't have to do this repair again.
 
The point I am trying to make is, if you own an ES-P, you need to keep a close eye on this joint to see if yours is strong enough.  My plane has at least 1/8 inch of micro fairing over the outside, and that may have contributed to the paint cracking since micro doesn't flex very well.
 
Just a friendly warning!!!
 
Cliff Scheel
N272CS
Dry Creek Airpark
 
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