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Date: Thu, 01 Apr 2010 06:26:27 -0400
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Subject: [LML] Legacy maintenance idea
From: bob mackey <n103md@yahoo.com>
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> While working on my Legacy kit it occurred to me that once it's flying inspection
> and maintenance of the main gear would be so much easier if the stub wing skin
> could be removed.  I attached a hinge to the leading edge so that the skin could be
> opened as shown in the picture.  Now I'm trying to decide what sort of fasteners
> I should use on the trailing edge.  Any suggestions?

Inspections would be a little easier. Especially if you don't have a creeper
to roll under the aircraft.

But this will drastically reduce the torsional stiffness of the wing.
It might fly safely that way, but I would want to check the structural and
aeroelastic engineering to see what effects this major change would have.
I would expect that Greg Cole and Tim Ong sized the spars to take all
of the flight loads even without the skins - that's one way to allow for
poor construction technique in homebuilt aircraft. But intentionally
giving up the torsional stiffness of the wing is certainly not what they
had in mind.

IF (and that's a BIG IF) you had a bunch of really good screws and
nutplates to keep the rear of that door closed tight, how would you keep the
airflow smooth over the hingeline? It takes only a small bump or slot or
leakage to disrupt natural laminar flow on the upper forward surface of the
wing.

I strongly recommend discussing this build variation with the airframe
designers.

Greg Cole - Windward Aviation.
http://www.windward-performance.com/contact.php

Timothy Ong - Leading Edge Aircraft
http://www.leadingedgeaircraft.com/
timothy.ong@leadingedgeaircraft.com

Maybe Lancair has someone on the staff that can give an honest
engineering assessment. Or maybe they can only give the lawyer-approved
party line.


-bob