Message-Id: <3.0.3.32.19990314190824.00ac7410@olsusa.com>
Date: Sun, 14 Mar 1999 19:08:24 -0500
To: lancair.list@olsusa.com
From: Marvin Kaye <marvkaye@olsusa.com>
Subject: LC20 attaching the stub wing skins
Mime-Version: 1.0

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The time has come for me to attach the stub wing skins to my center
section.  The manual calls for performing this activity with the fuselage
inverted and levelled, and recommends the use of wing contour jigs and
wingtip rib jigs for providing the straight edge alignments of both the
leading and trailing edges.  While I can see the logic to this procedure
for a standard build kit where none of the wingskins or ribs are attached
to the spars, the fast build kit includes the basic subassembly of the
wingskins and ribs with the alignments for washout and linearity with the
stub wing all done by the factory, so it appears there may be a better way
to perform this subassembly with the fast build.

After going through this manual section a number of times I can see no
reason for performing this activity with all of the associated fooling
around and fixturing required of the standard build kit.  Both Kuz and I
think the appropriate approach is to level the fuselage upright (its
present condition), bolt up the spars to attach the outboard wing
sections after verifying the level line which already exists on the tip rib to
insure that the washout is proper, and fit the stub wing skins to match the
outboard wing sections as provided from the factory.

When we installed the belly pan according to the manual's instructions,
everything was aligned properly, and we have no reason to doubt that
everything will align properly once again with this reassembly.  With the
fuselage upright it will make the process of filling the voids between the
upper spar caps and the insides of the skins much easier, ditto for
trimming down the partial rib at BL35 to fit.  We can also capstrip both
the partial (BL35) ribs and the BL50 ribs for final assembly and eliminate
having to apply those bids through the gear door openings.  As for bonding
the bottom portion of the stub wing skin to the bottom main spar cap, it
should be easy enough to apply the bonding Hysol and clamp that entire area
with a long board lined with foam and jacked into position from the floor
(no clecos into the spar caps for sure!) to hold it in position while the
layups cure.

I'd be pleased to hear from any of you out there who have already installed
your stub wing skins on fast build kits to see if we're not missing
something with this approach.  It all seems like a reasonable plan to us,
but we haven't been down the path before so don't really know if we're not
overlooking a major stumbling block.  Please send your comments to the LML
so everyone can participate in the process... no need for private emails on
this one.

Thanks in advance.

    <Marv>