Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Mon, 02 Sep 2002 19:38:53 -0400
Message-ID: <redirect-1720441@logan.com>
From: "Charles L. Keller" <clkeller@utahweb.com>
MIME-Version: 1.0
Subject: LNC2 TAILCONE TWIST
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>>>  Question What is the best way to make the h-stab horizontal? Cut
off the
high saddle or cut off the low saddle and extend the support???  <<<
    I am in the middle of mounting the horizontal stabilizer (HS) now
and have faced the same problem. I spent some time talking with Mark M.
at Lancair this weekend at the fly-in and he approved of what I've done
so far and made suggestions about the rest of the job.
    The left saddle on my fuselage was considerably higher than the
right. I placed the HS in place, checked incidence and level, then began
to file away at the left saddle and the fuselage bulkhead under the HS
main spar until I had the HS level and at the proper incidence. At this
point the HS was resting only on the right saddle and the bulkhead; the
left saddle had from1/4 to 1/2-inch clearance from the HS bottom skin. I
cut narrow pieces of foam to fill the gap and secured them in place with
micro to serve as outboard dams. Then built cardboard dams inboard and
filled with dry micro per the manual (p7-56). When cured, trimmed the
inboard edge of the micro, then went back to mounting the HS, checking
level and incidence and filing the top of the micro accordingly.
Sometimes it is hard to tell where the high spot is, so I put duct tape
on the HS lower skin where it mated with the micro and painted it with a
black marker pen. With the HS in place I could move it fore and aft
slightly, or rotate it a tiny bit, which would leave a black smudge on
the micro at the high spots. Took them off with file and sandpaper.
Repeated the process until the HS was level again and incidence within
limits. Must have had the HS on and off over a hundred times. This is as
far as I've gone, but I'll describe where I'm headed.
    The left side is left with a very small fillet radius, while the
right side has the whole fillet plus a vertical surface of micro. Mark
said he likes a small radius and thought the left side would be OK with
only minor applications of micro, but I choose to bond in a piece of
foam which can be sanded to a slightly larger radius. He thought that
would be fine. I'll fill the top of the foam with micro to extend the
surface of the saddle and apply the 3 BID per the manual. Then I'll trim
the right saddle to match the much narrower width of the left side and
grind away the original glass fillet and much of my micro to get a curve
matching the left side. After the HS is bonded in place I'll put a
layered 3 BID from the fuselage side, over the fillets and onto the HS
lower skin.
    I assume you've put in your vertical stabilizer spar first -- that
was another challenge with the twisted tailcone. Also do all your rudder
cable runs and whatever needs to be in the aft fuselage under the HS
before bonding the latter in place.
    Isn't this fun?
        Charles

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