Message-ID: <003101bfb37f$8d2390c0$5bf5acce@default>
From: "Ian B. Crowe" <ian.crowe@sympatico.ca>
To: <pine@cpro.co.za>
Cc: "Marvin Kaye" <lancair.list@olsusa.com>
Subject: Removeable seat back
Date: Mon, 1 May 2000 11:11:37 -0400
Organization: Corvi Trade Consultants Inc
Mime-Version: 1.0

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I too am in the throes of putting in a removeable seat back and the
integrity of the seat back, as a bulkhead, has to be in question even if you
installed it as per the manual.  This is due to the fact that when you
install the forward opening canopy the latch locking system operating handle
requires a long 5/16" to 3/8"wide slot right in the middle of the back seat
panel.  This effectively removes 75% of the material and leaves you only a
small portion at the top.  You then glass on the top horiziontal portion to
the seat back which gives it strength.  In addition the back butts on to the
elevator tunnel sides.

I wanted my seat back to be removeable so I have spliced in hard points in
the seat back at the console sides area and am fastening the console sides
to the seat back via pieces of 11/4" angle and #8 screws.  The top
horizontal portion of the seat back is also a piece of 11/4" angle screwed
to the seat back top.  The seat back also has a hard point in it from one
end to the other to carry the #8 screws which hold the seat back to the
angle.

I should add that on the fuselage sides I had preformed some 11/2" Al. angle
which I floxed and glassed to the fuselage sides.  It was a little tricky to
get the right curvature but it worked out.  The seat back rests on the angle
and is held by #8 screws.  I figure that the whole assembly would be at
least as strong as the method shown in the manual.

Having said all that there was very early on in the Lancair list an item
from someone who had put removeable panels in the seat backs.  Have a look
for it Pine it might help.

If you have a tame mechanical or structural engineer around he would be able
to advise you as to the most effective way to maintain the structural
integrity, which is doubtful at best, IMHO.

Kind regards

Ian

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