From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: Need IVP Horizontal Stab advice
To: lml
Date: Mon, 28 Mar 2005 12:07:16 -0500
Message-ID: <web-827424@logan.com>
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References: <001f01c5335d$bef46530$7486e718@D9T70F41>
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Posted for "Tom Sullivan" <toms1@chartermi.net>:

    I have gotten as far as I can go efficiently with my plane on the
rotisserie pending my turbine belly tank arrival.  It looks like I would be
struggling to keep busy without finishing my intentionally delayed tail
feathers (makes rolling it over so much easier).  So I spent a good day
dropping, jigging, leveling and securing the fuselage for that work.  I had to
heat and straighten the lower fuselage at the rudder area for true plumb.  In
doing that I also had to perform a flox release on the mount area for the
stab, since it was no longer a good fit.  I have a 1999 vintage fast build
with factory performed wing mating, and can't remember at this time what I
found when rechecking for level on the wings back a few years ago when I did
the winglets.  I know it was really close or right on, just not sure.
    Now the fuselage is very secure and level in a location that will not 
allow
wing installation.  The manual shows installing the stab before the wings are
on, so it would seem installing per manual (with everything leveled to the
factory spec's) would be acceptable.  I am just concerned that if the wings
were off a tenth of a degree or something, the stab would be level with the
fuselage, hence not true with the wings.  Am I splitting hairs here?  It would
sure be easier to just install the stab.
  
    The second question, the manual show .6 degrees incidence, I found in the
archives some builders going to .4 degrees.  I am at .5 with the flox release,
and could go up or down a tenth real easy.  With the turbine, is there a
better setting than the original .6 degrees?
  
  Thanks,
  
  Tom Sullivan
  Iron Mountain, MI


[I'll stick in my 2c, for what it's worth... generally I would prefer to have 
the wings affixed to the fuselage prior to fitting the horizontal stab.  This 
would guarantee that both the wing/fuselage and stab/fuselage placements 
matched.  With the wings attached you have a 30+ foot line with which to level 
the fuselage in the roll axis, as a fraction of a degree error across the 4 
feet of fuselage gets magnified almost 8 times out at the wingtips.  With the 
wings attached you level them from the tips and the fuselage then goes where 
it has to go.  Then you match the stab to the wings and everything is aligned 
properly.  Keep in mind that the wings and stab are the flying surfaces and 
the fuselage is pretty much "along for the ride" while it performs its 
function of being the common link between those two components.  Doing the 
stab with the wings on also insures that the visual relationship between those 
two components matches when the aircraft is viewed from the front or back. 
 For my way of thinking, accepting that the spar box (the interface between 
the wings and fuselage) is perfectly aligned across that 4 feet available for 
measurement (that then gets transferred to the spar mounting location) is a 
leap of faith I'd rather not take.  YMMV of course.  FWIW.        <Marv>    ]