Mailing List lml@lancaironline.net Message #3582
From: Rumburg, William <wrumburg@cdicorp.com>
Subject: RE: LNC2 SB050-0999
Date: Thu, 14 Oct 1999 09:24:20 -0400
To: 'Angier M. Ames' <alphadog@nii.net>, <lancair.list@olsusa.com>
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Hello Sonic BOOM....

What is so unusual about the construction of your plane that removal
of the
gear requires removal of the wings first??? This is certainly not
the case
with mine.

Mystified as always...Angier Ames

Well, great...just what I wanted...the spotlight...

The problem is access for a wrench into the blind area on the front
side of the main gear mounting plate in order to remove the four bracket
attach bolts.
I installed all four nuts and washers on the aft side of the main
gear mounting bracket (i.e. inside the gear well), which actually makes
bracket removal a little easier because you don't have to maneuver the nuts
into the blind area (on the front side of the mounting plate).
I removed and reinstalled the main gear several times during
construction and two or three times since. In each of those instances, the
wings also happened to be removed so there was access for a wrench into the
area on the front side of the mounting plate (through the aileron pushrod
and fuel line holes in the BL 50 rib). Removal of the bracket is then no
problem.
The problem as I see it, is maneuvering a wrench into the blind area
on the front side of the mounting plate with the wings still installed. I
suppose you could take a standard box or open end wrench and cut it to
shorten the length, so as to make that possible.
No one likes the thought of removing the wings. For me, the worst
part is lockwiring the wing attach bolts. I've done that a few times, so I'm
getting better and faster, but I have a mental block toward it. Of course,
draining the wings of fuel, removing ailerons, flaps, aft attach bolts,
wiring, etc. etc etc. is no picnic either.
I still maintain that a full-width secondary attach point is far
preferable to this "fix". Breaking out an existing attach block is no picnic
either, but if you have to go in and do it, you may as well do it right.
For this potential problem, one could ALMOST say "If it ain't broke,
don't fix it", except that there may now be at least one pilot out there
with a partially collapsed main gear and a lot worse damage to repair as a
result, i.e. broken main gear primary (as well as secondary) attach block,
wing damage (and maybe an extensively damaged airplane-and people-if a main
gear partially collapses on a landing with severe side loads)
  It's also tempting to say "Well, I'll keep a close eye on it and
make a repair IF IT STARTS TO BREAK". True, it may never break. The left
side attack point on my 320 has not shown any indication of failure. You may
have ample warning before the attach point fails completely. You also may
not, with results as described above.
  It's easy to see Lancair's reason for making it mandatory. It
must have taken many reported failures and maybe a collapsed main gear to
force them to issue the SB in the first place.
  This rework is useless, unless it's done WELL. To do so, you have
to remove the main gear forward mounting bracket, which necessitates a lot
of disassembly for a completed aircraft.
Bill Rumburg
N403WR  (Sonic bOOm)

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