Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Wed, 22 Jan 2003 15:38:54 -0500
Message-ID: <redirect-1995165@logan.com>
Reply-To: "Dan Schaefer" <dfs155@earthlink.net>
From: "Dan Schaefer" <dfs155@earthlink.net>
Subject:  LNC2 Nose gear pivot tab hole elongation
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Scott, et al.

The part you're talking about is similar in function to the anchored end of
the over-center links on the main gear (the one that has the rod end bearing
and attaches to the bolt-up on the gear leg).

Back in '93, just days before first flight on my LNC2, a hangar mate had one
of his fail on take-off and his airplane was messed up pretty bad. The
failure mode was due to poor design (sorry Lance!) where a AN490 Threaded
Rod End (male) had it's plain end inserted into a matching hole bored in end
of the o/c aluminum link and affixed with structural adhesive and a 3/16
thru-bolt. (This deficiency has since been addressed by the factory). At the
time (and looking at the resulting damage to the "incident" Lancair) I
redesigned the part to eliminate the failure mode and had a local machinist
make some up for me. I took him the original part, he basically copied it
for dimensions and then included my changes. He charged about $95 per pair
when I had a dozen sets made.

The redesign changed the material to steel - the machinist suggested a high
strength alloy that was also tough - and used a threaded hole (NF - Class 2,
if I remember) in which a length of stainless All-thread was inserted
extending to the same length as the AN490. The rod-end was then installed on
the All-thread shaft to the same dimensions as the AN490 and reinstalled on
the airplane.

The reason for relating this saga is to suggest that the same thing could
easily be done to the nose gear o/c link part to get the rod-end bearing
where you suggest to eliminate the wear point. It's unlikely that a rod-end
ball will be exactly a snug fit between the tabs but some judicious shimming
with washers would probably do the trick, allowing the ball to be firmly
captured by a bolt.

Cheers,

Dan Schaefer