From: Sky2high@aol.com
Message-ID: <9bc6cfbd.24908c14@aol.com>
Date: Wed, 9 Jun 1999 23:33:40 EDT
Subject: LNC2 Nose Gear Strut Review
To: lancair.list@olsusa.com
CC: Lynda@lancair.net
Mime-Version: 1.0

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Of course, any good Lancair discussion requires a story with a moral -- This 
is no exception.  Pull your chairs near to the wood stove and listen up!

I started building in 1989 and therefore, received an early version of the 
ESCO strut.  Serial No. 30 to be exact.  Thru the many years of building, I 
religiously executed all the service bulletins -- From memory (old people 
only remember history), I applied Locktite to the screw-on flange and later, 
sent in my strut for a more complex internal service which resulted in it 
becoming serial number 30A.

Finally finishing N92EX (1996, I am a sloooow builder), I recently flew to 
S&F and mentioned theoil oozing from under the flange.  Lancair expertise 
indicated it was an internal leak, possibly serious, and I should return the 
strut for service.  Upon returning home (nice flight, red carpet in Gadsden 
AL) I thought I would send in the strut and also request the "centering" 
upgrade since I had the usual scrape marks on the door caused by the 
occasional, slightly off-center, retraction of the nose gear.  

The strut was returned within a week with the centering upgrade complete, 
including a beefier ram and a much beefier flange with a locking collar.  
Conversation with Lancair indicated that the leak, resulting in low oil, may 
have lead to the apparent trashing of the internal mechanism -- I was lucky 
to have sent in the strut before a complete failure had occurred.  Good. 
However, the new collar interfered with the Lancair towbar attachment, but it 
was suggested that the pin/bracket be placed below the fork when everything 
was bolted up.

So Far, So Good!

After a few flights, I found oil on the nose wheel center tread.  Further 
investigation revealed a leak from the ram seal and the strut had sunk 1/2 
inch lower.  Conversation with the strut rebuilder indicated that he had done 
50 with no leak, but the seal installation, requiring the seal be streched 
over some parts, was difficult and I should return the strut to have the 
problem fixed.  I did just that.

Today, (Yes, Mid April to Mid June - No fun Lancair flying -- I couldn't find 
anybody to hold up the nose while I taxied) I installed the "re-sealed" strut 
and noted that the collar (firmly fixed by a hex-head bolt) was quite loose.  
A call to Lancair Management (Quality Control?) concerning the danger of 
sending out struts in that condition resulted in a call back from the strut 
rebuilder with the following comment -- We send them back loose so that the 
builder can set the wheel to track straight and then tighten the flange 
lock...(Indeed, this is a two-piece affair with slotted holes in one part).  
"WELL!" I said, "I had no such information on the first install and I flew it 
a few times that way (It was snugged enough to not appear loose)."  The reply 
was "I should write up instructions on that".

Further thought had me consider that perhaps, possibly, I should commit 
myself to the local loony bin.  

Consider the following:

First -- The self-centering mechanism only operates when the strut is fully 
extended (a pin entering an inverted v slot?) so that when the gear is 
retracted, the wheel is straight and will not bang its way into the well.

Second -- When the strut is compressed, there is a mechanism to dampen twist 
of the nose wheel, but no centering mechanism other than rolling in a 
straight line (definition of  unsteerable full castering nose wheel).

Third -- We all built our wheels to run straight and retract straight (as 
best we could).

Fourth -- It is a fact that the centering mechanism, when seated, allows 
about a degree or so slop in the wheel alignment.  The slotted holes allow 
several degrees of wheel movement. 

So, the directions should be that the flange is adjusted so that the wheel, 
when centered on extension, will retract into the well without hitting the 
door or the sides.

Flight will be tomorrow -- I will let you all know if it didn't work.

BTW - Moral --- trust no-one, including yourself.  Check everything twice.  
Everyone is out to get you.  Get other people to check your work, but don't 
trust them either.  Join my new group PEOPLE (Paranoia Explains Other 
People's Lost Empathy). Trust me.

Scott Krueger (I promise I'll go straight)
N92EX 


PS Jim Frantz - Possible 1 Sentence SDR -- LNC2 factory nose strut update may 
require phalange exploratory examination for loose flange.
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