Mailing List lml@lancaironline.net Message #40400
From: Zavatson, Christopher J (US SSA) <Christopher.Zavatson@baesystems.com>
Sender: <marv@lancaironline.net>
Subject: MKII elevator hinges
Date: Thu, 01 Mar 2007 14:13:45 -0500
To: <lml@lancaironline.net>
The recent discussion of elevator hinge play reminded me of a related issue on the MKII elevator.  The root cause of the wear issues in hinges for this particular location are the loads induced by the torsional input from the engine.  The spherical bearings in the MKII tail are not immune from this abuse.  The original bearings are of the low end COM series.  After some 7 years I noticed that slight vertical movement outboard on the elevator was now possible.  The clunk-clunk sound of metal on metal was quite distinct.  I ended up replacing these bearing with Aurora Precision Series bearings (LHA 4).  The static load rating is more than double the COM series.  Not that we ever expect to be pulling on the bearing with 10,000 lb, for us this translates into greater resistance to the development of play due to the higher strength materials used.  Shortly after this switch-out Lancair began offering replacement bearings with a PTFE liner.
I also switched out the rod end bearings in the main gear over center link in about '98 @ 200 hours for similar reasons.  The original bearings had a bronze race, the replacement is alloy steel - again with twice the load rating (Aurora AM series).
 
Chris Zavatson
N91CZ
360std
    
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