From: CHRISTOPHER_ZAVATSON@udlp.com
Date: Tue, 3 Oct 2000 07:48:27 -0500
Message-ID: <00302D57.C21254@udlp.com>
Subject: Preventing Spinner Backup Plate Stress Fractures
To: Lancair.list@olsusa.com
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>

There exists a technical solution to this problem that unfortunately died an
economic death.  Lancair had designed a carbon back plate for the 320/360 but
never went to production with it because the cost was relatively high.  I only
got about 100 hours out of my first aluminum back plate eventhough the spinner
runs true and the front end is supported by a bulkhead.  I examined the back
plate under a macroscope and discovered that the cracking was much more
extensive than could be seen with the naked eye.  Based on a previous factory
recommendation I did not use the riveted back plate stiffeners, but instead used
AN970 washers.  Being in the right place at the right time, I was offered the
opportunity to test a prototype of the new carbon back plate.  Its construction
is similar to that used on the IVs.  It has been going strong for the last 400
hours.  While it is more costly than aluminum, it does eliminate cracking
problems completely.  I'm sure Lancair would consider putting this piece into
production if there is enough interest.
Chris Zavatson
L-360 std
N91CZ
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>