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ACRO E-mail Archive Thread: [IAC-L:729] A very late THANK YOU to IAC list

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ACRO E-mail Archive Thread: [IAC-L:729] A very late THANK YOU to IAC list


Thread: [IAC-L:729] A very late THANK YOU to IAC list

Message: [IAC-L:729] A very late THANK YOU to IAC list

Follow-Up To: ACRO Email list (for List Members only)

From: N1BZRich at

Date: Tue, 19 Aug 1997 14:01:30 UTC


      Quite a while ago I asked our IAC list for help in solving a magnetic
compass problem that had recently developed on my Pitts S1S that I have been
flying for aver 20 years.  (I should have answered sooner, but other
commitments and Oshkosh have kept me busy.)  The compass had been very
accurate and had served me quite well as the only "navigation instrument" on
several long (coast to coast) X-country flights.  The problem had developed
after an extensive annual that included pulling the engine for the Lycoming
oil pump AD, replacing all fuel and oil hoses, replacing Lord mounts, etc.  
     At any rate, the problem is now solved, and I would like to say thanks
to the following people that responded with suggestions:  Fred Abramson,
Dennis Yugo, Luca Salvadori, Drew Lundgren, Eric Rood, John Collier, Dick,
Bert Berrong, Derek, Guido, Jeff Lo, and Hal Hitchcock. 
     Suggestions ranged from "Welcome to the club, you will never solve this
problem" to the correct answer  which came from Dennis Yugo.  Dennis
correctly suggested that the problem was caused by the starter not being
properly grounded to the airframe and the Tachometer cable was acting as the
ground from the engine to the airframe and becoming magnetized.  Well sure
enough, I had repainted the engine mount at the annual and had not removed
enough paint when attaching the ground strap from the engine to the mount.
 After doing that and de-magnetizing the tachometer cable, the compass was
back to normal.  Success! 

Thanks, Dennis!  

Buz Rich
IAC # 2794


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