Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Sun, 19 May 2002 21:40:31 -0400
Message-ID: <redirect-1242056@logan.com>
From: Sky2high@aol.com
Subject: Re: [LML] Re: The Flight of Two Madmen - Gear Electraulics!
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Larry,

You are right.  In this case, Arnie (like many others) wired his relay power 
thru a "Miscellaneous" breaker and cannot afford to pull it if he pulls the 
motor power breaker.  Since he had an irritating slow leak in his 
electraulics system, he would pull the only the motor breaker for great 
lengths of time on the ground during taxi, but this would only affect the 
"down" part of the system.  

It is possible that the failed pressure switch would keep the "up" relay 
engaged, but we all know when the pump is running in flight.  Perhaps he 
unknowingly had the motor breaker pulled during our 2.3 hour flight to OGD.

In any event, I have tried to get Lancair to alter their wiring diagram for 
years, but to no avail.  The safest way to wire your electraulic system is to 
wire the relay power breaker, fuse or inline fuse after the motor power 
breaker.  This way, when the motor breaker is pulled, all the power is taken 
off the complete system.  

An additional consideration is that the "pump running" indicator light is 
powered off the motor relay contacts.  A short in the indicator light circuit 
would be presenting 50 or 60 amps to a 20 or 22 gauge wire with no 
protection.  I can smell the wires burning now.  This circuit from both 
relays should be diode isolated and fused.  The Legacy circuit at least uses 
very small diodes (no fuse) and one would hope they would pop before the fire 
started.

Gentlemen, fix your electraulic system now!

Note: The term "Electraulic" used to describe our electric-hydraulic system 
is the invention of Tom Giddings.  I love it and the English language, a 
language as malleable as a piece of soft aluminum.

Scott Krueger
N92EX