To: lancair.list@olsusa.com
Date: Wed, 31 Mar 1999 17:35:15 -0600
Subject: LNC2 Fuel system plumbing
Message-ID: <19990331.173519.12110.1.Earl_Schroeder@juno.com>
From: Earl E Schroeder <earl_schroeder@juno.com>
Mime-Version: 1.0

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>>
Marv,

>>[Interesting approach, Earl... do you have the usual shutoff for the
header,
>>and if so, I assume you close that when pumping directly from the
wings?
>>And when you say that the tee at the firewall is 'valved' up to the
header,
>>is that what you're refering to?  Anxious to hear more.....   <Marv>  ]

Yes the 'valved' is the usual valve from the header tank and is closed
when pumping directly from the wings.  I also have a rotometer in the
line from the wings after the left-right-off valve and before the tee at
the firewall.  This probably will not be too useful since the Facet pumps
pulse but I hope to be able to see 'bubbles' to verify an empty wing tank
on purpose or by accident.  BTW, I had to fabricate an extension to
operate the on-off header valve since it is located too far forward to
reach by hand.  In retrospect, that probably should be within arm's reach
but I couldn't figure out a way of doing it when using the std double
sump on the header tanks and keeping the piping length minimum as well as
the fitting count low.  I may be over sensitive to vapor lock but I've
heard some nasty stories from supposedly 'auto' gas users.... we can't
even be absolutely sure what we are getting out of aviation pumps these
days.  Plus, if I have an unfortunate complete electrical failure, I
wanted to give gravity and the engine driven pump a fighting chance of
fueling the Lyc to a safe landing.   Earl


[Rotometer??  Can I assume (once again) that this is a type of flowmeter?
Who makes it and where did you get it?

I am inclined to keep everything in the fuel system as simple as
possible, so will probably just run the transfer pumps to the header
and be done with it.  Although a crossover to level out wing fuel in case
of a single transfer pump failure makes a lot of sense to me.  

Because I've mounted the hydraulic power pack on the firewall above 
the passenger footwell, my dump valve will be on the right side of the
NG tunnel.  That puts my header tank shutoff on the pilot's side, and I
like your idea about the extension to operate it... would make it
possible to mount the valve right at the sump and really keep that
plumbing run short.  Tomorrow I'll check that location to see if it 
isn't in the way of the rudder pedals.  Thanks again for the tips.  Much
to think about.   <Marv>  ]