From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Fuel feed practice/plumbing
To: lml
Date: Sun, 04 Aug 2002 21:12:17 -0400
Message-ID: <web-1681996@logan.com>
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Posted for "Robert Smiley" <rsmiley@centurytel.net>:
Clarification,

Each main tank (16 gal) has its own facet pump which pumps into a Tee which
is connected to a two way valve.  The normal position of the valve is to the
header tank. The alternate position is to fill up the wing tip tanks,(5 gal
each). When the header demands fuel via the auto fill mechanism, both pumps
start to fill up the top 5 gallons of the header tank thus there is 5.75
gallons in reserve to land within 30 minutes if there is a failure.   30
minutes is about 100 miles distance.  Also the facet pumps offer some check
valve tendancies thus if one pump were to fail the other pump would still
pump into the header with a small portion of fuel leaking into the other
main tank through the other facet pump.  You are right murphy's law can
happen but then if power failure occurs you lose the boost pump.  Header
tanks are insufficient for fuel injection pressure without at least one
pump. So you pray the mechanical pump continues to function.

I of course have the option to select one, the other or both mains to pump
into the header tank by the flip of an electrical switch as opposed to a
mechanical valve.

You are also right, Ian.  I have lost a main fuel cap.  Here's how it
happened.  I filled up the tank. Put the cap back on.  "Interesting?  the
snap down took excessive pressure???  I didn't test  the cap to see if it
was secure.  Took off from West Jordan SLC No 2 for Provo.  In the air I
smelled fuel, looked out the right side and there it was, I was seeding the
clouds with fuel.  Landed at  Provo to visit a friends Lancair construction
project and he graciously loaned me a cap.

Lesson,  Check your cap for security every time by physically grabbing it
with your fingertips and fingernails and try to lift it off the wing.  Also,
if something is different in your normal operations, check it out for
possible reasons and put up caution signals in your mind and search out the
reason why things are different before you take off.

BTW, I will be flying to Witchita, KS this week to attend a control line
model airplane contest.  Any Lancair builders in the area? and where is a
good place to land and to stay?

Bob Smiley
N94RJ