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From: "Thisted" <msbt@csi.com>
To: <lancair.list@olsusa.com>
Subject: header tanks
Date: Tue, 25 Apr 2000 21:26:04 -0400
Mime-Version: 1.0

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Gary,
I agree with you in principle that any fuel system that requires attention
every 30 minutes is a disaster waiting to happen.

First a few facts:
1.    Fuel pumps pump unregulated fuel, which means that the fuel flow is
higher than actual fuel consumed by the engine.
2.    The Lancair utilizes two electric fuel pumps.
3.    The Lancair does not have a fuel valve with left-right-both-off
functions.
4.    Header tank acts as a reservoir.

The complexity and equipment involved to operate without the header tank
includes return reservoir, pumps and regulator for metered fuel and return
lines as well as a fuel valve amongst other things. It is possible to go
that route and some have.

The system as it was designed for the Lancair is simple and bullet proof. I
do think that an automatic fuel transfer system( AFTS) is well worth it.
With that installed you essentially have the best of both worlds. You don't
even have to switch fuel tanks every 45 minutes as you are used to in many
certified aircraft. You will also be able to perform aerobatics maneuvers
because you have the header tank and can leave the mains dry. The header
tank also serves as a way to move weight from one area to another to
accommodate any CG issue.

With all due respect. Your analogy regarding Russian Roulette is a bit
harsh. The system is as simple as it comes. It has dual fuel pumps, no fuel
valve and with the addition of the AFTS it is virtually bullet proof. Some
thing that can not be said about many fuel systems. It is less unsafe than
having a single fuel pump fail without any backup in my opinion. The
builders that eliminate the header tank often install a second pump for
backup.

I think you are making to much of a deal out of nothing. Accident reports
seem to indicate that fuel starvation is not a problem with 2 seat Lancairs.
Even without the AFTS unit it quickly becomes second nature, like switching
fuel tanks. I'm all for reduction of workload so I bought an AFTS for mine,
but it is a good and simple system, with or without.

So long
Bo thisted


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