Sender: "Marvin Kaye" <marv@lancaironline.net>
To: lml@lancaironline.net
Date: Sat, 05 Mar 2005 15:29:31 -0500
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From: "Matt Hapgood" <hapgoodm94@alum.darden.edu>
Subject: RE: [LML] Re: FADEC Rough idle explanation
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In-reply-to: <list-771393@logan.com>

I hear both of you and agree wholeheartedly with PART of what you are
saying.

I have stated quite clearly that I think it is EXTREMELY important to have a
good idea how much fuel is REMAINING.

But flight planning to within 0.1 GPH is pure folley in my aircraft, because

1.  I rarely am able to tell,  within even 2 gallons per wing, my STARTING
fuel amounts, and
2.  Flying a NORMALLY ASPIRATED plane, my fuel burn is impacted
significantly by weather (which altitude I choose and WIND), and ATC (which
altitude they assign).

Typically these differences account for more than 1 GPH.

So, given these two facts of flight planning, I'll stick to my ORIGINAL
point (adding back the parts that keep getting clipped out to try to make a
point about something I don't agree with):

"I personally don't really care whether I burn 8 GPH or 9 GPH in cruise.
I'm not going to fuel plan that precisely.  I can't.  I don't always know
whether I will fly at 6,000' or 12,000' and that makes a WHOLE lot larger
difference in fuel planning than leaning.  And just as in the car, I'd land
and fuel up if I got lower on fuel than expected on a trip."

Please note that the very important part about FUEL PLANNING.  That is MY
POINT.  PERIOD!  If I can't PLAN any more detailed, I'm not going to
memorize some tables about fuel burn for every scenario only to have it be
meaningless.  AGAIN, ask me my fuel burn and I'll tell you - I DON'T KNOW to
within more than about 1 GPH.

So I'll cease typing on this thread and let you all continue to tell me how
I need to know my fuel flow better than the 1 GPH (slightly more than 10%
CONSERVATIVE) accuracy that I indicated.  And I'll keep checking my
REMAINING fuel and landing when I realize I won't have an hour reserve on
landing.

Call me chikin, call me innacurate.  Call me alive.  You guys keep stressing
over a 0.2 GPH burn rate... I kinda enjoy the humor in it.

Matt