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Walter,
You
said that "[you] think that a
good pilot always knows how much fuel he has."
I
respectfully disagree and I think YOU are on the slippery
slope. I think a that a good pilot realizes that he
DOESN'T know how much fuel he has, that he MAY have less than he
thinks, and therefore plans conservatively.
It's
the pilot who thinks he has better information than he really does that is more
likely to get dead than the conservative pilot. In fact, I'm not
sure I'd feel comfortable flying with someone who thinks they have more accuracy
in their remaining fuel than than they probably
do.
Knowing how much fuel you have in flight requires knowing TWO things: 1)
Burn rate, and 2) Starting usable fuel amount (and knowing how much fuel a
specific flight will require adds in many more variables).
Unless I have TOPPED my tanks on a completely
LEVEL tarmac, even perfectly accurate fuel flow doesn't really do much
for me. Because the bigger issue is "How much fuel did I have to
start with" (does Tony D. come to mind?)?
And here's the meat of the issue and where I think we
really disagree: Measuring fuel flow to +/- .2 GPH doesn't do
squat. 5 hours in the air doesn't even equal a gallon. It would
be a minor miracle if you could look in your tanks, sitting on an
average tarmac, and be within even 2 gallons of accuracy. And if you think
your fuel flow is +/- 1%, under the range of conditions in which you
fly, then I certainly don't want to fly with you. So, how accurate
are YOU trying to be with fuel fuel flow and remaining
fuel?
Go ahead and measure with a micrometer and cut with a
hatchet. I won't hold the piece of wood.
And I CERTAINLY didn't say I don't CARE about how
much fuel I have or how much I burn (please reread my post). I
am just realistic in recognizing that I don't have perfect information, so I'll
be conservative.
So I'll stick with my
comment, which was:
"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."
Maybe you turbo guys are different - no matter what
altitude you fly you maintain the same cruise power setting. It's just one
number to remember. But that's not the case for us normally aspirated
guys. My fuel flows vary significantly on EVERY flight. I don't care
to memorize every burn rate at every power setting. I make conservative
estimates for flight
planning.
Don't ask me my Lancairs burn rate - unless you just
want a rough estimate, and I won't ask what the actual gas mileage of your SUV
is (you'll probably reply that you drive a Honda Insight and I'll look
really stupid).
If you don't want to fly with me, I'm not
offended. Happy
flying.
Matt
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