Running dry?

Robert M. Gary wrote:
They should stop being cheap *******s and just buy the damn fuel
computer. Then you know how much fuel is in each tank. You back woods
pilots worry me.

I fly a 1945 Aeronca Champ. It has a single 13-gallon fuel tank that
sits above my legs on the cabin side of the firewall. If there is a
leak, I will feel it smell it.
The Champ has no electrical system, so it cannot power a computer.
I plan for 4-gallons/hour, but in actuality, it burns 3.5 to 3.75 gph.
The most fuel I have put in at one fillup was 12 gallons.

Robert,

I have drained the tanks before and used that measurement to
calibrate the computer.


In that case, I take back most of what I said. I stand by my statement
that you can apply the technique without scaring anybody, though.

--
Thomas Borchert (EDDH)

Jay,

I'm sorry, was I calling someone a name?


Saying "That is possibly the dumbest thing..." kind of implies the
author is dumb in most interpretations, doesn't it? John Deakin sure is
a lot of things. Dumb is definitely not among them.

--
Thomas Borchert (EDDH)

"Robert M. Gary" wrote in message
oups.com...
I bought a fuel computer (JPI add-on to my EDM). I know exactely how
much fuel is in each tank.


Assuming the last person who filled it filled it all the way. I find a
discrepancy of about 10 gallons seems to happen depending on how the tanks
are filled.


Michael

Your "K" factor must first be corrected during several top offs. After
that most of the discrepency is caused by various methods of filling to
various levels. Furhter, most gas pumps have cummy metering, and those
that are ripping you off are easy to tell with the JPI FF.

To be most exact, one needs to fill the tanks yourself, from the same
trusted pump. After that the JPI will easily be within .1 gallons of
actual use. Time and time again.

karl

karl gruber wrote:
Your "K" factor must first be corrected during several top offs. After
that most of the discrepency is caused by various methods of filling to
various levels. Furhter, most gas pumps have cummy metering, and those
that are ripping you off are easy to tell with the JPI FF.

Takes three flights, minimum. A fourth can be used to tweak it tightly.

I'm sorry, was I calling someone a name?

Saying "That is possibly the dumbest thing..." kind of implies the
author is dumb in most interpretations, doesn't it? John Deakin sure is
a lot of things. Dumb is definitely not among them.

Sorry, even Einstein had dumb ideas. This is one of Deakins...

In fact, I would never have guessed that this kind of a hair-brained "fuel
management" procedure would merit a serious discussion in these newsgroups.
To even contemplate running a tank dry in the air, let alone propose it as a
standard -- even beneficial (?!) -- procedure, makes for astonishing
reading.

Although this thread *does* answer a question that has bugged me for a very
long time. I've often wondered how it was possible that so many NTSB
reports ended with "fuel exhaustion" as an explanation.

Now I know.

(And, no, before any "English as a second language" folks misinterpret the
meaning of my post, I DON'T mean that any particular crash happened because
the pilots were purposefully running a tank dry. Rather, it's the "let's
extend our fuel range to the maximum possible" attitude that kills people --
and this thread goes a long ways toward explaining that mentality.)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Rather, it's the "let's
extend our fuel range to the maximum possible" attitude that kills people --
and this thread goes a long ways toward explaining that mentality.)

But this is what aviation =is=.

Aviation is all about limits. We are held up on nothing more than a
blast of air (ob politics: ... and will be brought down by nothing more
than a blast of hot air). In order for that to work, airframes are made
as thin as they can, engines are made as light as they can, reserves are
as thin as they can be... all up to a point. Where that point =is=
(beyond the FARs) is a matter of comfort and physics. If you didn't go
flying unless you had a guaranteed two hours reserve, you'd never go
anywhere. So we cut it down to forty-five minutes - or even half an
hour in clear daylight. Some would consider this reckless, some would
consider it ultra-conservative, but it is what it is - a compromise.

Having only {fill in} reserve is stretching it.

Jose
--
Quantum Mechanics is like this: God =does= play dice with the universe,
except there's no God, and there's no dice. And maybe there's no universe.
for Email, make the obvious change in the address.

Jay Honeck wrote:

In fact, I would never have guessed that this kind of a hair-brained
"fuel management" procedure would merit a serious discussion in these
newsgroups.

The fact that you consider it "hair-brained" does not make it so.

To even contemplate running a tank dry in the air, let alone propose
it as a standard -- even beneficial (?!) -- procedure, makes for
astonishing reading.

Huh. I've run my tanks dry on occasion, for a couple of reasons. First
of all, I wanted to calibrate my new fuel flow gauge. With 56 gallons
in the tanks (28 on each side), I ran one side dry and noted the fuel
used - good within 0.1 gallons out of 28 - I was happy. After I landed,
with 15 gallons left in the other tank (and with a fuel burn on that
trip of about 8.5 gal/hr) I still had almost a 2 hour reserve. It takes
me about 3 seconds to switch tanks, and I do so as soon as I hear the
engine start to stumble. It never stops firing, and it CERTAINLY never
stops rotating - not at 180 Kts TAS at 11.5K ft.

Plus, when I would run one tank dry BEFORE I had the FF gauge, it would
be the only time that I would know EXACTLY how much fuel I had left in
the plane. Seems like something worth knowing.

I'm totally confused as to what the dangerous part of this action might
be. The engine was running before - it'll run after 3 seconds of not
quite getting enough fuel. And since the prop doesn't stop turning (I
have to slow below about 90 Kts before that would happen), it starts
right back up as soon as the fuel returns.

Although this thread *does* answer a question that has bugged me for a
very long time. I've often wondered how it was possible that so many
NTSB reports ended with "fuel exhaustion" as an explanation.

Now I know.

I don't really think that you do. As I noted, I can run a tank dry and
have anywhere from 2.5 to 5 hours of fuel (depending on how fast I want
to go) left in the other side - that's hardly a "fuel exhaustion"
danger - some airplanes don't carry that much fuel when they take off
full.

--
Marc J. Zeitlin
http://www.cozybuilders.org/
Copyright (c) 2005

On Fri, 19 Aug 2005 14:34:27 -0700, "RST Engineering"
wrote:

The primary function of the fuel gauges in most light aircraft is to
indicate when the master switch is on.

And they *usually* work for that.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Jim



I did a precautionary landing at GDW. A check showed no leak and the
level was where it should be. When I fired back up the gauge was
reading properly.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com