Running dry?

On Sun, 21 Aug 2005 08:24:49 -0700, RST Engineering wrote:

[snip]
Would I run one dry where there are nothing but airports and soybeans
underneath? I might. Depends on what I'm trying to accomplish. I
think Deakin knew what he was talking about and expected at least a
MODICUM of intelligence on the part of his readers.

In fact, Deakin is very clear that if you can't figure out these types of
details, you probably shouldn't be flying at all. He also states there
are exceptions to every rule and even provides one. He clearly is making
the distinction betweena purposeful act of running a tank dry at a
planning time and place is not confusing this with running out of gas;
which Jay seems to be completely confused by.

Ultimately, I believe Deakin's intention is to make pilots talk and
compare notes. Making pilots think about the results of their actions is
always a good thing, even if you don't buy into his method. Does it
really matter is someone think's this is a crazy idea? Nope. It does
matter that we came together and talked. I think there's been some really
great posts here...and I feel smarter for having asked and learned.

Lastly, I should add, I believe this type of procedure is SOP for many
military piston pilots where range it critical to their mission. Please
correct me as needed. If this were a high risk venture, I doubt it would
SOP. As such, I believe the risk of a non-start for many planes is very
low. IMHO, the only remaining question is, what risk are you willing to
tolorate and what is the REAL risk of a non-start. Is the risk one in a
million? One in a billion? One in a hundred? I dunno.... thus the FUD
had lots of room to creep in...

Greg

Would I teach running a tank dry to a student? Most likely not. Would I
recommend the procedure be taught on a BFR? Most likely not. Would I run
one dry with trees, rocks, or water underneath (say, from Scottsbluff to
Sacramento)? Most likely not.

Would I run one dry where there are nothing but airports and soybeans
underneath? I might. Depends on what I'm trying to accomplish.

Let's talk about what you're trying to accomplish.

Are you:

- Checking the accuracy of your fuel gauges?

That's absurd -- anyone who relies on fuel gauges is an off-field landing
waiting to happen.

- Trying to fly the absolute maximum distance your fuel will allow?

That's unwise. Anyone who tries to stretch endurance guarantees headwinds.

- Trying to avoid buying a fuel totalizer?

Man, just go buy the stupid thing. It'll tell you your fuel burn to within
a few ounces.

What other reason is there to run a tank dry on a GA plane? I mean,
c'mon -- we're not doing maximum endurance search and rescue flights over
the Pacific here -- we're flying to St. Louis for lunch! There is
absolutely no logical reason that I can see to purposefully run a tank dry
in flight on a GA plane. None. Zero. Zip. Nada.

Let's think about why an engine would not restart with one dry.

In my plane, it can take 10 to 12 seconds for fuel to feed from one of our
tip tanks. If I ran a main tank dry, the prop stopped, and I switched to
that tip, I suspect that would be the longest 10 seconds of my life. I'd
prefer not to take that chance, thank you.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay, during a period of "shore duty" in the Navy, I had the misfortune
to ocassionly fly the SNB (Secret Navy Bomber) known to civilians as
the Beachcraft D-18. It had no electric fuel pumps, but rather a
mechanical "wobble" pump located on the floor between the pilots.

It was standard procedure to run each tank dry. When the engine quit,
the pilot switched tanks and started pumping the wobble pump like crazy.
Never had a problem.

I find that many of your posts are colored by the limited types of
aircraft that you have flown and the limited conditions under which
you have flown those aircraft.

Bob, are you really justifying running gas tanks dry in modern GA planes
because of your experience flying an antique POS that didn't have fuel
pumps?

Just because you survived it, doesn't make it smart.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Not without a change to the regularly checked and serviced fuel gauges.

I used to have a 1946 Chief. It had one 13 gal tank in front of you
with a aux feed tank behind you. Running that tank dry would have been
a very, very bad idea. There is no guarantee that the aux tank will
drain to the main tank faster than the plane drinks at all attitudes.

"Jay Honeck" wrote:
In my plane, it can take 10 to 12 seconds for fuel to feed from one of our
tip tanks. If I ran a main tank dry, the prop stopped, and I switched to
that tip, I suspect that would be the longest 10 seconds of my life. I'd
prefer not to take that chance, thank you.

I've only flown a couple of models with tip tanks (Cherokee Six and
aftermarket tips on a Bonanza). In both of those, takeoffs and landings
are done on the main tanks. I'm guessing that's standard for all tips.
Wouldn't it make more sense to drain the tips, *then* drain the mains?

Not in my aircraft. I spend money to make mine work. The wife likes
that better than looking down at the Sierras without the motor running.

Frankly Jay if you do not wish to ever run a tank dry that is your
decision. I am not critical of it. However, I do not agree with your
assertion that running a tank dry implies the same sort of situational
awareness that leads to exhausting all fuel in flight and making an
off airport landing/crash.

Running a tank dry probably won't lead to anything worse than sucking all
the crap out of your gas tanks -- but you're missing my point.

Pilots who end up landing off-airport (or, worse, dying) because of
something as stupid as running out of gas have something mis-wired in their
heads. They apparently have learned to feel that it's okay to run on the
bleeding edge of empty, and I'll bet dollars to donuts their fuel management
stupidity wasn't a one-time affair.

Behavior is progressive. You get away with running low on gas once, maybe
you think you can do it again. You look in the tanks, can't see any fuel,
but say to yourself "Well, let's see; I flew only 1.4 hours yesterday, and
I was full before that flight, so I'm SURE I can make it another 3 hours..."

And you get away with THAT.

And then you start trying to extend your range to the max by running a tank
dry before switching tanks, and you get away with THAT. And, before you
know it, by God, you've figured out how to fly almost 6 hours without
refueling. Now you think you're really hot ****, and you can entirely skip
a planned refueling stop, and save yourself an hour or more -- and you get
away with THAT a few times.

Until that last flight, when the headwinds are more than predicted, and your
guesstimated fuel is off by 20%. Suddenly your tank is running dry, and
you realize that you already ran the *other* tank dry -- and you're heading
for terra firma, pronto. It's not the fact that someone routinely runs a
tank dry before switching that is dangerous; rather, it's the attitude that
this kind of fuel "management" indicates that I find scary.

Here's an easy way to make sure you never run out of gas.

1. Refuel after every flight. You will be ready to go for your next flight,
and can rest assured that you have gas on board. (Renters will have to
switch this to refueling BEFORE every flight.)

2. Install a fuel totalizer. They are cheap (in aviation money), and will
tell you your fuel usage to within a few ounces. (Sorry, renters. Get on
the FBO to install one.)

3. Never try to stretch your range. Bite the bullet, land and buy gas.

4. Measure your gas with your watch, never your fuel gauges.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In fact, Deakin is very clear that if you can't figure out these types of
details, you probably shouldn't be flying at all. He also states there
are exceptions to every rule and even provides one. He clearly is making
the distinction betweena purposeful act of running a tank dry at a
planning time and place is not confusing this with running out of gas;
which Jay seems to be completely confused by.

The only thing I'm confused about is how a group of pilots can sit here and
argue -- on the STUDENT forum, of all things -- that running a gas tank dry
in flight, on purpose, is a wise thing to do.

Apparently you can't grasp the subtlety of what I'm saying, so allow me to
bludgeon you with it: Any pilot who knowingly, willingly and routinely runs
gas tanks dry in flight displays a cavalier attitude toward fuel management.
Running a tank dry by accident indicates poor planning. Running a tank dry
on purpose indicates poor fuel management. Both are dumb. Both are
dangerous.

To suggest otherwise in a forum where student pilots gather is unwise.

Lastly, I should add, I believe this type of procedure is SOP for many
military piston pilots where range it critical to their mission. Please
correct me as needed. If this were a high risk venture, I doubt it would
SOP. As such, I believe the risk of a non-start for many planes is very
low. IMHO, the only remaining question is, what risk are you willing to
tolorate and what is the REAL risk of a non-start. Is the risk one in a
million? One in a billion? One in a hundred?

You ask this question as if we are on an equal situational footing with
military pilots. 99.999% of the people reading this post are GA pilots (or
students) whose main concern will be missing a day of work if they're late
getting back from vacation. There is NO reason for any pilot here to fly to
the maximum range of their aircraft, and to talk about using a procedure
that is "SOP for many military piston pilots where range is critical to
their mission", as if that is justification for running a tank dry, is just
crazy talk.

Do you run your engine as low as possible on oil, too, just to extend the
range between oil changes? Shoot, according the book, my Lycoming O-540
will run on as little as 2 quarts of oil -- why am I dumping those other 10
quarts in, anyway?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

I've only flown a couple of models with tip tanks (Cherokee Six and
aftermarket tips on a Bonanza). In both of those, takeoffs and landings
are done on the main tanks. I'm guessing that's standard for all tips.
Wouldn't it make more sense to drain the tips, *then* drain the mains?

We always take off and land on the mains. Once airborne, we'll fly for 30
minutes on that tank, then 30 minutes on the other main.

If the flight is longer than an hour, we will then run the tips in 15 minute
increments. (Or 10, or 20 -- whatever it takes to keep them even when we
arrive at our destination.) In our plane, having 17 gallons WAY out at the
end of the wing means that you had better keep things balanced, or you're
gonna be flying tipped at an angle pretty quickly!

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"