Running dry?

Recently, Greg Copeland posted:

Is this common? How many run their tank(s) dry as part of their fuel
management strategy? If you don't run dry, why not?

Two main reasons; there are better ways to gauge your fuel consumption
rate, for example, logging how much fuel you put back in the tank after
the flight; and why play with the trim to keep the plane going in a
straight line, then start all over again with that fiddling when you
switch tanks?

Aside from the
heat beat skipping which is sure to follow the first couple of times,
what's the down side to this strategy?

Besides being pointless? How about being uneccesarily risky?

Neil

On Thu, 18 Aug 2005 17:21:16 +0000, Neil Gould wrote:

Recently, Greg Copeland posted:

Is this common? How many run their tank(s) dry as part of their fuel
management strategy? If you don't run dry, why not?

Two main reasons; there are better ways to gauge your fuel consumption
rate, for example, logging how much fuel you put back in the tank after
the flight; and why play with the trim to keep the plane going in a
straight line, then start all over again with that fiddling when you
switch tanks?

Aside from the
heat beat skipping which is sure to follow the first couple of times,
what's the down side to this strategy?

Besides being pointless? How about being uneccesarily risky?


"I know of no accidents that have occurred because an engine would not
restart when supplied with fuel in flight. I have personally done this
literally thousands of times myself, and never seen more than a couple of
seconds of interruption, even when I was completely unaware the engine was
about to quit. If we count all the people I know who routinely did it,
there are literally millions of such events." -John Deakin

"This is simply not true of recips. When a recip runs out of fuel, nothing
else has changed. The spark is still there on every power stroke, the
piston is still pumping air, driven by the prop, which is nearly
impossible to stop, inflight even when you want to. Two of the "three
necessities" (fuel, air, spark) remain, totally unaffected by the lack of
fuel." -John Deakin

So what risk factor can you assign to what is more or less, a non-event?

As for the "why", John Says, "I'd like to take a look at fuel management,
and since my method sometimes calls for running a tank dry, let's get that
out of the way first." In other words, its his strategy for fuel
management which lets him known and understand how much he really has in
reserve and how much can he get out of the "unuseable". Should he have an
event where he has to bite into his reserves, he never has to say, "I sure
hope I have enough. I wonder how much is there".

This is not to say that I've bought into it, but hey, someone has to play
Devil's Advocate!

Greg

Recently, Greg Copeland posted:

On Thu, 18 Aug 2005 17:21:16 +0000, Neil Gould wrote:
Besides being pointless? How about being uneccesarily risky?


[...]
So what risk factor can you assign to what is more or less, a
non-event?

It's a non-event *if* the tank runs dry at a convenient time and place,
*if* the engine restarts (I've had one heck of a time restarting a warm
fuel-injected engine at times), etc. Even if these risks are low, they're
still uneccesary, so I'll stand by my opinion. ;-)

As for the "why", John Says, "I'd like to take a look at fuel
management, and since my method sometimes calls for running a tank
dry, let's get that out of the way first." In other words, its his
strategy for fuel management which lets him known and understand how
much he really has in reserve and how much can he get out of the
"unuseable". Should he have an event where he has to bite into his
reserves, he never has to say, "I sure hope I have enough. I wonder
how much is there".

What's the point in all of this? If he can't figure out fuel consumption
rates from the amount of fuel that he replaces after the flight, what good
is running the tanks dry? One is supposed to have a 45-minute reserve VFR;
that's quite a bit more fuel than running dry. The whole idea is *not* to
run dry. To me, it sounds like a fools game to do otherwise.

Neil

On Thu, 18 Aug 2005 19:02:46 +0000, Neil Gould wrote:

Recently, Greg Copeland posted:

On Thu, 18 Aug 2005 17:21:16 +0000, Neil Gould wrote:
Besides being pointless? How about being uneccesarily risky?


[...]
So what risk factor can you assign to what is more or less, a
non-event?

It's a non-event *if* the tank runs dry at a convenient time and place,
*if* the engine restarts (I've had one heck of a time restarting a warm
fuel-injected engine at times), etc. Even if these risks are low, they're
still uneccesary, so I'll stand by my opinion. ;-)


At a convenient time? That's the difference between running out of fuel
and running the tank dry. After all, if you chosen to run the tank dry,
it better be because its both a convenient time and place. If you allowed
your self to run out of fuel at an "inconvenient time and place", then you
ran out fuel, which is not what is advocated here. Remember, this is
part of a fuel management strategy and not blindly flying until the tank
reads empty and the engine sputters.

Deakin's article clearly spells out that there are some planes which
this should not be done on. Fuel injected engines is probably one such
category to not try this on because of vapor-lock issues. In most
carborated engines, in most planes, I must admit it sure sounds like a
non-event to me. Again, as even Deakin points out, there are exceptions
to every rule; whereby he even provides one.

Also, I do thank you for sharing your opinion.

As for the "why", John Says, "I'd like to take a look at fuel
management, and since my method sometimes calls for running a tank
dry, let's get that out of the way first." In other words, its his
strategy for fuel management which lets him known and understand how
much he really has in reserve and how much can he get out of the
"unuseable". Should he have an event where he has to bite into his
reserves, he never has to say, "I sure hope I have enough. I wonder
how much is there".

What's the point in all of this? If he can't figure out fuel consumption
rates from the amount of fuel that he replaces after the flight, what good
is running the tanks dry? One is supposed to have a 45-minute reserve VFR;
that's quite a bit more fuel than running dry. The whole idea is *not* to
run dry. To me, it sounds like a fools game to do otherwise.

Fair enough.


Neil

Greg