Fuel tank balance

Is there any reason to drain fuel tanks in any way other than
symmetrically in normal flight? I notice that most aircraft have
complex controls for fuel flow from the tanks, and I wonder if there
are things one is suppposed to do during normal flight, or if this is
just to provide for possible equipment failures or a need to shift the
center of gravity of the aircraft in an emergency.

--
Transpose mxsmanic and gmail to reach me by e-mail.

"Mxsmanic" wrote in message
...
Is there any reason to drain fuel tanks in any way other than
symmetrically in normal flight?

Yes

Mxsmanic wrote:
Is there any reason to drain fuel tanks in any way other than
symmetrically in normal flight? I notice that most aircraft have
complex controls for fuel flow from the tanks, and I wonder if there
are things one is suppposed to do during normal flight, or if this is
just to provide for possible equipment failures or a need to shift the
center of gravity of the aircraft in an emergency.

Because you need to find the fuel. Some planes have a "both" selector
but not all are set up where that would work. Also, for twins you need
to be able to transfer the fuel out of the tank from the dead engine
into the good engine since the good engine burns more fuel when its
working by itself.

-Robert

Robert M. Gary writes:

Because you need to find the fuel. Some planes have a "both" selector
but not all are set up where that would work. Also, for twins you need
to be able to transfer the fuel out of the tank from the dead engine
into the good engine since the good engine burns more fuel when its
working by itself.

Okay, but that's an exceptional situation. For a normal flight, do
you have to change the fuel settings? I know Lindbergh did, but that
was an unusual aircraft.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Yup pretty darn complex. In Our Mooney you have to go from right to left
(or was that left to right?) about ever 30 miinutes or so... I forget...
I think the procedure takes up 10 or so pages in the POH though....

Jon Kraus
'79 Mooney 201
4443H @ UMP

Mxsmanic wrote:
I notice that most aircraft have
complex controls for fuel flow from the tanks, and I wonder if there
are things one is suppposed to do during normal flight, or if this is
just to provide for possible equipment failures or a need to shift the
center of gravity of the aircraft in an emergency.

Mxsmanic wrote in
:

Robert M. Gary writes:

Because you need to find the fuel. Some planes have a "both" selector
but not all are set up where that would work. Also, for twins you
need to be able to transfer the fuel out of the tank from the dead
engine into the good engine since the good engine burns more fuel
when its working by itself.

Okay, but that's an exceptional situation. For a normal flight, do
you have to change the fuel settings? I know Lindbergh did, but that
was an unusual aircraft.


as far as left/right/both/off, normaly you set it on both and forget it.
some planes have left/right/off, I alternate every 15 min.

the more complex adjusting of the fuel comes from the mixture control.

new_CFI writes:

the more complex adjusting of the fuel comes from the mixture control.

I don't understand the mixture control, either. Fortunately I can
have MSFS worry about that.

I'm surprised at all the fiddling that pilots are expected to do with
their propulsion units, as compared to other types of vehicles. Bad
enough that one must know how to fly, but apparently one must be a
qualified engine mechanic as well.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Jon Kraus writes:

Yup pretty darn complex. In Our Mooney you have to go from right to left
(or was that left to right?) about ever 30 miinutes or so... I forget...
I think the procedure takes up 10 or so pages in the POH though....

Perhaps this will sound stupid, but why wasn't the aircraft designed
to pull fuel simultaneously from both, or at least to connect the two
together?

--
Transpose mxsmanic and gmail to reach me by e-mail.

In article xwhRg.1082$Rp3.261@dukeread12, "new_CFI"
wrote:

as far as left/right/both/off, normaly you set it on both and forget it.
some planes have left/right/off, I alternate every 15 min.

Every 15 minutes? That seems a bit excessive. Once an hour should keep
things pretty much in balance. If you want to get fancy, do your first
switch after a half hour, then every hour after that.

On a long flight, keeping track of fuel is more than just mindlessly
switching tanks every so often. As an example, on a recent flight I took,
we started out with 72 gallons usable, burned about 16 gph in cruise. The
POH prohibits takeoffs on any tank less than 1/4 full.

We had about 3 hours to our destination, at which there was no fuel
available; we had another 1/2 hour hop to someplace with fuel on the way
back.

We burned one tank down to 20 gallons, then from the other one for the rest
of the 3 hour leg. When we had our destination in sight, we switched to
the fuller tank for the landing. We took off again on that fuller tank,
and switched back to the lower one most of the 1/2 hop to where we could
get fuel, then switch back to the fuller one again in the pattern and
landed on that. This make sure that on both landings, we were running off
a tank that was just a little under half full, so we wouldn't have any
problems if we needed to do a go-around. It also mean that if we landed at
our fuel spot and discovered we couldn't get any fuel for some unexpected
reason, we still had a half-full tank to take off on again.

Moral: I'd rather have one half-full tank and one almost empty one than
have two that are 1/4 full.

Mxsmanic wrote in
:

new_CFI writes:

the more complex adjusting of the fuel comes from the mixture control.

I don't understand the mixture control, either. Fortunately I can
have MSFS worry about that.

I'm surprised at all the fiddling that pilots are expected to do with
their propulsion units, as compared to other types of vehicles. Bad
enough that one must know how to fly, but apparently one must be a
qualified engine mechanic as well.


Have you ever driven a non-turbocharged car from a low lying city up into
the mountains, like above 5,000' MSL? If you did, you would understand why
the pilot has to manipulate the mixture.

Also, the design of the aircraft engine is such that once it is started,
the engine driven magnetos provide the spark to keep it running. You can
have total electrical failure and the engine will keep on running. How do
you stop the engine after you land?

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)