Fuel tank balance

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)

Marty Shapiro writes:

Have you ever driven a non-turbocharged car from a low lying city up into
the mountains, like above 5,000' MSL?

I don't know. I think so, since some of the cities north of me were
around 7000'.

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?

By cutting off fuel, but that's a simple switch or valve. It seems
that there are a lot of other complicated adjustments to worry about.

By now I would have expected that powerplant manufacturers would have
built automated systems to handle much of this; indeed, it was
possible even before the age of computers.

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

Mxsmanic wrote in
:

Marty Shapiro writes:

Have you ever driven a non-turbocharged car from a low lying city up
into the mountains, like above 5,000' MSL?

I don't know. I think so, since some of the cities north of me were
around 7000'.

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?

By cutting off fuel, but that's a simple switch or valve. It seems
that there are a lot of other complicated adjustments to worry about.

By now I would have expected that powerplant manufacturers would have
built automated systems to handle much of this; indeed, it was
possible even before the age of computers.


mixture works like this:

its a fule to air ratio. x:y... so as you climb and air density
decreases the amount of fule require to keep the ratio constant,
changes. So, the amout of fuel you send to the engine needs to be less.
Thats where the mixture controll comes in. If you don't have the Pilots
Handbook of Aeronautical Knowledge, there is a good explanation of
it....if you don't have it; you can download it from the faa website.
If you need the link Ill post it, but I have to run….

new_CFI writes:

its a fule to air ratio. x:y... so as you climb and air density
decreases the amount of fule require to keep the ratio constant,
changes. So, the amout of fuel you send to the engine needs to be less.
Thats where the mixture controll comes in. If you don't have the Pilots
Handbook of Aeronautical Knowledge, there is a good explanation of
it....if you don't have it; you can download it from the faa website.
If you need the link Ill post it, but I have to run….

I have the handbook. I pretty much understand the explanation, I just
wonder why the pilot adjusts it. You'd think that the engine would be
able to measure the static air pressure and adjust the mixture for
itself. Cars have complex engine computers, so why not aircraft
engines? Of course, if aircraft engines had the same unreliable
software that they put in cars, they'd drop out of the sky, so it
would have to be verified a lot more, and the engine would have to be
able to run without it.

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

Mxsmanic wrote:
You'd think that the engine would be
able to measure the static air pressure and adjust the mixture for
itself. Cars have complex engine computers, so why not aircraft
engines?


There are aircraft engines that do (piston).. Look up FADEC.

But if the non FADEC engine can give similar performance with a skilled
operator, then what do you want to spend your pennies on.. a new fangled
electronically controlled engine? or keep using the old one with a few
extra knobs and dials.

Dave S wrote:

Mxsmanic wrote:
You'd think that the engine would be
able to measure the static air pressure and adjust the mixture for
itself. Cars have complex engine computers, so why not aircraft
engines?

There are aircraft engines that do (piston).. Look up FADEC.

But if the non FADEC engine can give similar performance with a skilled
operator, then what do you want to spend your pennies on.. a new fangled
electronically controlled engine? or keep using the old one with a few
extra knobs and dials.

Given that reasoning, cars should have the option of maintaining mixture
settings ourselves (if the EPA would allow it).

"Fred" wrote in message ...
Dave S wrote:
But if the non FADEC engine can give similar performance with a skilled
operator, then what do you want to spend your pennies on.. a new fangled
electronically controlled engine? or keep using the old one with a few
extra knobs and dials.

Given that reasoning, cars should have the option of maintaining mixture
settings ourselves (if the EPA would allow it).

First, in the application of automobiles, a manually-controlled mixture
*can't* give similar performance, as it can in an airplane. But even if it
could, there are lots of things about cars that are mandated by the
government, and which add cost to cars. So what? It doesn't in any way
invalidate the comment to which you're replying.

Mxsmanic wrote:
new_CFI writes:


its a fule to air ratio. x:y... so as you climb and air density
decreases the amount of fule require to keep the ratio constant,
changes. So, the amout of fuel you send to the engine needs to be less.
Thats where the mixture controll comes in. If you don't have the Pilots
Handbook of Aeronautical Knowledge, there is a good explanation of
it....if you don't have it; you can download it from the faa website.
If you need the link Ill post it, but I have to run….


I have the handbook. I pretty much understand the explanation, I just
wonder why the pilot adjusts it. You'd think that the engine would be
able to measure the static air pressure and adjust the mixture for
itself. Cars have complex engine computers, so why not aircraft
engines? Of course, if aircraft engines had the same unreliable
software that they put in cars, they'd drop out of the sky, so it
would have to be verified a lot more, and the engine would have to be
able to run without it.

Some do, but most don't. My last engine had a pressure carb on it and
the only thing we used the mixture for was to shut down. The new engine
does not have a pressure carb and it took a bit for me to remember to I
have to lean now!

Margy

Mxsmanic,

You'd think that the engine would be
able to measure the static air pressure and adjust the mixture for
itself.


Compare the productoin numbers of aircraft piston engines and car
engines. All of GA probably buys as many engines per year as Ford
installs in a day. The money for FAA-certified (!) innovation simply
isn't in it. Thus, we have engines that are, technologically speaking,
over 50 years old. Think fixed timing, magneto ignition, abysmal
efficiency, huge displacement. The only exception is the Thielert
diesel based on a modern car design, just coming to market with great
success.

--
Thomas Borchert (EDDH)

Thomas Borchert schrieb:

The only exception is the Thielert
diesel based on a modern car design, just coming to market with great
success.

Agreed, except that Thielert is not the only exception (e.g. Limbach
2400 DT1 being another example). But all those developments are pretty
recent and right now the installed base is a couple of hundred at most.

Stefan