Fuel tank balance

"Marty Shapiro" wrote in message
...
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.

Unfortunately (for the purpose of your example anyway, which is otherwise an
excellent one) most if not all modern cars use an air mass meter to ensure
correct fuel metering. High altitude driving doesn't require a carb
readjustment any more...the car's engine just compensates. Less power is
the only noticeable symptom, and I doubt most drivers are with-it enough to
notice that.

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?

Well, you could use the fuel cut-off valve, or you could short out the
p-leads to the magnetos, as alternatives to setting the mixture to the fuel
cut-off setting.

IMHO, the main reasons that aircraft engines require so much fiddling is
two-fold: one is that aircraft engines operate at constant settings for most
of the time they are on; another is that improvements cost big bucks in the
form of certification costs, bucks that most pilots won't pay when the
current (albeit ancient) technology suffices.

Pete

"Peter Duniho" wrote:
IMHO, the main reasons that aircraft engines require so much fiddling
is two-fold: one is that aircraft engines operate at constant settings
for most of the time they are on; another is that improvements cost
big bucks in the form of certification costs, bucks that most pilots
won't pay when the current (albeit ancient) technology suffices.

I believe FADEC (Full Authority Digital Engine Control)[1] systems are the
aviation equivalent of the automobile systems that automatically handle
mixture control. Aerosance[2] offers FADEC systems for ~$7k for FI piston
engines. I thought I read somewhere that someone building an experimental
was planning on installing a FADEC system and was going to whimsically use
the tortoise and hare (or is it turtle and rabbit?) symbols at the
throttle.

[1] http://en.wikipedia.org/wiki/FADEC
[2] http://www.fadec.com/index.asp

"Peter Duniho" wrote in
:

"Marty Shapiro" wrote in message
...
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.

Unfortunately (for the purpose of your example anyway, which is
otherwise an excellent one) most if not all modern cars use an air
mass meter to ensure correct fuel metering. High altitude driving
doesn't require a carb readjustment any more...the car's engine just
compensates. Less power is the only noticeable symptom, and I doubt
most drivers are with-it enough to notice that.


Not too noticeable until about 8,000'. Then it gets noticeable. Above
11,000' it gets very, very noticeable. Go to Pike's Peak and see what
happens!

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?

Well, you could use the fuel cut-off valve, or you could short out the
p-leads to the magnetos, as alternatives to setting the mixture to the
fuel cut-off setting.


I had to do that once in a C172. I pulled the mixture and the cable came
out in my hand. I turned the fuel to off with the engine at idle and it
took almost 6 1/2 minutes for the engine to stop.

IMHO, the main reasons that aircraft engines require so much fiddling
is two-fold: one is that aircraft engines operate at constant settings
for most of the time they are on; another is that improvements cost
big bucks in the form of certification costs, bucks that most pilots
won't pay when the current (albeit ancient) technology suffices.

Totally agree.


Pete




--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

Marty Shapiro writes:

Not too noticeable until about 8,000'. Then it gets noticeable. Above
11,000' it gets very, very noticeable. Go to Pike's Peak and see what
happens!

Yesterday I tried flying a Piper J-3 and a Cessna 172 over the top of
(I think) Mount Rainier (the tall mountain near KSEA), and they both
seemed to struggle as we approached the altitude of the peak. I
turned around and went back when it became obvious that I wasn't going
to make it. Not sure if it was engine power that lacked, or just air
density that was too low, or what. I was flying for fun and did not
check the altimeter.

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"Mxsmanic" wrote in message
...
Marty Shapiro writes:

Not too noticeable until about 8,000'. Then it gets noticeable. Above
11,000' it gets very, very noticeable. Go to Pike's Peak and see what
happens!

Yesterday I tried flying a Piper J-3 and a Cessna 172 over the top of
(I think) Mount Rainier (the tall mountain near KSEA), and they both
seemed to struggle as we approached the altitude of the peak. I
turned around and went back when it became obvious that I wasn't going
to make it. Not sure if it was engine power that lacked, or just air
density that was too low, or what. I was flying for fun and did not
check the altimeter.

--
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Yes, It is Mt. Rainier... It looked beautiful yesterday, even with the haze
that goes up to 2000', and could see it from Skagit Regional/Bayview (KBVS).
Went up there for lunch.

Reason you can't go over the top of Rainier in a 172 is the Service Ceiling
of a 172 is about 14,000 (some models are lower, some are slightly higher).,
the top of Mt. Rainier is 14,410 ft. I imagine the service ceiling for a
J-3 Cub would be lower than that of a 172.

Service Ceiling I believe is defined as "where Vx equals Vy", which where
they meet will result in a minimal to non-existent climb rate. Vx increases
as altitude increases, Vy decreases as altitude increases. Also as you
climb less dense air produces less lift (get to a point where there is not
longer "surplus" lift to produce a climb), and less engine power to move the
aircraft through the air. To climb a 172 to that altitude takes a long
time... :-) which is because as you climb the wings produce less and less
lift and the climb rate decreases, along with the engine not being able to
produce as much power. Yesterday, I flew up to KBVS from KRNT at 4500',
which I didn't reach until I was almost over KPAE, but then I had to hang
out at 2500' for a bit waiting for the Center Controller to get me a squawk
code and clear me through the Class B. :-) Coming home, I was telling my
passenger..."The question for the trip home is 5500' or 3500'?" And she
asked "Why?" I explained the VFR Altitude Rule, and then said "It takes a
'long time' to get to 5500' and then by the time you get there you pretty
much have to start descending, as it is easier to avoid the Class B."
Picked 3500' for the trip home, as that is sufficient to clear the Class D
at KPAE (Class D at KPAE goes to 3100') Route was basically
KRNT-KPAE-KBVS, KBVS-KPAE-KRNT

-Wade Hasbrouck
PP-ASEL
http://spaces.live.com/wadehas

Wade Hasbrouck writes:

Service Ceiling I believe is defined as "where Vx equals Vy", which where
they meet will result in a minimal to non-existent climb rate. Vx increases
as altitude increases, Vy decreases as altitude increases. Also as you
climb less dense air produces less lift (get to a point where there is not
longer "surplus" lift to produce a climb), and less engine power to move the
aircraft through the air. To climb a 172 to that altitude takes a long
time... :-) which is because as you climb the wings produce less and less
lift and the climb rate decreases, along with the engine not being able to
produce as much power.

Yup, that's what I noticed. At least it's a gradual thing, so it
doesn't come as a nasty surprise. It became obvious that the aircraft
didn't want to go higher, and as the slopes loomed in the window I
decided to turn around and explore other areas. The scenery for KSEA
and its surroundings is unusually detailed and performant, for some
reason.

Yesterday, I flew up to KBVS from KRNT at 4500',
which I didn't reach until I was almost over KPAE, but then I had to hang
out at 2500' for a bit waiting for the Center Controller to get me a squawk
code and clear me through the Class B. :-) Coming home, I was telling my
passenger..."The question for the trip home is 5500' or 3500'?" And she
asked "Why?" I explained the VFR Altitude Rule, and then said "It takes a
'long time' to get to 5500' and then by the time you get there you pretty
much have to start descending, as it is easier to avoid the Class B."
Picked 3500' for the trip home, as that is sufficient to clear the Class D
at KPAE (Class D at KPAE goes to 3100') Route was basically
KRNT-KPAE-KBVS, KBVS-KPAE-KRNT

In a sim I have the option of ignoring such things. Also, the ATC
simulation is pretty limited, so if you go outside what the sim
provides for, you have to pretend that ATC is talking to you, and I
don't have much imagination for that.

I'm trying to learn all the rules about airspace and ATC, but it's
complicated. And I don't have any charts, which makes it hard to
figure out where I am in terms of airspace in some cases. (You _can_
ask to transit Class B airspace in MSFS's ATC, but the clearance is
always granted unconditionally, so it's not very realistic.) The GPS
and other instruments do faithfully indicate changes in airspace, but
I'm not very good at watching for them.

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Mxsmanic wrote in
:

Marty Shapiro writes:

Not too noticeable until about 8,000'. Then it gets noticeable. Above
11,000' it gets very, very noticeable. Go to Pike's Peak and see what
happens!

Yesterday I tried flying a Piper J-3 and a Cessna 172 over the top of
(I think) Mount Rainier (the tall mountain near KSEA), and they both
seemed to struggle as we approached the altitude of the peak. I
turned around and went back when it became obvious that I wasn't going
to make it. Not sure if it was engine power that lacked, or just air
density that was too low, or what. I was flying for fun and did not
check the altimeter.


I was talking about modern automobiles with fuel injected engines and
electronic ingnition sensors which automatically adjust the fuel/air
mixture to compensate for altitude.

Mt. Rainier peak is 14,410' MSL, which, IIRC, is about 300' above the
service ceiling of a C-172N, but about 1,500' below the absolute ceiling.
Wikipedia states the Piper J-3 service ceiling is 11,500' MSL.

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

Mxsmanic wrote in
:

Marty Shapiro writes:

Not too noticeable until about 8,000'. Then it gets noticeable. Above
11,000' it gets very, very noticeable. Go to Pike's Peak and see what
happens!

Yesterday I tried flying a Piper J-3 and a Cessna 172 over the top of
(I think) Mount Rainier (the tall mountain near KSEA), and they both
seemed to struggle as we approached the altitude of the peak. I
turned around and went back when it became obvious that I wasn't going
to make it. Not sure if it was engine power that lacked, or just air
density that was too low, or what. I was flying for fun and did not
check the altimeter.

Does MSFS let you set whether you have oxygen in the plane?

Judah writes:

Does MSFS let you set whether you have oxygen in the plane?

The Baron 58 has a place for pilot oxygen, but apparently it's not
installed. In real life I would probably keep oxygen at hand on every
flight, irrespective of my planned cruising altitude.

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"Mxsmanic" wrote in message
...
Judah writes:

Does MSFS let you set whether you have oxygen in the plane?

The Baron 58 has a place for pilot oxygen, but apparently it's not
installed. In real life I would probably keep oxygen at hand on every
flight, irrespective of my planned cruising altitude.

Would you bring a parachute and life preserver too?