Fuel tank balance [Archive]

Roy Smith

September 23rd 06, 11:02 PM

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.

Marty Shapiro

September 24th 06, 12:04 AM

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)

Doug[_1_]

September 24th 06, 12:18 AM

Typically low wing aircraft "can't" have a "both" setting. Now there
are exceptions (if it has a header tank). So on low wing aircraft
(which HAVE to have fuel pump(s)), you typically have just left and
right. Now I am talking about small GA aircraft, not military or
transport aircraft.

If you have to have a fuel pump, then usually you have two, so you have
a backup if one quits.

As for the mixture, that is very important and often used. Most systems
now have an EGT (exhaust gas temp) guage and you use that temperature
to set the mixture. There is also a procedure for setting the mixture
based on rpm. At altitudes above 3000' (some use 5000), the mixture is
set leaner than full rich on the ground before takeoff at runup.

Mxsmanic

September 24th 06, 12:29 AM

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.

--
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Mxsmanic

September 24th 06, 12:45 AM

Doug writes:

> If you have to have a fuel pump, then usually you have two, so you have
> a backup if one quits.
>
> As for the mixture, that is very important and often used. Most systems
> now have an EGT (exhaust gas temp) guage and you use that temperature
> to set the mixture. There is also a procedure for setting the mixture
> based on rpm. At altitudes above 3000' (some use 5000), the mixture is
> set leaner than full rich on the ground before takeoff at runup.

How do I determine how much actual propulsive thrust I'm generating?
I see a throttle setting, manifold pressure, RPM, and pitch, but I'm
not sure how to set all this in order to increase or decrease total
thrust. I've been reading the FAA's handbook, but I'm still not very
clear on how it works. My _impression_ is that I advance throttles to
provide more power, and then set propeller pitch to the green range in
order to translate engine power into optimum thrust. Is that right?
But apparently manifold pressure is supposed to be telling me
something, too.

--
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Peter Duniho

September 24th 06, 01:00 AM

"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

Steve Foley[_2_]

September 24th 06, 01:07 AM

"Roy Smith" > wrote in message
...
> 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.
>

I switch every 1/2 hour, on the 1/2 hour. I burn from the left tank when the
minute hand is on the left side of the clock (30 - 59 minutes past the
hour), and the right tank when the minute hand is on the right side of the
clock (0 - 29 minutes past the hour). That way I can tell by looking if I
remembered to switch tanks.

The least I've ever landed with was 14 gallons (out of 50). That was 2 legs.

Doug[_1_]

September 24th 06, 01:14 AM

Piston engines use percent power. So if you want to cruise at 65% power
(and burn fuel at the rate stated for that power setting), you look in
the aircraft manual for the rpm setting and manifold setting that gives
65% power (there may be more than one). For any given percent power,
you will get better fuel economy if you use the lower rpm and higher
manifold pressure setting. (This is akin to going up a hill in a car in
a high gear and full throttle. Such procedure uses less fuel than
downshifting and using say, 3/4 throttle).

There is no percent power guage that gives a direct measure of the
engines output.

You can also derive percent power from fuel burn if you have an
accurate fuel flow meter. The rule of thumb is 12 horsepower per gallon
per hour. So if you are burning 12 gallons an hour that is 120
horsepower. If the engine's max horsepower is 180 then you are at
120/180 percent power.

Things like this give pilots on long flights something to do....

Thrust is something a little different. Airplanes with jet engines use
thrust (whose unit is pounds) for their power settings, I believe. I'm
no expert though. I do know you don't use thrust for small gasoline
driven prop engines like in Cessnas and Pipers.

new_CFI[_1_]

September 24th 06, 01:29 AM

well, for me, more often is easter to remember. And on those long flights,
its the only thing to do.... unless you have a ADF and can find a good AM
station.

Jim Logajan

September 24th 06, 01:31 AM

"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

Marty Shapiro

September 24th 06, 01:44 AM

"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)

new_CFI[_1_]

September 24th 06, 01:44 AM

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….

Newps

September 24th 06, 02:25 AM

Doug wrote:

>
> There is no percent power guage that gives a direct measure of the
> engines output.

Sure there is. JPI has one in their engine monitors. There are others.

Doug[_1_]

September 24th 06, 02:40 AM

I'd never heard of these, but, right you are! Check out
http://www.jpinstruments.com/edm_700.html
Quite the guage!

Newps wrote:
> Doug wrote:
>
> >
> > There is no percent power guage that gives a direct measure of the
> > engines output.
>
>
> Sure there is. JPI has one in their engine monitors. There are others.

Roy Smith

September 24th 06, 03:05 AM

In article >,
Newps > wrote:

> Doug wrote:
>
> >
> > There is no percent power guage that gives a direct measure of the
> > engines output.
>
>
> Sure there is. JPI has one in their engine monitors. There are others.

I suppose it depends on what you mean by "direct measure".

Power delivered by a rotating shaft is RPM * Torque. RPM is easy to
measure directly, torque is somewhat more difficult. In any case, the JPI
gizmo doesn't measure torque. It measures manifold pressure, and fuel
flow, and intake air temperature, and maybe a few other things, and
computes how much power the engine must be delivering based on those
inputs. That's not quite the same thing as measuring the output directly.

I'm not saying that what the JPI does isn't useful. Just that it doesn't
fit my definition of "direct measure".

Newps

September 24th 06, 03:37 AM

Roy Smith wrote:
> In article >,
> Newps > wrote:
>
>
>>Doug wrote:
>>
>>
>>>There is no percent power guage that gives a direct measure of the
>>>engines output.
>>
>>
>>Sure there is. JPI has one in their engine monitors. There are others.
>
>
> I suppose it depends on what you mean by "direct measure".
>
> Power delivered by a rotating shaft is RPM * Torque. RPM is easy to
> measure directly, torque is somewhat more difficult. In any case, the JPI
> gizmo doesn't measure torque. It measures manifold pressure, and fuel
> flow, and intake air temperature, and maybe a few other things, and
> computes how much power the engine must be delivering based on those
> inputs. That's not quite the same thing as measuring the output directly.
>
> I'm not saying that what the JPI does isn't useful. Just that it doesn't
> fit my definition of "direct measure".

As long as it's accurate, who cares?

Dan Luke

September 24th 06, 04:26 AM

"Newps" wrote:
>>
>> I'm not saying that what the JPI does isn't useful. Just that it doesn't
>> fit my definition of "direct measure".
>
>
>
>
> As long as it's accurate, who cares?

I would not accept as accurate a calculation that leaves out essential
parameters. It's an educated guess.

--
Dan
C172RG at BFM

BTIZ

September 24th 06, 04:28 AM

with 4 main body tanks fore to aft
2 wing tanks (1 each wing)
2 Main tanks 1 each side over each nacelle of 2 engines each (4 engines)
and 1 weapons bay tank added, #20,000# apprx
other two weapons bays carry 54, 500# gravity weapons
Total full up fuel load, apx 210,000#, aircraft weight, apx 200,000#,
weapons, 27,000# plus racks (4,000#) Take off weight, apx 441,000#, Max GW
for take off 477,000#

-Starting with full fuel all tanks, all tanks feed to the Mains.. keep the
mains above 10,000 #
-Burn from tanks 1 and 4 first (apx 18,000pph at this weight)
-Trap 35,000# fuel between the body tanks number 1 and 4 tanks for CG
control later in the flight
-Move 35,000# trapped fuel between tanks 1 and 4 to maintain CG when wings
sweep
-Burn off body tanks 2 and 3
-Burn off the weapons bay tank
-Burn off the wing (if fuel imbalance in wings we can cross feed, more than
10,000# fuel imbalance will cause roll control problems) may have to cross
feed if one or more engines on the same side are shut down
-Now down to 10,000# in each main and 35,000# in tanks 1 and 4 (total
55,000#)
-You best be at the IAF for the primary airport, 55,000 is enough to weather
divert to the approved alternate (apx 13,000pph fuel flow) and land with apx
20,000-25,000# in the tanks..

-Fuel slosh.. 20,000# is just 10,000# in each main tank, direct feed to the
engines
-Not enough weight forward to keep nose wheel steering squat switch engaged
for ground taxi,
you need to be above 7,000# each tank to start the approach

BT

"Mxsmanic" > wrote in message
...
> 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.

Jim Macklin

September 24th 06, 04:51 AM

The PT6 engine measures torque, which is shown in ft.lbs,
although the higher rated engines often use percent.

Measuring torque cost money, it isn't "cost effective" on
low powered engines.

"Roy Smith" > wrote in message
...
| In article >,
| Newps > wrote:
|
| > Doug wrote:
| >
| > >
| > > There is no percent power guage that gives a direct
measure of the
| > > engines output.
| >
| >
| > Sure there is. JPI has one in their engine monitors.
There are others.
|
| I suppose it depends on what you mean by "direct measure".
|
| Power delivered by a rotating shaft is RPM * Torque. RPM
is easy to
| measure directly, torque is somewhat more difficult. In
any case, the JPI
| gizmo doesn't measure torque. It measures manifold
pressure, and fuel
| flow, and intake air temperature, and maybe a few other
things, and
| computes how much power the engine must be delivering
based on those
| inputs. That's not quite the same thing as measuring the
output directly.
|
| I'm not saying that what the JPI does isn't useful. Just
that it doesn't
| fit my definition of "direct measure".

Newps

September 24th 06, 05:00 AM

Dan Luke wrote:
> "Newps" wrote:
>
>>>I'm not saying that what the JPI does isn't useful. Just that it doesn't
>>>fit my definition of "direct measure".
>>
>>
>>
>>
>>As long as it's accurate, who cares?
>
>
> I would not accept as accurate a calculation that leaves out essential
> parameters. It's an educated guess.

No, it's either accurate or it's not. Compare what the JPI says to what
the chart in the POH says. If it's accurate then it is irrelavant how
it got the information.

Robert M. Gary

September 24th 06, 05:18 AM

Mxsmanic wrote:
> Robert M. Gary writes:
> 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.

If you ran all your gas out of one tank you would only have 1/2 the
capacity. I switch tanks every hour.
-Robert

Robert M. Gary

September 24th 06, 05:24 AM

Mxsmanic wrote:
> Doug writes:

> How do I determine how much actual propulsive thrust I'm generating?
> I see a throttle setting, manifold pressure, RPM, and pitch, but I'm
> not sure how to set all this in order to increase or decrease total
> thrust.

Set power using throttle to the appropriate setting on your manifold
pressure. If you fly around full throttle down low you'll over stress
your engine. At cruise you usually leave the throttle full forward
(unless you have turbo charged).
You can't set the propeller pitch but you can adjust the propeller RPM.
Higher RPMs are good for higher power but for cruise you want something
less. Your POH will show you a manifold pressure(throttle)/RPM (prop
control) combo for the power setting you are looking for. We usually
refer to it as say 23/25 (meaning 23" manifold pressure, 2500 RPM).

Dumping extra fuel into the cylinders is good when climbing but not so
good during cruise. In cruise we lean the plane out for a more optimal
mixture. You car does the same. For the same RPM your car will set a
higher mixture during acceleration vs. in freeway driving. Most planes
have a EGT (exhaust temp ) to measure mixture, but you can do it just
by sound in a more basic plane.
Planes don't do this all at once for the same reason I have to shift my
car, because they don't use an automatic system. There are such systems
out there for planes but they are very expensive since it would be very
bad if it didn't work correctly.
-robert

Peter Duniho

September 24th 06, 05:24 AM

"Newps" > wrote in message
...
> [...]
>> I'm not saying that what the JPI does isn't useful. Just that it doesn't
>> fit my definition of "direct measure".
>
> As long as it's accurate, who cares?

It's only accurate when the engine is performing according to its design.

So I'd say any pilot using that sort of "power monitor" should care. It's
not a means for verifying actual power output of the engine. It's little
more than an electronic handbook translating the POH power charts to a
graphic real-time display.

Which is not to say it's not useful. I'd say it certainly is. But it's
VERY important to understand what it is and what it's not. Any pilot who
doesn't care is likely to wind up in the trees one day, trusting the display
too much.

Pete

Roger (K8RI)

September 24th 06, 07:21 AM

On Sat, 23 Sep 2006 17:32:11 +0200, 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.

Low wing aircraft generally have a set sequence or sequences of
drawing fuel from specific tanks to keep the plane balanced. If I
burn too much off one side (and it doesn't take a lot) the Deb will
get decidedly lop sided. A half hour to 45 minutes per side on the
mains is good. An hour on one side and the other wing will get heavy.
Were I to burn all the gas out of one wing tip tank while the other
was full I'd be in a heap of hurt and I'd want to get the major
portion out of the second tank before landing. The book says no more
than 5 gallons difference between the two.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Mxsmanic

September 24th 06, 10:24 AM

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 runâ€¦.

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.

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Mxsmanic

September 24th 06, 10:25 AM

Peter Duniho writes:

> 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 suppose that makes sense. I know that I'd rather have older
technology that is certified than newfangled technology that isn't, at
least for aviation (and for many other things, but I guess I'm getting
tired of seeing complex, poorly designed systems fail so often).

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Mxsmanic

September 24th 06, 10:28 AM

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

September 24th 06, 10:32 AM

Doug writes:

> Things like this give pilots on long flights something to do....

Do you mean to imply that it's not essential? I can't imagine pouring
over paper charts with a calculator on a final approach, just to see
what engine settings to use.

If I do nothing, do I lose only efficiency, or is there a safety issue
involved if I don't play with mixture or propeller pitch?

> Thrust is something a little different. Airplanes with jet engines use
> thrust (whose unit is pounds) for their power settings, I believe. I'm
> no expert though. I do know you don't use thrust for small gasoline
> driven prop engines like in Cessnas and Pipers.

I presume they just call it something different, but ultimately
powerplants push air somewhere to make the plane go.

I will try playing around with pitch and mixture and see what happens.

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Mxsmanic

September 24th 06, 10:37 AM

Robert M. Gary writes:

> Set power using throttle to the appropriate setting on your manifold
> pressure. If you fly around full throttle down low you'll over stress
> your engine. At cruise you usually leave the throttle full forward
> (unless you have turbo charged).

How do I know when the engine is potentially being stressed based on
the instruments? Low manifold pressure?

> You can't set the propeller pitch but you can adjust the propeller RPM.

On the A36 and B58 I've been trying to fly, there's a lever that says
pitch next to the throttle, and it has a feather setting (which I have
never used), so I presume it's pitch of the propeller blades.

> Dumping extra fuel into the cylinders is good when climbing but not so
> good during cruise. In cruise we lean the plane out for a more optimal
> mixture.

Is that just for reasons of economy, or does a rich mixture damage
something in the engine?

> You car does the same. For the same RPM your car will set a
> higher mixture during acceleration vs. in freeway driving. Most planes
> have a EGT (exhaust temp ) to measure mixture, but you can do it just
> by sound in a more basic plane.

Higher EGT = rich mixture?

> Planes don't do this all at once for the same reason I have to shift my
> car, because they don't use an automatic system. There are such systems
> out there for planes but they are very expensive since it would be very
> bad if it didn't work correctly.

Understood. My main concern is whether or not I'll get into trouble
if I fail to do all the tweaking of engine parameters while flying.

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

Mxsmanic

September 24th 06, 10:41 AM

Roger (K8RI) writes:

> Low wing aircraft generally have a set sequence or sequences of
> drawing fuel from specific tanks to keep the plane balanced. If I
> burn too much off one side (and it doesn't take a lot) the Deb will
> get decidedly lop sided. A half hour to 45 minutes per side on the
> mains is good. An hour on one side and the other wing will get heavy.
> Were I to burn all the gas out of one wing tip tank while the other
> was full I'd be in a heap of hurt and I'd want to get the major
> portion out of the second tank before landing. The book says no more
> than 5 gallons difference between the two.

That's what puzzles me: If you're not supposed to have a significant
difference between the two, why aren't the two tanks just connected so
that they always drain at the same rate on both sides? Why would you
_want_ one wing substantially heavier than the other?

I can see why one might want to change things for fore and aft tanks,
or between center tanks and wing tanks, but I don't see any utility to
having one wing heavier than the other, or to having wing tanks that
don't communicate with each other (provided there's a cutoff for
emergencies).

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

Dan Luke

September 24th 06, 01:25 PM

"Newps" wrote:

>>>As long as it's accurate, who cares?
>>
>>
>> I would not accept as accurate a calculation that leaves out essential
>> parameters. It's an educated guess.
>
> No, it's either accurate or it's not. Compare what the JPI says to what
> the chart in the POH says. If it's accurate then it is irrelavant how it
> got the information.

So pencil-whipped data agrees with pencil-whipped data. So what? It still
doesn't really tell you the actual power output because there's no way for
it to know the load the prop is putting on the engine.

If the prop controller has to flatten the pitch to make the specified RPM
because the engine is not making rated HP, the JPI will never know the
difference.

--
Dan
C172RG at BFM

Steve Foley[_2_]

September 24th 06, 01:54 PM

"Mxsmanic" > wrote in message
...

> That's what puzzles me: If you're not supposed to have a significant
> difference between the two, why aren't the two tanks just connected so
> that they always drain at the same rate on both sides?

On a low win airplane, you need a fuel pump to get the fuel to the engine.
If you have one fuel pump connected to both tanks, and one tank runs dry,
the fuel pump will be sucking only air, and no fuel from the other tank.

If you put in two fuel pumps, and one tank runs dry, you will probably burn
out the fuel pump running it dry.

If you put in a way for the pump to shut down when it's dry, you run the
risk of a faulire that shuts down the pump when there is still fuel in the
tank.

The goal is relable and simple. One fuel pump (actually, mine has an engine
driven pump and an electric backup pump), and a valve to select tanks.

> Why would you
> _want_ one wing substantially heavier than the other?

When I fly alone, the left side of the plane is heavier. If I burn fuel from
the left tank, after about an hour the plane is more balanced.

Steve Foley[_2_]

September 24th 06, 01:58 PM

"Steve Foley" > wrote in message
...
"Mxsmanic" > wrote in message
...

> That's what puzzles me: If you're not supposed to have a significant
> difference between the two, why aren't the two tanks just connected so
> that they always drain at the same rate on both sides?

On a low wing airplane, you need a fuel pump to get the fuel to the engine.
If you have one fuel pump connected to both tanks, and one tank runs dry,
the fuel pump will be sucking only air, and no fuel from the other tank.

If you put in two fuel pumps, and one tank runs dry, you will probably burn
out the fuel pump running it dry.

If you put in a way for the pump to shut down when it's dry, you run the
risk of a faulire that shuts down the pump when there is still fuel in the
tank.

The goal is relable and simple. One fuel pump (actually, mine has an engine
driven pump and an electric backup pump), and a valve to select tanks.

> Why would you
> _want_ one wing substantially heavier than the other?

When I fly alone, the left side of the plane is heavier. If I burn fuel
from
the left tank, after about an hour the plane is more balanced.

The Visitor

September 24th 06, 03:43 PM

Mxsmanic wrote:
why aren't the two tanks just connected so
> that they always drain at the same rate on both sides?

Also keep in mind the need to isolate a fuel leak.

Thomas Borchert

September 24th 06, 04:36 PM

Steve,

> when the
> minute hand
>

What'S that? ;-)

Otherwise, nice trick.

--
Thomas Borchert (EDDH)

Steve Foley[_2_]

September 24th 06, 04:39 PM

"Thomas Borchert" > wrote in message
...
> Steve,
>
>> when the
>> minute hand
>>
>
> What'S that? ;-)
>

That's the thing I forget to wind prior to each flight <g>

Wade Hasbrouck

September 24th 06, 06:18 PM

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

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

Marty Shapiro

September 24th 06, 06:21 PM

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)

Wade Hasbrouck

September 24th 06, 06:38 PM

"Mxsmanic" > wrote in message
...
> Robert M. Gary writes:
>
>> Set power using throttle to the appropriate setting on your manifold
>> pressure. If you fly around full throttle down low you'll over stress
>> your engine. At cruise you usually leave the throttle full forward
>> (unless you have turbo charged).
>
> How do I know when the engine is potentially being stressed based on
> the instruments? Low manifold pressure?
>
>> You can't set the propeller pitch but you can adjust the propeller RPM.
>
> On the A36 and B58 I've been trying to fly, there's a lever that says
> pitch next to the throttle, and it has a feather setting (which I have
> never used), so I presume it's pitch of the propeller blades.
>
>> Dumping extra fuel into the cylinders is good when climbing but not so
>> good during cruise. In cruise we lean the plane out for a more optimal
>> mixture.
>
> Is that just for reasons of economy, or does a rich mixture damage
> something in the engine?

Rich Mixture will not typically damage the engine... however running an
engine too lean can, because if you lean too much the cylinder head
temperatures will be higher than normal and can cause detonation. Running
too rich can cause the plugs to foul. Also if you don't lean as you climb,
you will lose power because the engine is running to rich.

>
>> You car does the same. For the same RPM your car will set a
>> higher mixture during acceleration vs. in freeway driving. Most planes
>> have a EGT (exhaust temp ) to measure mixture, but you can do it just
>> by sound in a more basic plane.
>
> Higher EGT = rich mixture?

No... Higher EGT indicates leaner mixture. Excess fuel in the cylinder has
a cooling effect. Leaning procedure in many planes is to lean to peak EGT
and then richen to 25 - 50 degrees of peak EGT, if there is an EGT guage.
Plane I flew yesterday, does not have an EGT... So you lean for Max RPM and
then richen slightly for smooth operation, and this was for a 1976 Cessna
172M.

>
>> Planes don't do this all at once for the same reason I have to shift my
>> car, because they don't use an automatic system. There are such systems
>> out there for planes but they are very expensive since it would be very
>> bad if it didn't work correctly.
>
> Understood. My main concern is whether or not I'll get into trouble
> if I fail to do all the tweaking of engine parameters while flying.
>

Depends on your definition of "trouble"... Running an engine full rich at
7000' and then trying to climb at a certain rate to clear an obstacle... You
may not have the power you need to climb and clear the obstacle, and think
that could qualify as "trouble"

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

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

Wade Hasbrouck

September 24th 06, 07:13 PM

"B A R R Y" > wrote in message
...
> On Sun, 24 Sep 2006 10:18:34 -0700, "Wade Hasbrouck"
> > wrote:
>>
>>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
>
> I always thought it was where the plane was no longer capable of
> climbing at a rate greater than 100 ft/min.
>

You are correct... I should look at Wikipedia before typing... :-)

"From Wikipedia, the free encyclopedia

In aeronautics, the service ceiling is the density altitude where the flying
in a clean configuration, at the best rate of climb airspeed for that
altitude, and with all engines operating and producing maximum continuous
power will produce a 100 feet per minute climb. Margin to stall at service
ceiling is 1.5g."

Will have to go back to the reference book that talked about the point where
Vx and Vy are equal and see what they called that... :-)

Thomas Borchert

September 24th 06, 07:19 PM

Wade,

> however running an
> engine too lean can, because if you lean too much the cylinder head
> temperatures will be higher than normal and can cause detonation.

...

> No... Higher EGT indicates leaner mixture. Excess fuel in the cylinder has
> a cooling effect.

Sorry, but you're wrong. Running not lean enough can cause detonation. Or,
more exactly: Putting the mixture in the wrong place can. Cylinder pressures
are highest at about 50 to 75 rich of peak. Higher EGT does indicate closeness
to peak EGT, but not a leaner mixture. The leaner the mixture, the cooler the
EGT - once you're beyond peak.

The misconceptions behind your statements lead to people not liking to
contemplate LOP operations, which is why I point them out.

--
Thomas Borchert (EDDH)

Mark Hansen

September 24th 06, 07:27 PM

On 09/24/06 11:13, Wade Hasbrouck wrote:
> "B A R R Y" > wrote in message
> ...
>> On Sun, 24 Sep 2006 10:18:34 -0700, "Wade Hasbrouck"
>> > wrote:
>>>
>>>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
>>
>> I always thought it was where the plane was no longer capable of
>> climbing at a rate greater than 100 ft/min.
>>
>
> You are correct... I should look at Wikipedia before typing... :-)
>
> "From Wikipedia, the free encyclopedia
>
> In aeronautics, the service ceiling is the density altitude where the flying
> in a clean configuration, at the best rate of climb airspeed for that
> altitude, and with all engines operating and producing maximum continuous
> power will produce a 100 feet per minute climb. Margin to stall at service
> ceiling is 1.5g."
>
> Will have to go back to the reference book that talked about the point where
> Vx and Vy are equal and see what they called that... :-)
>

It the airplane's absolute ceiling.

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

Wade Hasbrouck

September 24th 06, 07:39 PM

"Mark Hansen" > wrote in message
...
> On 09/24/06 11:13, Wade Hasbrouck wrote:
>> "B A R R Y" > wrote in message
>> ...
>>> On Sun, 24 Sep 2006 10:18:34 -0700, "Wade Hasbrouck"
>>> > wrote:
>>>>
>>>>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
>>>
>>> I always thought it was where the plane was no longer capable of
>>> climbing at a rate greater than 100 ft/min.
>>>
>>
>> You are correct... I should look at Wikipedia before typing... :-)
>>
>> "From Wikipedia, the free encyclopedia
>>
>> In aeronautics, the service ceiling is the density altitude where the
>> flying
>> in a clean configuration, at the best rate of climb airspeed for that
>> altitude, and with all engines operating and producing maximum continuous
>> power will produce a 100 feet per minute climb. Margin to stall at
>> service
>> ceiling is 1.5g."
>>
>> Will have to go back to the reference book that talked about the point
>> where
>> Vx and Vy are equal and see what they called that... :-)
>>
>
> It the airplane's absolute ceiling.
>

I was going to say that... But figured I would go look it up before "opening
my mouth" again... :-)

>
> --
> Mark Hansen, PP-ASEL, Instrument Airplane
> Cal Aggie Flying Farmers
> Sacramento, CA

Wade Hasbrouck

September 24th 06, 08:07 PM

"Thomas Borchert" > wrote in message
...
> Wade,
>
>> however running an
>> engine too lean can, because if you lean too much the cylinder head
>> temperatures will be higher than normal and can cause detonation.
>
> ..
>
>> No... Higher EGT indicates leaner mixture. Excess fuel in the cylinder
>> has
>> a cooling effect.
>
> Sorry, but you're wrong. Running not lean enough can cause detonation. Or,
> more exactly: Putting the mixture in the wrong place can. Cylinder
> pressures
> are highest at about 50 to 75 rich of peak. Higher EGT does indicate
> closeness
> to peak EGT, but not a leaner mixture. The leaner the mixture, the cooler
> the
> EGT - once you're beyond peak.
>
> The misconceptions behind your statements lead to people not liking to
> contemplate LOP operations, which is why I point them out.
>
>
> --
> Thomas Borchert (EDDH)
>

What is "LOP operations"?

I realize I got the leaning procedure for EGT wrong... As yes, you lean
until it peaks and then goes down by 25 - 50 (or what ever the POH says).
Plane I currently fly does not have an EGT and was going by what I have
read... Was taught "Lean to max RPM then richen slightly..."

I am confused now... Are you saying "running full rich" can cause
detonation? As this caused me to go look in my copy of Rod Machado's
Private Pilot Handbook to see what the causes of detonation are and he lists
the following as "several know causes of detonation"

1. Using a lower grade of fule than what is recommended by the
manufacturer. Higher octoane fuels have additives which help prevent
detonation.

2. Using time-expired fuel.

3. Over-leaning. Excessive leaning can raise cylinder head temperatures
increasing the likelihood of fuel exploding insteadd of burning within the
cylinders.

4. Overheating and engine by climbing too steeply on hotdays, as waell as
using excessive engine power (some engines have restriction on the time
maximum power can be used).

5. An abrupt opening of the throttle.

In the section "Too Rich and Too Lean" he talks about what happens if it is
too rich or too lean. The following are quotes from that section.

"Aside from inefficient fuel combustion, mixtures that are too rich or too
lean cause difficulties with engine operation. A mixture that is too rich
causes engine roughness. Spark plugs are easily fouled when unburned fuel
residue builds up between the plug gap..... "

"It's interesting to note that a fouled spark plug in flight can be detected
by an increase in EGT. Why? With only one flame source operating with the
cylinder, it takes longer to reach the maximum combustion temperature of the
cylinder's fuel-charge (it simply burns slower). As a result, the mixture
is hotter as it exits the exhaust valve, resulting in a higher EGT."

"Aside from a rough running engine, an excessively rich mixture contributes
to high fuel consumption...."

"A mixture that 's too lean produces other problems. First, too lean a
mixture means liss power is produced...."

"The biggest danger with an excessively lean mixture is that it burns hot.
It does so because it burns slower. This exposes the cylinder, postion and
valves to higher temperatures and high temperature is the worst enemy of
metal, causes reduced cylinder life and other problems..."

"High cylinder tempreatures also lead to something know as detonation.
Instead of a smoth even expansion of the fuel-air charge within the
cylinder, the mixture detonates (explodes), causing damage to the
engine...."

And there is even a question on the private pilot knowledge exam that asks
what to do if you have an overheating engine or detonation... and I believe
the the answer is "richen the mixture."

Mark Hansen

September 24th 06, 09:48 PM

On 09/24/06 11:39, Wade Hasbrouck wrote:
> "Mark Hansen" > wrote in message
> ...
>> On 09/24/06 11:13, Wade Hasbrouck wrote:
>>> "B A R R Y" > wrote in message
>>> ...
>>>> On Sun, 24 Sep 2006 10:18:34 -0700, "Wade Hasbrouck"
>>>> > wrote:
>>>>>
>>>>>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
>>>>
>>>> I always thought it was where the plane was no longer capable of
>>>> climbing at a rate greater than 100 ft/min.
>>>>
>>>
>>> You are correct... I should look at Wikipedia before typing... :-)
>>>
>>> "From Wikipedia, the free encyclopedia
>>>
>>> In aeronautics, the service ceiling is the density altitude where the
>>> flying
>>> in a clean configuration, at the best rate of climb airspeed for that
>>> altitude, and with all engines operating and producing maximum continuous
>>> power will produce a 100 feet per minute climb. Margin to stall at
>>> service
>>> ceiling is 1.5g."
>>>
>>> Will have to go back to the reference book that talked about the point
>>> where
>>> Vx and Vy are equal and see what they called that... :-)
>>>
>>
>> It the airplane's absolute ceiling.
>>
>
> I was going to say that... But figured I would go look it up before "opening
> my mouth" again... :-)

Hey ... this is Usenet! ;-)

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

Judah

September 24th 06, 09:49 PM

Mark Hansen

September 24th 06, 09:54 PM

On 09/24/06 12:07, Wade Hasbrouck wrote:
> "Thomas Borchert" > wrote in message
> ...
>> Wade,
>>
>>> however running an
>>> engine too lean can, because if you lean too much the cylinder head
>>> temperatures will be higher than normal and can cause detonation.
>>
>> ..
>>
>>> No... Higher EGT indicates leaner mixture. Excess fuel in the cylinder
>>> has
>>> a cooling effect.
>>
>> Sorry, but you're wrong. Running not lean enough can cause detonation. Or,
>> more exactly: Putting the mixture in the wrong place can. Cylinder
>> pressures
>> are highest at about 50 to 75 rich of peak. Higher EGT does indicate
>> closeness
>> to peak EGT, but not a leaner mixture. The leaner the mixture, the cooler
>> the
>> EGT - once you're beyond peak.
>>
>> The misconceptions behind your statements lead to people not liking to
>> contemplate LOP operations, which is why I point them out.
>>
>>
>> --
>> Thomas Borchert (EDDH)
>>
>
> What is "LOP operations"?

Let me give you a pointer to a great deal of engine operational information.
John Deakin has written a series of articles for AVWeb. The series is
called Pelican's Perch. You can see the index of his engine-related articles
here:

<http://www.avweb.com/news/pelican/182544-1.html>

They make a very good read. You need to be a member, but the membership
is free. If you're not familiar with AVWeb, there are lots of great
resources there, including lots of other regular columns like John's.

>
> I realize I got the leaning procedure for EGT wrong... As yes, you lean
> until it peaks and then goes down by 25 - 50 (or what ever the POH says).
> Plane I currently fly does not have an EGT and was going by what I have
> read... Was taught "Lean to max RPM then richen slightly..."
>
> I am confused now... Are you saying "running full rich" can cause
> detonation? As this caused me to go look in my copy of Rod Machado's
> Private Pilot Handbook to see what the causes of detonation are and he lists
> the following as "several know causes of detonation"
>
> 1. Using a lower grade of fule than what is recommended by the
> manufacturer. Higher octoane fuels have additives which help prevent
> detonation.
>
> 2. Using time-expired fuel.
>
> 3. Over-leaning. Excessive leaning can raise cylinder head temperatures
> increasing the likelihood of fuel exploding insteadd of burning within the
> cylinders.
>
> 4. Overheating and engine by climbing too steeply on hotdays, as waell as
> using excessive engine power (some engines have restriction on the time
> maximum power can be used).
>
> 5. An abrupt opening of the throttle.
>
> In the section "Too Rich and Too Lean" he talks about what happens if it is
> too rich or too lean. The following are quotes from that section.
>
> "Aside from inefficient fuel combustion, mixtures that are too rich or too
> lean cause difficulties with engine operation. A mixture that is too rich
> causes engine roughness. Spark plugs are easily fouled when unburned fuel
> residue builds up between the plug gap..... "
>
> "It's interesting to note that a fouled spark plug in flight can be detected
> by an increase in EGT. Why? With only one flame source operating with the
> cylinder, it takes longer to reach the maximum combustion temperature of the
> cylinder's fuel-charge (it simply burns slower). As a result, the mixture
> is hotter as it exits the exhaust valve, resulting in a higher EGT."
>
> "Aside from a rough running engine, an excessively rich mixture contributes
> to high fuel consumption...."
>
> "A mixture that 's too lean produces other problems. First, too lean a
> mixture means liss power is produced...."
>
> "The biggest danger with an excessively lean mixture is that it burns hot.
> It does so because it burns slower. This exposes the cylinder, postion and
> valves to higher temperatures and high temperature is the worst enemy of
> metal, causes reduced cylinder life and other problems..."
>
> "High cylinder tempreatures also lead to something know as detonation.
> Instead of a smoth even expansion of the fuel-air charge within the
> cylinder, the mixture detonates (explodes), causing damage to the
> engine...."
>
> And there is even a question on the private pilot knowledge exam that asks
> what to do if you have an overheating engine or detonation... and I believe
> the the answer is "richen the mixture."
>

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

Dave S

September 24th 06, 11:57 PM

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.

Margy Natalie

September 25th 06, 12:43 AM

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 runâ€¦.
>
>
> 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

Wade Hasbrouck

September 25th 06, 02:57 AM

>> What is "LOP operations"?
>
> Let me give you a pointer to a great deal of engine operational
> information.
> John Deakin has written a series of articles for AVWeb. The series is
> called Pelican's Perch. You can see the index of his engine-related
> articles
> here:
>
> <http://www.avweb.com/news/pelican/182544-1.html>
>
> They make a very good read. You need to be a member, but the membership
> is free. If you're not familiar with AVWeb, there are lots of great
> resources there, including lots of other regular columns like John's.
>
>

Thanks for the pointer to the site, I took a glance at the site... Looks
quite good. I appreciate this.

>
>
> --
> Mark Hansen, PP-ASEL, Instrument Airplane
> Cal Aggie Flying Farmers
> Sacramento, CA

Fred

September 25th 06, 05:19 AM

Marty Shapiro wrote:

> 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.

Yes, except I've gone far higher than 5,000' MSL. Take a morning drive from
any (sea level) beach in Maui, for example to the summit of Mt Haleakala
(10,000+ ft). And the 'pilot' of the car doesn't have to do a damn thing for
the mixture, the injector pulse width (aka the mixture) is adjusted by the
computer automatically for max performance of power/emissions. Pretty basic
stuff for any car today, too bad so many aircraft are still using 1930s era
design engines.

Fred

September 25th 06, 05:21 AM

Marty Shapiro wrote:

> 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.

Yes, doens't that remind you of a basic lawn mower engine?

> You can
> have total electrical failure and the engine will keep on running.

They may not be connected to the battery or alternator, but those magnetos are
an "electrical system" all of their own, and the engine will not keep running
if they have an electrical failure.

> How do you stop the engine after you land?

Disconnecting the magnetos (or actually just grounding their output) stops the
engine pretty well. No need for a mixture control. (Of course if you want to
restart that engine without blowing away the exhaust......)

Fred

September 25th 06, 05:23 AM

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).

Peter Duniho

September 25th 06, 05:38 AM

"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.

Emily[_1_]

September 25th 06, 06:14 AM

Fred wrote:
> Marty Shapiro wrote:
>
>> 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.
>
> Yes, doens't that remind you of a basic lawn mower engine?

Not really. Granted, I'm not a lawn mower engine expert, but I believe
they are two stroke engines, yes? Completely different than a four
stroke piston aircraft engine. Going farther, a turbine aircraft engine
generally doesn't stop once it starts running, and I'd hardly compare
*that* to a lawn mower engine.

Wade Hasbrouck

September 25th 06, 06:48 AM

"Fred" > wrote in message ...
> Marty Shapiro wrote:
>
>> 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.
>
> Yes, doens't that remind you of a basic lawn mower engine?

Actually it, reminds me more of the engine in my 1967 VW Bug (horizontally
opposed aircooled engine)... :-) It just doesn't use magnetos for the
ignition system. I have always kind of thought of the engine in the 172 I
fly as "just a bigger bug motor, and uses magnetos, and the mixture is
controllable while it is running..."

Mxsmanic

September 25th 06, 07:25 AM

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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Marty Shapiro

September 25th 06, 08:21 AM

Fred > wrote in :

>
>
> Marty Shapiro wrote:
>
>> 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.
>
> Yes, except I've gone far higher than 5,000' MSL. Take a morning
> drive from any (sea level) beach in Maui, for example to the summit of
> Mt Haleakala (10,000+ ft). And the 'pilot' of the car doesn't have to
> do a damn thing for the mixture, the injector pulse width (aka the
> mixture) is adjusted by the computer automatically for max performance
> of power/emissions. Pretty basic stuff for any car today, too bad so
> many aircraft are still using 1930s era design engines.
>
>

Try going a little higher, like to Pike's Peak, 14,110. You will find
a noticeable drop off in power. For extra fun, do it on a hot summer day
in a rental car with the a/c on and watch the "check engine" light come on
at about 12,000'.

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

Ron Natalie

September 25th 06, 01:29 PM

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.
>
Not all tanks can be used in all flight regimes. My tip tanks
can not be used for takeoff or landing (well I don't think they
will make a difference on landing, but you want to be able to
do a go-around don't you). Also, the injected fuel system
returns fuel back to the main tank alone in my system, so
you don't start using the aux tanks until you have sufficient
headroom in the mains.

Ron Natalie

September 25th 06, 01:30 PM

new_CFI wrote:

>
> as far as left/right/both/off, normaly you set it on both and forget it.

Even Cessna recommends using Left or Right at high altitude cruise to
alleviate vapor locking problems. Of course, which tank level is
going down on a 172 is only marginally related to the selector
position.

Mxsmanic

September 25th 06, 03:05 PM

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

September 25th 06, 03:07 PM

Marty Shapiro writes:

> Try going a little higher, like to Pike's Peak, 14,110. You will find
> a noticeable drop off in power.

But the engine will still be automatically optimized for peak power,
whereas an aircraft engine will not. I think that's the point.

Also, human beings tend to start losing power at 14,000 feet, too.

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Steve Foley[_1_]

September 25th 06, 03:39 PM

"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?

Marty Shapiro

September 25th 06, 06:49 PM

Mxsmanic > wrote in
:

> Marty Shapiro writes:
>
>> Try going a little higher, like to Pike's Peak, 14,110. You will find
>> a noticeable drop off in power.
>
> But the engine will still be automatically optimized for peak power,
> whereas an aircraft engine will not. I think that's the point.
>
> Also, human beings tend to start losing power at 14,000 feet, too.
>

Only if the fuel-air sensor was designed to handle that altitude.
Estimating from the performance I experienced, the limit seemed to be
somewhere between 11,000 and 12,000 feet.

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

Robert M. Gary

September 25th 06, 09:32 PM

Mxsmanic wrote:
> Robert M. Gary writes:
> How do I know when the engine is potentially being stressed based on
> the instruments? Low manifold pressure?

You use your POH book. If it says that 75% power at 10,000 feet
requires 22" of manifold pressure and 2400 RPM , that's what you run.
As a pilot you decide what power (percent) you want to run and how fast
you want to get there. From there the POH will give you some choices of
MP/RPM. Faster flying, quickly burns more fuel.

>
> > You can't set the propeller pitch but you can adjust the propeller RPM.
>
> On the A36 and B58 I've been trying to fly, there's a lever that says
> pitch next to the throttle, and it has a feather setting (which I have
> never used), so I presume it's pitch of the propeller blades.

Indirectly. The label is poor. The lever controls the RPM. The actualy
pitch is controlled automatically. You set the RPM you want, the plane
continuously adjusts the pitch to meet that. A typical training plane
would not have this control.

> Is that just for reasons of economy, or does a rich mixture damage
> something in the engine?

Leaning is also based on the power % you selected in the book.

> > You car does the same. For the same RPM your car will set a
> > higher mixture during acceleration vs. in freeway driving. Most planes
> > have a EGT (exhaust temp ) to measure mixture, but you can do it just
> > by sound in a more basic plane.
>
> Higher EGT = rich mixture?

Higher EGT = peak temperature. So we speak of mixture in terms of peak.
I might say "I run my plane 50 degrees rich of peak, but Bill runs his
25 lean of peak. Bob likes to run his at peak".

> Understood. My main concern is whether or not I'll get into trouble
> if I fail to do all the tweaking of engine parameters while flying.

This is really more of a sim question. In real life when you transition
a student to more complex aircraft (with all the controls you are
speaking of) you discuss operations. Its much easier to understand from
a practical point of view. You're approaching it academically which is
harder to understand, especially w/o sitting one-on-one with a CFI.

-Robert, CFI

Mxsmanic

September 25th 06, 10:13 PM

Steve Foley writes:

> Would you bring a parachute and life preserver too?

Parachuting requires special training and there probably wouldn't be
time to put the parachute on in an emergency.

A flotation device would definitely be nice over water, or even a raft
for an extended trip over water.

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Steve Foley[_2_]

September 25th 06, 10:18 PM

"Mxsmanic" > wrote in message
...
> Steve Foley writes:
>
>> Would you bring a parachute and life preserver too?
>
> Parachuting requires special training

Please cite the FAA regs.

Mxsmanic

September 25th 06, 10:42 PM

Steve Foley writes:

> Please cite the FAA regs.

It's not an FAA regulation, it's just a fact of using a parachute.
You don't just slip one on and jump.

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Steve Foley[_2_]

September 25th 06, 11:03 PM

"Mxsmanic" > wrote in message
...
> Steve Foley writes:
>
>> Please cite the FAA regs.
>
> It's not an FAA regulation, it's just a fact of using a parachute.
> You don't just slip one on and jump.

You do if the plane is on fire.

Margy Natalie

September 26th 06, 01:10 AM

Steve Foley wrote:
> "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?
>
>
We usually have the oxygen in the backseat even if we don't plan a high
flight. I don't think it has anything to do with being too lazy to put
it away :-)

Margy

Mxsmanic

September 26th 06, 06:29 AM

Steve Foley writes:

> You do if the plane is on fire.

You can jump without a parachute if the plane is on fire, too; the
results will be much the same, if you have no parachute training.

This is a key reason why parachutes are not present in civilian
aircraft. Most passengers don't have the training necessary to use
them.

--
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Thomas Borchert

September 26th 06, 11:39 AM

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

September 26th 06, 11:39 AM

Wade,

> What is "LOP operations"?

Lean of Peak = LOP

>
> I am confused now... Are you saying "running full rich" can cause
> detonation? As this caused me to go look in my copy of Rod Machado's

No, I'm not. Ron Machado isn't god. He isn't even funny, mostly.

I recommend the engine management columns by John Deakin at www.avweb.com. He
explains it much better than I ever could.

--
Thomas Borchert (EDDH)

Stefan

September 26th 06, 11:54 AM

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

Wade Hasbrouck

September 26th 06, 05:17 PM

"Thomas Borchert" > wrote in message
...
> Wade,
>
>> What is "LOP operations"?
>
> Lean of Peak = LOP
>
>>
>> I am confused now... Are you saying "running full rich" can cause
>> detonation? As this caused me to go look in my copy of Rod Machado's
>
> No, I'm not. Ron Machado isn't god. He isn't even funny, mostly.
>
> I recommend the engine management columns by John Deakin at www.avweb.com.
> He
> explains it much better than I ever could.
>
> --
> Thomas Borchert (EDDH)
>

Thanks for the Explanation of LOP... I appreciate it... I have been reading
the articles from the site that Mark pointed me to and found them a nice
resource, and something new to learn about.

If I made Rod out to be "god" that was not, that was not my intention... It
was just the book that I had available at the time, and felt it was a
sufficient reference... I just also looked in the Kershner book, and it says
pretty much the same thing as the Machado book. The Kershner book doesn't
mention anything about using EGT to lean.

As far as Rod being funny... That is purely personal taste. I enjoy his
humor, but I know others do not, and respect that, which is why when I put
the quotes from the book, I left the jokes out... :-)

But, I think Cessna is just as guilty of encouraging ROP operations as the
POH I have for a 1980 Cessna 172N says under "Cruise" procedure in Section
4, and POHs for the 172M that I fly says the same:

"To acheive the recommended lean mixture fuel consumption figures shown in
section 5, the mixture should be leaned until engine RPM peaks and drops
25-50 RPM. At lower powers it may be necessary to enrichen the mixture
slightly to obtain smooth operation."

"Should it be necessary to cruise at higher than 75% power, the mixture
should not be leaned more than is required to proved peak RPM."

Then under the subsection "Leaning with a Cessna Economy Mixture Indicator
(EGT):

"Exhaust gas temperature (EGT) as shown on the optional Cessna Economy
Mixture Indicator may be used as an aid for mixture leaning in crising
flight at 75% pwoer or less. To adjust the mixture using this indicator,
lean to establish the peak EGT as a reference point and then enrichen the
mixture by the desired increment based on figure 4-4."

Figure 4-4:
Mixture Description Exhaust Gas Temperature
Recommended Lean 50 degrees rich of Peak EGT
Best Economy Peak EGT

"Under some conditions, engine roughness may occur while operating at peak
EGT. In this case, operate at the Recommended Lean mixture. Any change in
altitude or thorttle position will require a recheck of EGT indication."

Before your post I had never heard of the term LOP operations, thus the
reason why I had asked what it was, as I had never heard of it. Most
everything that I have read, suggests ROP operation, with the exception of
Rod's book, which says when leaning via EGT it says to lean 25 - 50 degrees
LOP, which I admit I messed it up in my original post, as I probably had the
POH in my head, and since the plane I fly does not have an EGT (it was
optional 172s) I will admit that I don't do this on a regular basis.

So, I hope you can understand it was not my intent to discourage one
practice over another (I didn't really know about the one practice), I was
just giving the the information that I had at the time and the things that I
had learned from the books I have read.

Blue Skies,

Wade Hasbrouck

Thomas Borchert

September 27th 06, 06:06 PM

Mxsmanic,

> You can jump without a parachute if the plane is on fire, too; the
> results will be much the same, if you have no parachute training.

And again, you go on about something you are utterly clueless about.
You are wrong.

>
> This is a key reason why parachutes are not present in civilian
> aircraft. Most passengers don't have the training necessary to use
> them.

No, it is not. Parachutes are not present, because they aren't needed.
In gliders, the risk of a mid-air is much higher, so they are often
issued - to untrained passengers as well. Training consists of "pull
here". It's all that's needed.

--
Thomas Borchert (EDDH)

Roger (K8RI)

September 28th 06, 06:53 AM

On Mon, 25 Sep 2006 08:29:10 -0400, Ron Natalie >
wrote:

>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.
>>
>Not all tanks can be used in all flight regimes. My tip tanks
>can not be used for takeoff or landing (well I don't think they
>will make a difference on landing, but you want to be able to
>do a go-around don't you). Also, the injected fuel system
>returns fuel back to the main tank alone in my system, so
>you don't start using the aux tanks until you have sufficient
>headroom in the mains.

On the Deb the tip tanks are...well...just tanks. You have to pump
the contents of the tip tanks into the mains before you can use that
gas. Of course the mains need to have enough room to take that 15
gallons each. Typically I don't bother with the tip tanks as it takes
a good 3 hour plus trip to make them useful.

When transferring fuel I run both transfer pumps at the same time to
keep things in balance. The engine burns 14 GPH. The tip tanks
carry 15 gallons each and the transfer pumps will move all 15 gallons
in 45 minutes. Running an hour on one main will make the plane
decidedly lopsided. 45 minutes is stretching the balance comfort
factor. You do not really want to burn off 15 gallons out of both
mains as there is 11 gallons considered unusable and they are 25
gallon tanks. Just to complicate matters when running off the aux
tanks (10 gallon on each side) they return to the left main only.
About 30 to 40% of the fuel ( 6 to 8 gallons) is returned to that left
main. Oh, and it feeds from both aux tanks at the same time.

As you can see, keeping in balance, keeping at least one main with
useable fuel and not over filling when transferring from the tip
tanks, or over filling the left main when running off the Aux tanks
can make keeping track of how long you are feeding from where, when
can be vital.

If I switch mains at 1/2 hour intervals, turn on the transfer pumps at
2 hours (one hour on each main) I will stay balanced and not over fill
either main. That will also leave the left main down far enough to
take the return fuel from the aux tanks without over filling OR
getting out of balance IF I continue to follow the proper sequence of
feeding.

I carry about 4 1/4 hours of useable fuel between the mains and aux
tanks. I carry about 2 hours and 10 minutes worth in the tips.

In an emergency I could use *all* of that fuel considered unusable but
I'd not want to have to do a go around or any steep climbs and all
turns would need to be right on the ball for coordination. IOW
depending on those 11 gallons would not be smart at all.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Thomas Borchert

September 28th 06, 11:23 AM

Wade,

Learning is what this is all about, so I'm glad we could point you to
something that "broadened the horizon".

> . I enjoy his
> humor, but I know others do not,
>

I used to enjoy it, but after a while, I just found it diluting the
density of information too much. But you're right: it's a matter of
taste.

--
Thomas Borchert (EDDH)

Grumman-581[_3_]

September 28th 06, 08:03 PM

"Roger (K8RI)" > wrote in message
...
> In an emergency I could use *all* of that fuel considered unusable but
> I'd not want to have to do a go around or any steep climbs and all
> turns would need to be right on the ball for coordination. IOW
> depending on those 11 gallons would not be smart at all.

So, you could basically use the 11 gallons to get you over the airport and
plan for a deadstick landing from that point... Interesting...

Roger (K8RI)

September 29th 06, 02:15 AM

On Thu, 28 Sep 2006 19:03:14 GMT, "Grumman-581"
> wrote:

>"Roger (K8RI)" > wrote in message
...
>> In an emergency I could use *all* of that fuel considered unusable but
>> I'd not want to have to do a go around or any steep climbs and all
>> turns would need to be right on the ball for coordination. IOW
>> depending on those 11 gallons would not be smart at all.
>
>So, you could basically use the 11 gallons to get you over the airport and
>plan for a deadstick landing from that point... Interesting...

I was thinking on having the engine quit on roll out, but one is just
a foolish as the other. <:-)) The amount of adrenalin might be
different though.

>
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Grumman-581[_4_]

September 29th 06, 02:22 AM

Roger (K8RI) wrote:
> I was thinking on having the engine quit on roll out, but one is just
> a foolish as the other. <:-)) The amount of adrenalin might be
> different though.

One could argue that having the engine quit when you're 2000 ft over
the center of the runway is preferable to having it quit unexpectedly
while you're trying to fly a normal pattern and trying to get that last
drop of fuel out of the tank by making your turns "just right"... At
least you *know* what is about to happen and you don't have to consider
much in the way of alternatives...

Roger[_4_]

September 29th 06, 04:27 AM

On 28 Sep 2006 18:22:47 -0700, "Grumman-581" >
wrote:

>Roger (K8RI) wrote:
>> I was thinking on having the engine quit on roll out, but one is just
>> a foolish as the other. <:-)) The amount of adrenalin might be
>> different though.
>
>One could argue that having the engine quit when you're 2000 ft over
>the center of the runway is preferable to having it quit unexpectedly

You could but I was climbing out at something like a 100 MPH and 30 to
50 feet above a 3800 foot runway.

>while you're trying to fly a normal pattern and trying to get that last
>drop of fuel out of the tank by making your turns "just right"... At
>least you *know* what is about to happen and you don't have to consider
>much in the way of alternatives...

If I ever do make such a mistake I can guarantee I'll not be flying a
normal pattern<:-)) However being paranoid about fuel it's highly
unlikely I'll face such a situation unless a tank or fuel line breaks.

Oh! I forgot about the day it quit on a missed approach at roughly 400
feet. Before the instructor could holler, "Left tank Rog! LEFT TANK!"
I had already switched.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Mxsmanic

September 29th 06, 05:21 AM

Roger (K8RI) writes:

> I was thinking on having the engine quit on roll out, but one is just
> a foolish as the other. <:-)) The amount of adrenalin might be
> different though.

See

http://www.alexisparkinn.com/photogallery/Videos/2006-3-11_bob_hoover.avi

He apparently prefers to fly without engines.

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

Grumman-581[_4_]

September 29th 06, 05:25 AM

Roger wrote:
> You could but I was climbing out at something like a 100 MPH and 30 to
> 50 feet above a 3800 foot runway.

Well, one could argue that your options there aren't that many...
Basically look in front of you and try to hit the softer objects if at
all possible... If you do everything right, maybe you'll get it back
down and stopped before the end of the runway... Even better, maybe
the plane will be reusable afterwards... It's not like you're going to
try to do a 180 at that altitude...

> If I ever do make such a mistake I can guarantee I'll not be flying a
> normal pattern<:-)) However being paranoid about fuel it's highly
> unlikely I'll face such a situation unless a tank or fuel line breaks.

Nothing quite as loud as that deafening silence of the engine not
running... I had that once at 14,500 ft... It was so loud that it woke
me up... Yeah, there's probably a good reason why you should have
supplemental O2 at that altitude...

> Oh! I forgot about the day it quit on a missed approach at roughly 400
> feet. Before the instructor could holler, "Left tank Rog! LEFT TANK!"
> I had already switched.

I was thinking back to see when was the last time I botched a landing
so bad that I needed to go around... On runways with sufficient length,
I suspect it was probably around 8 years ago, probably not too long
after I had bought my Grumman... Since then, there have been a few
airports that had rather short runways and it might take a couple of
tries to get to the point where I was positive that I would be able to
get it down at the very start of the runway and stopped by the end of
the runway... There was one little grass strip up in Iowa (7IA3) that
at 2100 ft sure did seem short the first time I went in there and I
probably did a few flybys trying to get lined up just right for it, but
given any runway at least 3000 ft in length, I don't think I've had any
cases where I needed to go around because I botched the landing in
probably the last 8 years... Yeah, there's been the occasional case of
having to go around because someone didn't clear the runway quick
enough (even though I would have been stopped before getting to where
they were located)... As such, I suspect that starting at 2000 ft above
the runway and in the middle of the airport, I should not have a
problem getting a good landing out of it... Most of my landings consist
of turning final and still being at 1000 ft, pulling power back to idle
at that point, and not adding power until I need to taxi after
landing... Getting from 2000 ft to 1000 ft and being on final at that
point should be doable... Hmmm... Sounds like a good excuse to go
practice some... Not that I ever expect to run out of fuel at 2000 ft
above the center of an airport... <grin>

Roger (K8RI)

September 29th 06, 09:17 PM

On Fri, 29 Sep 2006 06:21:34 +0200, Mxsmanic >
wrote:

>Roger (K8RI) writes:
>
>> I was thinking on having the engine quit on roll out, but one is just
>> a foolish as the other. <:-)) The amount of adrenalin might be
>> different though.
>
>See
>
>http://www.alexisparkinn.com/photogallery/Videos/2006-3-11_bob_hoover.avi

I've seen Bob do his engine out maneuvers many times. He knew that
airplane, its limits and its requirements. He probably remembers more
about that airplane (which is now at the Smithsonian as I understand)
than I've ever known about the Deb. He used to read these news groups
but I've not seen him for a while.

Bob is a normal down-to-earth sort with a great sense of humor and an
ability to help with a wealth of ideas.

>
>He apparently prefers to fly without engines.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Margy Natalie

September 30th 06, 01:59 AM

Roger (K8RI) wrote:
> On Fri, 29 Sep 2006 06:21:34 +0200, Mxsmanic >
> wrote:
>
>
>>Roger (K8RI) writes:
>>
>>
>>>I was thinking on having the engine quit on roll out, but one is just
>>>a foolish as the other. <:-)) The amount of adrenalin might be
>>>different though.
>>
>>See
>>
>>http://www.alexisparkinn.com/photogallery/Videos/2006-3-11_bob_hoover.avi
>
>
> I've seen Bob do his engine out maneuvers many times. He knew that
> airplane, its limits and its requirements. He probably remembers more
> about that airplane (which is now at the Smithsonian as I understand)S
The Shrike it at the Steven F. Udvar-Hazy center of the National Air and
Space Museum, Smithsonian Institution. Very few visitors look at that
aircraft and think aerobatics. Bob Hoover is probably the best example
of energy conservation I've ever seen. Flying that aircraft, the way he
did was exceptional.

> than I've ever known about the Deb. He used to read these news groups
> but I've not seen him for a while.
>
> Bob is a normal down-to-earth sort with a great sense of humor and an
> ability to help with a wealth of ideas.
His wife Colleen makes him seem boring and mundane. She is quite fun.
>
>
>>He apparently prefers to fly without engines.
>
> Roger Halstead (K8RI & ARRL life member)
> (N833R, S# CD-2 Worlds oldest Debonair)
> www.rogerhalstead.com

Roger (K8RI)

September 30th 06, 05:30 AM

On 28 Sep 2006 21:25:12 -0700, "Grumman-581" >
wrote:

>Roger wrote:
>> You could but I was climbing out at something like a 100 MPH and 30 to
>> 50 feet above a 3800 foot runway.
>
>Well, one could argue that your options there aren't that many...

That they could.

>Basically look in front of you and try to hit the softer objects if at
>all possible... If you do everything right, maybe you'll get it back
>down and stopped before the end of the runway... Even better, maybe
>the plane will be reusable afterwards... It's not like you're going to
>try to do a 180 at that altitude...

That altitude is probably low enough to discourage even the most
panicked from trying to turn back. <:-)) OTOH I'd not hesitate to take
a slight and shallow turn to keep it on the airport if I could do it
with out digging in a wing. Better to wipe out the gear or underside
and remain in control than turn into a cartwheeling ball of fire.

>
>> If I ever do make such a mistake I can guarantee I'll not be flying a
>> normal pattern<:-)) However being paranoid about fuel it's highly
>> unlikely I'll face such a situation unless a tank or fuel line breaks.
>
>Nothing quite as loud as that deafening silence of the engine not
>running... I had that once at 14,500 ft... It was so loud that it woke

I'm not so sure. I thought I had some one in the back seat beating on
a drum until I realized it was my pulse in my ears. <:-))

>me up... Yeah, there's probably a good reason why you should have
>supplemental O2 at that altitude...
>
>> Oh! I forgot about the day it quit on a missed approach at roughly 400
>> feet. Before the instructor could holler, "Left tank Rog! LEFT TANK!"
>> I had already switched.
>
>I was thinking back to see when was the last time I botched a landing
>so bad that I needed to go around... On runways with sufficient length,

This wasn't a go around, but rather the missed after doing the ILS
down to DH which was 200 AGL at the MM. This was after more than 3
hours of shooting approaches at three different airports. NDB,
Localizer only, VOR, ILS, and partial panel. Seems like we did a PAR
some where in there as well.

>I suspect it was probably around 8 years ago, probably not too long
>after I had bought my Grumman... Since then, there have been a few
>airports that had rather short runways and it might take a couple of
>tries to get to the point where I was positive that I would be able to
>get it down at the very start of the runway and stopped by the end of
>the runway... There was one little grass strip up in Iowa (7IA3) that
>at 2100 ft sure did seem short the first time I went in there and I

2100 is plenty to get into and out of with the 260 HP engine in the
Deb. It's a very good short field plane with big wings and about the
same wing loading as a Cherokee.

>probably did a few flybys trying to get lined up just right for it, but
>given any runway at least 3000 ft in length, I don't think I've had any
>cases where I needed to go around because I botched the landing in
>probably the last 8 years... Yeah, there's been the occasional case of
>having to go around because someone didn't clear the runway quick
>enough (even though I would have been stopped before getting to where
>they were located)... As such, I suspect that starting at 2000 ft above
>the runway and in the middle of the airport, I should not have a
>problem getting a good landing out of it... Most of my landings consist
>of turning final and still being at 1000 ft, pulling power back to idle

In the Deb you typically don't do power off landings as they are
faster than power on, shallower, and use a *lot* more runway. Close
to twice as much without using short field techniques and even then
they are longer than the power on short field.

>at that point, and not adding power until I need to taxi after
>landing... Getting from 2000 ft to 1000 ft and being on final at that
>point should be doable... Hmmm... Sounds like a good excuse to go
>practice some... Not that I ever expect to run out of fuel at 2000 ft
>above the center of an airport... <grin>

I really didn't run out of fuel in either case. In the one I only had
to switch tanks. In the other case the diaphragm in the spider on top
of the engine had blown and all the fuel was spraying all over that
hot engine. You can put a lot of fuel through a 1/4" diameter hole at
close to 16 PSI in a hurry.

I'd really like to thank who ever was my instructor at the ASF/ABS Bo
specific pilot proficiency training for beating that failed engine
process into my head, over and over and over and over...etc. When the
engine quit I didn't even have to stop to think or consciously
recognize what had happened or what to do. It was like being on
autopilot. Before I could have even stated to some one else what had
happened I had shut off the fuel, recognized I could not make the
highway, "picked a spot", hit full flaps and set up for a short field
power off landing. With 3800 feet of runway, I had rotated, climbed to
about 50 feet while accelerating to 100 MPH, had an engine failure,
lowered the flaps, landed, had barely enough energy to make the
taxiway in front of the terminal and had about 1200 feet of runway
left. (or possibly a tad more)
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Mxsmanic

September 30th 06, 05:34 AM

Roger (K8RI) writes:

> I've seen Bob do his engine out maneuvers many times. He knew that
> airplane, its limits and its requirements. He probably remembers more
> about that airplane (which is now at the Smithsonian as I understand)
> than I've ever known about the Deb. He used to read these news groups
> but I've not seen him for a while.

What kind of aircraft did he use? I'm not good at recognizing small
aircraft. It certainly was surprising to see what he did with it; I
didn't think that such aircraft could do that.

There's another video on the same site of a small aircraft that snaps
its wings off pulling too many g's, which proves that airframes can be
overstressed. Both wings snap at the same time, which at least
implies that they were consistently engineered.

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

Wade Hasbrouck

September 30th 06, 07:40 AM

"Roger (K8RI)" > wrote in message
...
> On Fri, 29 Sep 2006 06:21:34 +0200, Mxsmanic >
> wrote:
>
>>Roger (K8RI) writes:
>>
>>> I was thinking on having the engine quit on roll out, but one is just
>>> a foolish as the other. <:-)) The amount of adrenalin might be
>>> different though.
>>
>>See
>>
>>http://www.alexisparkinn.com/photogallery/Videos/2006-3-11_bob_hoover.avi
>
> I've seen Bob do his engine out maneuvers many times. He knew that
> airplane, its limits and its requirements. He probably remembers more
> about that airplane (which is now at the Smithsonian as I understand)
> than I've ever known about the Deb. He used to read these news groups
> but I've not seen him for a while.
>
> Bob is a normal down-to-earth sort with a great sense of humor and an
> ability to help with a wealth of ideas.
>
>>
>>He apparently prefers to fly without engines.
> Roger Halstead (K8RI & ARRL life member)
> (N833R, S# CD-2 Worlds oldest Debonair)
> www.rogerhalstead.com

I never got to see Bob Hoover perform in person, but have seen video, and he
is amazing, esecially the manuever where they show him pouring water into a
glass during a loop... Really cool.

If you have get a chance to see Kent Pietsch perform, do it. He is from
Minot, ND, and does an aerbatic engine out routine from about 6000' in an
Interstate Kadet, and all during this there is person standing on the
taxiway, and when he lands he puts the spinner of the plane right in the
person's hand. Good demonstration of "Energy Management". :-)

He also has a little comedy routine that he does that involves the aileron
falling off in the beginning, and flies in a way that you go "Wow... To fly
that 'badly' you must really have to work at it... :-)" I saw him perform
at the Abbotsford Airshow this year in Abbotsford, B.C. The link below is
to a video he has on his site for the comedy routine from a few years ago at
the Chilliwack Airshow in Chilliwack, B.C. (there is no video of the engine
out routine)
http://www.pietschaircraft.com/gallery/comedy_movie.php

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

Ron Natalie

September 30th 06, 10:52 AM

Mxsmanic wrote:
\
>
> What kind of aircraft did he use? I'm not good at recognizing small
> aircraft. It certainly was surprising to see what he did with it; I
> didn't think that such aircraft could do that.

That's a Shrike. As mentioned earlier, it currently resides in the
Udvar-Hazy center. Unlike most aircraft that arrived there, Bob
actually taxiied it into the building.
>
> There's another video on the same site of a small aircraft that snaps
> its wings off pulling too many g's, which proves that airframes can be
> overstressed. Both wings snap at the same time, which at least
> implies that they were consistently engineered.
>

That was a Partenavia. Also a high wing twin. Not just overstressed
but repeatedly overstressed. Airshow aircraft need special continual
attention.

Grumman-581[_3_]

October 1st 06, 09:33 AM

"Roger (K8RI)" > wrote in message
...
> 2100 is plenty to get into and out of with the 260 HP engine in the
> Deb. It's a very good short field plane with big wings and about the
> same wing loading as a Cherokee.

I tend to fly 85 kts on short final... Quite a bit faster if I'm going into
HOU with a 737 basically on my tail... I figure that if I get down first,
*he's* the one who has to worry about *my* wingtip vortices, not the other
way around... <grin>

I can get into a 2100 ft field, but it took me a could of tries to get lined
up so that I was going to touch down at the very start of the runway instead
of just flaring and floating for too long... Basically, I guess I had to get
comfortable with the sight picture that I was getting... I've actually
gotten into a shorter runway before, but it was paved and as such, my brakes
actually made a difference...

> In the Deb you typically don't do power off landings as they are
> faster than power on, shallower, and use a *lot* more runway. Close
> to twice as much without using short field techniques and even then
> they are longer than the power on short field.

Hmmm... Sounds like you might end up short of the runway if you lose your
engine while on approach... It's one thing to crash out in the middle of
nowhere, it seems like it would be rather embarassing when the report said
you *nearly* made it to the runway...

Margy Natalie

October 3rd 06, 12:37 AM

Mxsmanic wrote:
> Roger (K8RI) writes:
>
>
>>I've seen Bob do his engine out maneuvers many times. He knew that
>>airplane, its limits and its requirements. He probably remembers more
>>about that airplane (which is now at the Smithsonian as I understand)
>>than I've ever known about the Deb. He used to read these news groups
>>but I've not seen him for a while.
>
>
> What kind of aircraft did he use? I'm not good at recognizing small
> aircraft. It certainly was surprising to see what he did with it; I
> didn't think that such aircraft could do that.

Shrike
>
> There's another video on the same site of a small aircraft that snaps
> its wings off pulling too many g's, which proves that airframes can be
> overstressed. Both wings snap at the same time, which at least
> implies that they were consistently engineered.
>

Roger (K8RI)

October 3rd 06, 07:45 AM

On Sun, 01 Oct 2006 08:33:07 GMT, "Grumman-581"
> wrote:

>"Roger (K8RI)" > wrote in message
...
>> 2100 is plenty to get into and out of with the 260 HP engine in the
>> Deb. It's a very good short field plane with big wings and about the
>> same wing loading as a Cherokee.
>
>I tend to fly 85 kts on short final... Quite a bit faster if I'm going into
>HOU with a 737 basically on my tail... I figure that if I get down first,
>*he's* the one who has to worry about *my* wingtip vortices, not the other
>way around... <grin>
>
>I can get into a 2100 ft field, but it took me a could of tries to get lined
>up so that I was going to touch down at the very start of the runway instead
>of just flaring and floating for too long... Basically, I guess I had to get
>comfortable with the sight picture that I was getting... I've actually
>gotten into a shorter runway before, but it was paved and as such, my brakes
>actually made a difference...
>
>> In the Deb you typically don't do power off landings as they are
>> faster than power on, shallower, and use a *lot* more runway. Close
>> to twice as much without using short field techniques and even then
>> they are longer than the power on short field.
>
>Hmmm... Sounds like you might end up short of the runway if you lose your
>engine while on approach... It's one thing to crash out in the middle of
>nowhere, it seems like it would be rather embarassing when the report said
>you *nearly* made it to the runway...

Just one of those facts of life that keep some people from flying high
performance or twins.

However you can come in power off at the proper speed which is
*steep*. Use a bit of power into the flare. Otherwise drop the nose a
tad at the right time to gain just enough speed/energy to flare. The
steep round out into the flare will let you bleed off most of the
extra speed. The only down side is it takes plenty of practice and
there is less margin for error.

It doesn't take much technique to land the Deb shorter than book
figures. OTOH I'd not want to need to beat them on take off even with
the extra HP.
>
>
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger (K8RI)

October 3rd 06, 07:56 AM

On Sun, 01 Oct 2006 08:33:07 GMT, "Grumman-581"
> wrote:

>"Roger (K8RI)" > wrote in message
...
>> 2100 is plenty to get into and out of with the 260 HP engine in the
>> Deb. It's a very good short field plane with big wings and about the
>> same wing loading as a Cherokee.
>
>I tend to fly 85 kts on short final... Quite a bit faster if I'm going into

I come down short final at 80 *MPH* minus one MPH for each 100# under
gross.

>HOU with a 737 basically on my tail... I figure that if I get down first,
>*he's* the one who has to worry about *my* wingtip vortices, not the other
>way around... <grin>

I had ATC request I keep the speed as long as practicable one day as
I had a DC-9 coming up behind me. Actually the pilot was one of our
EAA chapter members. At any rate we'd been out doing approaches in a
Mooney with me as safety pilot and then the Mooney pilot was serving
as safety pilot for me.I normally intercept the localizer at 120, but
I kept it up to 180 then came back on the power as we flew down the
ILS with the gear still up. When the DME said I was a mile from the
MM I took the foggles off, did a couple of S-turns to reach gear down
speed, added a tad of flaps, dumped the gear when we hit 140, two
more S-turns, straightened out, full flaps and set it down on the
touchdown zone at a normal speed. (I'm not that well practiced at
present) The Mooney pilot laughed and said had we done that in his
plane we'd have stopped some where in that big bean field off the
other end of the 8,000 foot runway.

>
>I can get into a 2100 ft field, but it took me a could of tries to get lined
>up so that I was going to touch down at the very start of the runway instead
>of just flaring and floating for too long... Basically, I guess I had to get
>comfortable with the sight picture that I was getting... I've actually
>gotten into a shorter runway before, but it was paved and as such, my brakes
>actually made a difference...

It takes practice and it took me a while to get to know the Deb to the
point where I'd go into short fields, or as above, keep the speed up.

>
>> In the Deb you typically don't do power off landings as they are
>> faster than power on, shallower, and use a *lot* more runway. Close
>> to twice as much without using short field techniques and even then
>> they are longer than the power on short field.
>
>Hmmm... Sounds like you might end up short of the runway if you lose your
>engine while on approach... It's one thing to crash out in the middle of
>nowhere, it seems like it would be rather embarassing when the report said
>you *nearly* made it to the runway...

I've only had one real engine failure and that was on departure. I'd
never realized my pulse was that loud.

>
>
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com