Constant speed props

I don't wish to sound like a smartass here, but what's your problem with
getting a full checkout in this airplane from a competent pilot current
in the aircraft?
It sounds like you might benefit from a bit of complex training here!!!
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt
"Greg Copeland" wrote in message
news
On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:

In article , GE
wrote:

I'm taking delivery today of my first aircraft and it had a
constant speed
prop. I have only flown fixed props thus far. I want to have as
much
understanding of the c-s prop as possible before I get with my
instructor. I
understand the basic difference in what the controls do, but I
don't really
have a good understanding of the hows and whys of flying with them.
Any
general information, explanations, and tips would be greatly
appreciated.

Go to www.avweb.com
on the left side of the screen, select COLUMNS
scroll down to find THE PELICAN"S PERCH
there are articles on fuel injection, manifold pressure, constant
speed
props, leaning, etc
Everything you ever want to know about operating a high performance
aircraft engine is in those articles.


Great link!

I started reading this
article, http://www.avweb.com/news/columns/186619-1.html, and have a
question. In the Runup section, when he starts to test for proper mag
operation, somethings seems odd there. Can someone help explain that?
He
says, "Are the mags working? The leaner the mixture, the more mag drop
you'll see on one mag, and that's normal." He then goes on to say,
"The
EGTs should rise on the first single-mag operation, stay there for the
second, then drop again on the return to BOTH. That rise is
proof-positive
the entire ignition system is working, and working well, and the
leaner
the mixture, the more diagnostic it is."

Can someone help explain the supporting logic there? If both mags are
working properly and you switch to a single mag, why would the EGT go
up?
After all, in theory, you're producing less spark and thusly, a
slightly
less effecient ignition of the fuel/air. I would of thought that EGT
would stay the same or go down *just slightly* when running off of one
mag. Likewise, if one mag is not working, I would fully expect to see
a
big EGT drop for the given problematic mag, which he does agree with.
But, he further asserts that, "If any of them fail to rise or even
drop
during single-mag operation, there is a problem with that plug, the
wire,
or the mag."

So, why would running on one mag, versus two, always cause higher
EGTs?
And why would no rise in EGT indicate a bad mag, wire or plug?

Anyone?


P.S. I cross posted because this seems like good student pilot
material
too.

The initial poster asking these questions sounds like he might benefit
from a complex checkout, or at least a thorough checkout in this
airplane given by a competent pilot current in the aircraft!
:-)
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt
"Greg Copeland" wrote in message
news
On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:

In article , GE
wrote:

I'm taking delivery today of my first aircraft and it had a
constant speed
prop. I have only flown fixed props thus far. I want to have as
much
understanding of the c-s prop as possible before I get with my
instructor. I
understand the basic difference in what the controls do, but I
don't really
have a good understanding of the hows and whys of flying with them.
Any
general information, explanations, and tips would be greatly
appreciated.

Go to www.avweb.com
on the left side of the screen, select COLUMNS
scroll down to find THE PELICAN"S PERCH
there are articles on fuel injection, manifold pressure, constant
speed
props, leaning, etc
Everything you ever want to know about operating a high performance
aircraft engine is in those articles.


Great link!

I started reading this
article, http://www.avweb.com/news/columns/186619-1.html, and have a
question. In the Runup section, when he starts to test for proper mag
operation, somethings seems odd there. Can someone help explain that?
He
says, "Are the mags working? The leaner the mixture, the more mag drop
you'll see on one mag, and that's normal." He then goes on to say,
"The
EGTs should rise on the first single-mag operation, stay there for the
second, then drop again on the return to BOTH. That rise is
proof-positive
the entire ignition system is working, and working well, and the
leaner
the mixture, the more diagnostic it is."

Can someone help explain the supporting logic there? If both mags are
working properly and you switch to a single mag, why would the EGT go
up?
After all, in theory, you're producing less spark and thusly, a
slightly
less effecient ignition of the fuel/air. I would of thought that EGT
would stay the same or go down *just slightly* when running off of one
mag. Likewise, if one mag is not working, I would fully expect to see
a
big EGT drop for the given problematic mag, which he does agree with.
But, he further asserts that, "If any of them fail to rise or even
drop
during single-mag operation, there is a problem with that plug, the
wire,
or the mag."

So, why would running on one mag, versus two, always cause higher
EGTs?
And why would no rise in EGT indicate a bad mag, wire or plug?

Anyone?


P.S. I cross posted because this seems like good student pilot
material
too.

"C J Campbell" wrote in message
...
I think Deakin is worth reading, but some of what he says should be taken
with a grain of salt. His columns are mostly based on experiments with his
own highly modified Bonanza, a few high performance radial engines, and
some
theory. In fact, a careful reading of his columns will show no test data
for
the most common engine and propeller combinations in use today.

You've not read hiscolumns about the test beds they've run at GAMI?


The reasons
for this are fairly simple -- few airplanes have the instrumentation that
Deakin needs to test his theories. This is why Deakin's theories for
running
lean of peak remain a minority view. Granted, it is a very noisy minority,
but remember that it is also a small minority. I think they have a point.
They may even be right. But they don't have nearly the evidence that they
think they have.

See above.

Deakin's remarks are mostly pertinent to running TCM engines, which are
much
different than engines from other manufacturers.

I bellieve they run Lycoming on the test bed as well, everything from
pipsqueaks to the big 540's.

Not to put too fine a point
on it, some TCM engines are the only ones I know of that so consistently
develop cracks that the most part of an annual inspection basically
consists
of measuring and cataloging the spread of these cracks. The engine used in
the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for
example.

Barring solid data to the contrary (and Deakin, remember, does not give
you
solid data -- he only appears to do that), your airplane should be
operated
in accordance with the manufacturer's recommendations. This will ensure
that
you maintain your insurance coverage, if nothing else.

I think GAMI generated enough data on their stand to run a computer dry.

http://www.engineteststand.com/

I also highly recommend John C Eckalbar's books

FLYING THE BEECH BONANZA

and

FLYING HIGH PERFORMANCE SINGLES AND TWINS

These books will describe the relationship between aircraft weight and
the various V-speeds you should know when you fly.

On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:

I don't wish to sound like a smartass here, but what's your problem with
getting a full checkout in this airplane from a competent pilot current
in the aircraft?
It sounds like you might benefit from a bit of complex training here!!!
Dudley Henriques


I wondered the same thing, but you're replying to the wrong person. I'm a
student and GE posted the original question.

Cheers!

I caught that right after I posted it :-) I had cleaned out OE last
night back to four days old and missed the pickup. Thought I had
deleted this but obviously it didn't work!
Anyway.....it looks to me like the IP needs a complete checkout in this
airplane before flying it. His questions just seem way out of line for
someone taking delivery of an airplane they are rated and competent to
fly!
Sorry about the mispost :-)
DH
"Greg Copeland" wrote in message
news
On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:

I don't wish to sound like a smartass here, but what's your problem
with
getting a full checkout in this airplane from a competent pilot
current
in the aircraft?
It sounds like you might benefit from a bit of complex training
here!!!
Dudley Henriques


I wondered the same thing, but you're replying to the wrong person.
I'm a
student and GE posted the original question.

Cheers!

On Thu, 24 Jun 2004 09:14:59 -0700, Tom Sixkiller wrote:


"C J Campbell" wrote in message
...
I think Deakin is worth reading, but some of what he says should be taken
with a grain of salt. His columns are mostly based on experiments with his
own highly modified Bonanza, a few high performance radial engines, and
some
theory. In fact, a careful reading of his columns will show no test data
for
the most common engine and propeller combinations in use today.

You've not read hiscolumns about the test beds they've run at GAMI?


The reasons
for this are fairly simple -- few airplanes have the instrumentation that
Deakin needs to test his theories. This is why Deakin's theories for
running
lean of peak remain a minority view. Granted, it is a very noisy minority,
but remember that it is also a small minority. I think they have a point.
They may even be right. But they don't have nearly the evidence that they
think they have.

See above.

Deakin's remarks are mostly pertinent to running TCM engines, which are
much
different than engines from other manufacturers.

I bellieve they run Lycoming on the test bed as well, everything from
pipsqueaks to the big 540's.

Not to put too fine a point
on it, some TCM engines are the only ones I know of that so consistently
develop cracks that the most part of an annual inspection basically
consists
of measuring and cataloging the spread of these cracks. The engine used in
the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for
example.

Barring solid data to the contrary (and Deakin, remember, does not give
you
solid data -- he only appears to do that), your airplane should be
operated
in accordance with the manufacturer's recommendations. This will ensure
that
you maintain your insurance coverage, if nothing else.

I think GAMI generated enough data on their stand to run a computer dry.

http://www.engineteststand.com/

Is the data offered in the articles you refer to or is it available on
the web site? It does not appear to be jumping out at me. I see a couple
of pictures of some graphs, a webring link, and email address, and a link
to gami.com. What am I missing?

Thanks,

Greg

On Thu, 24 Jun 2004 08:55:30 -0700, "C J Campbell"
wrote:

I think Deakin is worth reading, but some of what he says should be taken
with a grain of salt. His columns are mostly based on experiments with his
own highly modified Bonanza, a few high performance radial engines, and some
theory. In fact, a careful reading of his columns will show no test data for
the most common engine and propeller combinations in use today. The reasons
for this are fairly simple -- few airplanes have the instrumentation that
Deakin needs to test his theories. This is why Deakin's theories for running
lean of peak remain a minority view. Granted, it is a very noisy minority,
but remember that it is also a small minority. I think they have a point.
They may even be right. But they don't have nearly the evidence that they
think they have.

Deakin's Bonanza is highly modified? I thought it had an ordinary
Continental TIO-550. Or is that engine considered highly modified?

Far as I know, from what I've read, the only extra instrument he has
on his instrument panel is the JPI EGT analyzer. He has said
repeatedly that in order to take advantage of running the engine lean
of peak, you really have to have a multi cylinder EGT guage, otherwise
you do not know if you are truly running all the cylinders lean of
peak. One or two may still be on the rich side or at peak which would
cause them to run a lot hotter than the lean ones.

Deakin's remarks are mostly pertinent to running TCM engines, which are much
different than engines from other manufacturers. Not to put too fine a point
on it, some TCM engines are the only ones I know of that so consistently
develop cracks that the most part of an annual inspection basically consists
of measuring and cataloging the spread of these cracks. The engine used in
the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for example.

Barring solid data to the contrary (and Deakin, remember, does not give you
solid data -- he only appears to do that), your airplane should be operated
in accordance with the manufacturer's recommendations. This will ensure that
you maintain your insurance coverage, if nothing else.

I guess I'll have to ask why you think Deakin does not give solid
evidence for his recommendations. The GAMI folks (who's testing he
repeatedly cites) have been testing different types of engines for
years, and developed their precision injectors and proved them with
more testing before marketing them.

In addition, running engines lean of peak isn't new. When radial
engines were what powered most commercial aircraft, cruising them lean
of peak is what just about every pilot was trained to do. My father,
who flew PB4Y-1's and -2's and P2V Neptunes used to tell me about
flying them and how he set up for cruise and he mentioned the leaning
process. Ernest Gann talked about it. There were even percentage of
horsepower instruments in the big engined airliners that pilots were
required to adjust the engines to using the lean of peak setting. It
was the only way to get maximum range out of the airplane, at
reasonable speed.

Charles A. Lindbergh rather famously demonstrated to pilots in the
South Pacific during WWII how to greatly extend their range using lean
of peak operation. The technique worked for the F4U Corsair, the P-47
Thunderbolt, and most famously, the P-38 Lightning. The Lightning's
range was extended to such a degree that it permitted the large twin
engined fighter to accompany a bombing raid on a northern New Guinea
Japanese airbase, which had previously been out of range for fighters.
The Japanese were totally unprepared for the attack as they had
believed no bombing force would dare attack without fighter escort,
and they believed no American fighter had the range to make the trip
from Port Moresby. The attack is sometimes cited as perhaps the single
most effective raid of it's type in the Pacific War. How did
Lindbergh learn about lean of peak operation? I have no idea when he
first learned it or who taught him, but he knew about it when he made
his sort of well known solo trip across the Atlantic Ocean. He leaned
the engine visually, by leaning out the window and watching the
exhaust flame change color as he leaned the engine.

Deakin, as he stated several times in several different articles,
isn't introducing something new. He's re-intruducing a technique that
is old and well proven. It just did not work well with horizontally
opposed aircraft engines until now. It worked very well for radials
because the big ones all had impellers and equal length intake
manifold runners. The impellers distributed exactly the same fuel/air
mixture to each and every cylinder, every time it was ready to fire.
Horizontally opposed engines don't have the benefit of equal fuel/air
mixture being distributed to each cylinder. The GAMI people fix this
by taking your EGT readings which you give them when you install a
multi cylinder EGT guage and record the temperatures for each
cylinder. Then they send you a set of injectors calibrated for each
specific cylinder. If you install them properly (in the correct
cylinders, which is very important), the rich cylinders will be leaned
and the lean cylinders richened. The cylinder to cylinder
distribution now becomes equal enough that leaning should not produce
any rough engine operation. Some people had to return an injector to
be recalibrated, sometimes several times, but eventually the EGT's
reach relative uniformity.

If you can run the engine lean of peak without engine roughness, which
creates less heat in the engine, why would you not want to do that?
Less heat, less fuel burned, nearly the same speed at cruise (a little
less), what's wrong with this picture, anything? Can anyone explain
how this could possibly hurt the engine? It can't burn valves because
they are running cooler than they would if the mixture were set to
rich of peak operation. You can't cause detonation because that's a
result of heat and high power settings. The lean of peak setting is
normally used at or above 7,000 to 8,000 feet where no normally
aspirated engine is producing more than 60 or 65% power. With that
percentage of power, it's impossible to cause detonation. Even
Lycoming agrees with this.

Unless you really need to get somewhere at maximum possible speed, in
which case you would run the engine for best power which is a setting
on the rich side of peak, I don't understand why everyone would not
want to set for lean of peak cruise, when possible, if they have the
right instrumentation and the engine tolerates it.

It's possible that the POH's specify rich of peak operation because
that produces the highest cruise speeds, which is often what sells the
airplane.

Corky Scott

On Thu, 24 Jun 2004 17:47:41 GMT, "Dudley Henriques"
wrote:

I caught that right after I posted it :-) I had cleaned out OE last
night back to four days old and missed the pickup. Thought I had
deleted this but obviously it didn't work!
Anyway.....it looks to me like the IP needs a complete checkout in this
airplane before flying it. His questions just seem way out of line for
someone taking delivery of an airplane they are rated and competent to
fly!
Sorry about the mispost :-)
DH
"Greg Copeland" wrote in message
news
On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:

I don't wish to sound like a smartass here, but what's your problem
with
getting a full checkout in this airplane from a competent pilot
current
in the aircraft?
It sounds like you might benefit from a bit of complex training
here!!!
Dudley Henriques


I wondered the same thing, but you're replying to the wrong person.
I'm a
student and GE posted the original question.

Cheers!



I applaud the original poster. He said, " I have only flown fixed
props thus far. I want to have as much
understanding of the c-s prop as possible before I get with my
instructor." He's trying to learn a little something in advance so he
doesn't start completely cold with the instructor. He is seeking
complex training and proactively preparing in advance for that
training.
Rich Russell

Dudley Henriques wrote:

I caught that right after I posted it :-) I had cleaned out OE last
night back to four days old and missed the pickup. Thought I had
deleted this but obviously it didn't work!
Anyway.....it looks to me like the IP needs a complete checkout in this
airplane before flying it. His questions just seem way out of line for
someone taking delivery of an airplane they are rated and competent to
fly!
Sorry about the mispost :-)


FWIW, I just (today!) completed complex and high performance checkouts.
Before I started the actual work, though, I read a fair bit on both the
specific aircraft and constant-speed prop use in general.

[I even posted some questions here, I believe.]

Reading ahead is never a bad idea, in my experience (granted: I don't read
many mysteries {8^).

- Andrew