Extended full-power in small pistons

There is a lot of "may", or "can" in their article, but no data. On the
other hand, Cirrus as well as the folks at TAT actually present data,
something that Lycoming and Continental have yet to produce.

I suspect that both companies are not interested in doing any testing or
changing their many year old operating instructions in order to limit their
liability exposure.

In rec.aviation.student Mxsmanic wrote:
Michael Ash writes:

This is the kind of amusing idealism that is common from someone not very
well versed in the real world.

I don't think there's anything idealistic about it. My guess is that
certification of engines is so extraordinarily expensive, and private plane
owners are so (relatively) poor, that nobody could afford to pay for a truly
modern piston engine. So the same designs are used for decades.

What a total non sequitur. The idealism was referring to your statement
that it would be great if pilots could just concentrate on the flying and
ignore the engine. Well it's true, it would be great, but there's this
little thing called reality which gets in the way.

It's like saying "wouldn't it be great if everybody could just get
together in harmony and we wouldn't fight war no more". Well yes, it
would, but that sort of thinking is still hopelessly idealistic,
especially when you run with it instead of just having it as a passing
fancy.

The situation is different with airlines, because they have more money and can
save more money. The economics favor advances in engine design and control,
and certification is much less of an expense.

At least that's my guess. But it does keep private pilots back in the 1940s.

Airliners may have better engine management systems but it's still there.
And don't paint all private pilots with the same brush. There are great
differences from one type of plane to another.

I used to feel the same way, but reality simply is not cooperative in this
respect. Technology can compensate to some degree. You no longer need to
know very much about cars at all to own one (for which I am eternally
grateful). But you still need to know some things. The car can't protect
you against everything. You still have to think about when to get your oil
changed (even if the computer reminds you), you still have to know that
shifting into reverse while on the highway is not a good move, etc.

Yes, but you don't have to adjust mixture and timing as you drive. You don't
have to worry about the exhaust temperature. You have a cooling system that
doesn't vary dramatically in efficiency with your speed. And so on.

Yep, but my point is that you still have to think about it to *some*
extent. Try starting the car in -20 degree weather, then immediately
flooring it while in park and holding the pedal to the floor until the gas
runs out. This is going to do bad things. Try driving around in 1st gear
all the time, ditto, even though it will force an upshift at redline. Try
hooking up a big fat trailer to a small car and then driving up and down
big mountains at 70MPH, your transmission will be lucky to last the week.

If you think engine management is distracting, you should see what *I*
have to go through to stay aloft. All sorts of thinking going on there.
And yet I and every other glider pilot manages to fly the plane too.

But glider pilots like going through the extra stuff, otherwise they wouldn't
be glider pilots. And you don't have to worry about an engine.

And you think that no power pilots like engine management? From what I've
seen, for a significant proportion of these guys, getting maximum
performance out of the engine, minimizing fuel burn, holding CHT to the
exact right value, and tweaking that last few miles of range out of the
engine is an enormous thrill. I don't share in that enthusiasm myself but
it's definitely there in some guys.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

On 3-Jan-2009, "Viperdoc" wrote:

I suspect that both companies are not interested in doing any testing or
changing their many year old operating instructions in order to limit
their
liability exposure.

You may be exactly right. Somewhat irrelevant for me, since my 1978 Cessna
172N doesn't have an EGT gauge or cylinder head temp gauges. My POH says to
lean until the tach drops 25 to 50 RPM, which I've read is supposedly
somewhere slightly lean of peak. My partners say they lean until the tach
drops off, then twist the mixture knob back rich a couple of turns. I do the
25 RPM drop-off method, but I've always been worried I might be causing
damage to the engine, based on what I've read in some of the on-line
articles people on this group recommended. Or maybe my partners are damaging
the engine by doing it their way, if not just wasting some gas. I wish
there was a way to be absolutely sure.
Scott Wilson

In rec.aviation.piloting Mxsmanic wrote:

I'm amazed at all the complications of piston engines on small aircraft. Big
jets used to have a flight engineer with a whole panel of controls and
instruments, but they managed to eliminate that with various forms of
automatic and engine design changes. And yet the same has not happened on
small aircraft: you practically have to be a mechanic to be a pilot, at least
in small piston aircraft. It seems like a hazardous distraction--a pilot
should be able to dedicate himself to flying, not to tweaking an engine.

That's because you don't know what you are talking about.

It was the big radial piston engines that had the "whole panel of controls
and instruments".

Turbines by their intrinsic design just don't have that many things you
can adjust in operation.


--
Jim Pennino

Remove .spam.sux to reply.

In rec.aviation.piloting Mxsmanic wrote:

The situation is different with airlines, because they have more money and can
save more money. The economics favor advances in engine design and control,
and certification is much less of an expense.

Apples and oranges.

Private pilots don't generally fly airplanes with huge turbofan enginges.

Yes, but you don't have to adjust mixture and timing as you drive. You don't
have to worry about the exhaust temperature. You have a cooling system that
doesn't vary dramatically in efficiency with your speed. And so on.

Apples and oranges.

Airplane engines are operated at near full power at all times, automobile
engines are seldom operated anywhere near full power.

Automobile engines typically operate at less than 4,000 feet while
airplane engines sans turbo operate to around 10,000 feet. Before the
days of modern fuel injection, people who lived in places like Denver
had different jets in the carb than people down in the flats since cars
didn't have mixture controls.


--
Jim Pennino

Remove .spam.sux to reply.

In rec.aviation.piloting wrote:

On 3-Jan-2009, "Viperdoc" wrote:

I suspect that both companies are not interested in doing any testing or
changing their many year old operating instructions in order to limit
their
liability exposure.

You may be exactly right. Somewhat irrelevant for me, since my 1978 Cessna
172N doesn't have an EGT gauge or cylinder head temp gauges. My POH says to
lean until the tach drops 25 to 50 RPM, which I've read is supposedly
somewhere slightly lean of peak. My partners say they lean until the tach
drops off, then twist the mixture knob back rich a couple of turns. I do the
25 RPM drop-off method, but I've always been worried I might be causing
damage to the engine, based on what I've read in some of the on-line
articles people on this group recommended. Or maybe my partners are damaging
the engine by doing it their way, if not just wasting some gas. I wish
there was a way to be absolutely sure.
Scott Wilson

There is; it is called an engine analyzer.


--
Jim Pennino

Remove .spam.sux to reply.

wrote in message
.. .

On 3-Jan-2009, "Viperdoc" wrote:

I suspect that both companies are not interested in doing any testing or
changing their many year old operating instructions in order to limit
their
liability exposure.

You may be exactly right. Somewhat irrelevant for me, since my 1978 Cessna
172N doesn't have an EGT gauge or cylinder head temp gauges. My POH says
to
lean until the tach drops 25 to 50 RPM, which I've read is supposedly
somewhere slightly lean of peak. My partners say they lean until the tach
drops off, then twist the mixture knob back rich a couple of turns. I do
the
25 RPM drop-off method, but I've always been worried I might be causing
damage to the engine, based on what I've read in some of the on-line
articles people on this group recommended. Or maybe my partners are
damaging
the engine by doing it their way, if not just wasting some gas. I wish
there was a way to be absolutely sure.
Scott Wilson

I don't know about the 172N, but the manual for the 152 had a very similar
recommendation for lean operation--but it was stated for 60% power (and was
obviously appropriate for less than 60% as well).

What does your POH say about the power setting?

Peter

On 3-Jan-2009, wrote:

There is; it is called an engine analyzer.


--
Jim Pennino

Ah yes, the Holy Grail of operating an engine. Not in our budget
unfortunately; our airplane is completely original, including paint,
interior and the original Cessna avionics. The best thing about our airplane
is that we have a little less than 2600 total hours on it, and she's been
hangared all her life so she's in remarkably good condition. But, we need to
upgrade the radios and transponder before we start looking at engine
analyzers. Guess I should've been more clear; I wish there were a way to be
more sure of operating the engine properly without an analyzer. Thanks for
the thought, though!
Scott Wilson

Clark wrote:
"Beauciphus" wrote in news:Qpo7l.250572$Mh5.22990
@bgtnsc04-news.ops.worldnet.att.net:

"Mxsmanic" wrote in message
...
The POH for a number of small piston aircraft warn that high power and
prop
settings should not be used for extended periods. What counts as an
extended
period, and what happens to the engine if these recommended (or mandatory)
limits are exceeded?
I guess I need to apologise for my previous remark. As it turns out, I mis
read the question.

My aircraft has large pistons, not small ones, and my remarks refer to
aircraft with large pistons, not small pistons.

braggart!




Hey... In aviation, the size of your piston counts.

Viperdoc writes:

There is no question that it would be ideal to have an aircraft engine work
like a car engine, e.g. FADEC. However, complexity also adds further
possible failure modes.

True, but nowadays most of the complexity is in the G1000, not the engines.
I'd trust a FADEC in an airliner long before I'd trust a G1000. Many glass
cockpits are far too complex and far too poorly tested.

It's odd that pilots would object to a more modern engine on the one hand, but
are more than willing to install the iffy technology of a glass cockpit.

In reality, most piston engines simply require
setting the power for take off, then cruise, and finally descent. It is not
hard at all to do, nor does it add dramatically to the work load (and I have
two engines to consider in my plane).

So losing things like mixture and prop control really wouldn't take anything
away from the pilot, anyway. So why not do it?

Rather than defend or justify Anthony's now increasing list of comebacks and
partial responses, or criticising the other posters, why not answer his
question?

Why haven't you answered the question yourself?