Extended full-power in small pistons

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.

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.

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.

But automobile engines require virtually nothing in the way of certification.
This has become apparent in some cases when computer controls added to engines
have misbehaved, because manufacturers never bother to design and test them
adequately. The consequences of that would be much worse in the air.

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.

wrote My favorite?

When he said he saw no difference between my vidoes posted on You Tube
and MSFX.

Yep. that's "special," no doubt.

One of the insights into his mind came when someone posted links to his
blog, and he wrote on and on about going places, to pick up his imaginary
passengers, to fly to imaginary destination, and then having to wait around
the airport until his passengers came back to leave.

He "really" thinks simming is just as good as going places, and better,
because it is less expensive, and safe. Reality, to him, is just a passing
introduction, but he has never become friends. Wow.
--
Jim in NC

Viperdoc wrote:
Anthony:

You are wrong again- which cylinder are you monitoring when you watch the
EGT? How about the CHT? Real jet pilots do more than push the levers forward
as well- just because you don't know or understand doesn't make it any less
important.


Well actually you don't really do much more than that, actually most of
the time you don't even do that on modern jet engines apart from monitoring.




Managing and monitoring the engines are part of flying, not a hazardous
distraction- you simply don't understand and are trying to extrapolate your
lack of reference to actual flying.

Well still taking away workload from the pilot is not such a bad thing,
especially when flying single pilot in bad weather or other stressy
situations, and the trend on modern engine is toward that with
electronic engine management.

Clark wrote:


As Viperdoc said, setting the engine is part of flying. We learn it from
lesson one which, by the way, you've chosen not to take.

We spend countless hours learning how to fly and manage the aircraft. Why
do you think a question on usenet and a toy simulator can even begin to
relate to that? Go back to your sim world and stay the hell away from here.


As I said answering to Viperdoc, the trend is towards relieving the
pilot of the workload of managing the engine, which is not a bad thing.
It is true that with modern engine technology the aviation piston engine
is a bit behind times

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. 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).

Turbines have even less to control, but perhaps a few more dials to monitor.
It is all part of flying.

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?

Anthony:
You are wrong again- most of the avionics in private planes are well
advanced over those found in airliners (ever see the cockpit of an MD-80
compared to a G-1000 Bonanza, of course not).

Your comments about soaring are also specious- you even know less about
gliders than powered flight.

Actually, your premise about babying an engine may not be true. Is there
data that supports this "gentle" use of an engine adds to longevity?

My own plane, as well as others with the same type (an Extra 300) are
essentially operated in an on/off mode. It generally is full power (2700RPM
and full throttle) on TO, cruise to the practice area, and then on/off, with
no regard to shock cooling or heating- full power straight up, power off to
spin, then full power on the recovery. Gyroscopic maneuvers (with a
composite prop)- no problem with cranks.

Yet, with 400 hours of this operation on my plane (and many/many others
according to the reps), none have required an overhaul, with some up to
1,000h of similar operation.

Likewise, Lycoming and Continental always gave some hand waving response to
questions about running LOP, yet, Cirrus, with now many thousands of hours
of LOP operations now mandate operating in this realm.

So, a lot of what is considered "safe and prudent" operating may be more of
an old wive's tale, and not supported by actual data.

Viperdoc wrote:
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.

The old argument. Interesting, though, that modern car engines are much
more reliable than older (simpler) ones.

On Jan 3, 9:21*am, "Viperdoc" wrote:
Actually, your premise about babying an engine may not be true. Is there
data that supports this "gentle" use of an engine adds to longevity?

My own plane, as well as others with the same type (an Extra 300) are
essentially operated in an on/off mode. It generally is full power (2700RPM
and full throttle) on TO, cruise to the practice area, and then on/off, with
no regard to shock cooling or heating- full power straight up, power off to
spin, then full power on the recovery. Gyroscopic maneuvers (with a
composite prop)- no problem with cranks.

Yet, with 400 hours of this operation on my plane (and many/many others
according to the reps), none have required an overhaul, with some up to
1,000h of similar operation.

Likewise, Lycoming and Continental always gave some hand waving response to
questions about running LOP, yet, Cirrus, with now many thousands of hours
of *LOP operations now mandate operating *in this realm.

So, a lot of what is considered "safe and prudent" operating may be more of
an old wive's tale, and not supported by actual data.

You could be right. Never the less, our TBO is determined by tach
hours, and we are happy to run at 1950 at altitude instead of 2600. It
could be a old wives tale, but rapid temp change does different things
to metals than does more gradual changes as well. We'll continue to
fly with a gentle hand -- it pleases us to do so, even if there's a
possibility it doesn't prolong engine life or reliability. I am pretty
persuaded it does, but can offer no evidence. It would be interesting
to have a mechanic examine enough engines flown with different flight
algrithyms to see if he could detect a difference or estimate service
life -- a single blind protocol, if you will.

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

Likewise, Lycoming and Continental always gave some hand waving response
to
questions about running LOP, yet, Cirrus, with now many thousands of hours

of LOP operations now mandate operating in this realm.

So, a lot of what is considered "safe and prudent" operating may be more
of
an old wive's tale, and not supported by actual data.

You might want to read through this article:

http://www.lycoming.textron.com/supp...es/SSP700A.pdf

Scott Wilson