C210 down in Broome town

[Trent 972]

Creampuff said ...

An in-flight magneto check, LOP at altitude and high power.....

Please O Great Wise One, pray now tell me what you would do if you discovered at that point an electrical systems was dead. Would you reselect it back to the live system at that HIGH power setting?
I'm guessing with your past history of gear and flap switch cockups you might just do that.
Let Jabba do the educating, because you are hopeless. Stick to your legal stuff. At least you know what you're talking about there.

[Agrajag]

At the end of the day I really don't care if you run lop. It's your plane unless you hire one then it the wiener that will dictate what to use. However if you think your lame not going to notice well I think you deluding yourself. If you think a lame going to turn a blind eye because you have damaged your engine and he is going to sign it off against the AD ( which is law) and against the manufacturer it's not going to happen. Then depending on how much damage you have done how much fuel saving do you have to do to have that return.

...a-a-a-and here we go again. I'm sure Creampuff and FTDK need a break by now, so I'll weigh in.

Yet again you make unsupported assertions, in the face of many, many explanations to the contrary. But I'll have another go:

1. If LOP = engine damage, please explain the mechanism by which it does so. By this I mean, give us the blow-by-blow of what takes place during and after the combustion cycle in order to bring about this damage. APS provides this sort of analysis during their courses. If you are to dispute their data, you need to provide a similar depth of explanation. Simply claiming "it burns valves" or "it damages cylinders" won't suffice.
2. LOP operation is not carried out as a means of saving fuel. That's just a happy by-product. The real reason for doing so, is that the engine runs cooler and with less stress.
3. Instead of focusing on the engines allegedly damaged by LOP operation, how about looking at the vast majority which weren't? I have personally spoken to one high-time IO-520 operator whose first two engines failed to make TBO, in spite of receiving top overhauls partway through their lives. The third engine went all the way, with no top overhaul. There was only one change in operating practice with that engine. I'll leave you to guess what it was.

If you believe the hype how America airlines extended there engine overhaul life by running lop go find out the original overhaul life for those engines. The hardest part of an engine life is take off. Dose the engine destroy its self of
On takeoff with high temps cylinder pressures and everything thing else they profess. No they don't.

You're not going to get away with that one either. During takeoff those big engines are running well on the rich side of peak; in fact as rich as they will go. And the kind of power they're developing is only allowed for 5 minutes, 10 in emergency. That's hardly representative of the majority of the engine's life.

As to the comparative overhaul lives before and after LOP was instituted, that's well documented. Off the top of my head, I think they went up by a factor of about 10. Of course the operators didn't know they were running LOP at the time, but they were doing so regardless.

With the new instruments that are available everyone is now an expert. However they not.

By your logic, the less we know about what's going on inside our engines, the better off we are. That's just ludicrous. With this sort of data now available, we can get a very accurate correlation of cause and effect, every time we operate the engine. And with a bit of education, we can interpret the information to achieve desired results.

I'm really sorry if you feel this encroaches on your monopoly of knowledge about how engines work. But those of us who fly them have a far greater investment in their reliable operation than anyone who doesn't. It's not adequate for any responsible pilot to regard what's going on ahead of the firewall as some mystical zone, with access to its secrets allowed only to the chosen few.

In this business, as with many others, knowledge is power. Anyone who wants to restrict or constrain that knowledge is derelict in duty at best; dangerously irresponsible at worst.

[Eddie Dean]

Typical Ppuner argument there Agrajag.
Decry another's argument as unsupported assertions by supplying your own unsupported assertions.

So in your own time explain how TBO is achieved in Bell 47-3B1 engines when mixture control was removed from them many years ago.

Cheers

[Creampuff]

Please O Great Wise One, pray now tell me what you would do if you discovered at that point an electrical systems was dead. Would you reselect it back to the live system at that HIGH power setting?

Although I'm not wise, I have enough knowledge to know that magneto checks have nothing to do with "electrical systems".

I realise your (rather odd) obsession with trying to find anything and everything wrong in my short posts about complex subjects skews your thinking, so I realise you made an inadvertant mistake in what you typed. What you meant to ask was would I select the good magneto back to on, having discovered that the magneto I am on is "dead".

Those who are willing to learn and have learned will know that the very complicated procedure on discovery that a mag to which you've switched is "dead" is to:

(1) pull the mixture to idle cut off; and
(2) select the good mag, or both, if it was working on both; and
(3) return the mixture to its previous settings.

Last time I did it, the wings dropped off (of course).

Disturbingly, I'm not sure whether this is taught adequately as part of the standard "rough running" checks people are trained to do when they are forced to do an in-flight mag check.

My post was in response to someone who suggested an in-flight mag check is something that shouldn't be done at all as a normal procedure.

I'm guessing with your past history of gear and flap switch cockups you might just do that.

What fascinates me is the apparent correlation between the ppruners who appear to believe they've never made a mistake and the ppruners who come across as complete idiots. Not sure (yet) whether it is, in fact, causation rather than correlation.

Let's make it rule that only those who've never made a mistake while aviating get to post on pprune. Deal?

[Agrajag]

Typical Ppuner argument there Agrajag.
Decry another's argument as unsupported assertions by supplying your own unsupported assertions.

Unsupported? Sorry, but I'm guessing you're new to this topic. The supporting data on my side of the discussion has been out there for a long time by now, and doesn't need rehashing.

So in your own time explain how TBO is achieved in Bell 47-3B1 engines when mixture control was removed from them many years ago.

Don't know; never flown one. But I suspect the default setting was made so rich that the engine couldn't get anywhere near the "red box". I just can't imagine any Bell 47 being equipped with the engine monitoring technology we now have, or that the pilot would have time and spare limbs to make use of it if it were.

[Eddie Dean]

(1) pull the mixture to idle cut off; and
(2) select the good mag, or both, if it was working on both; and
(3) return the mixture to its previous settings.

Mmmm - what about hitting the crank button whilst saying a prayer to the God of your choice

[Tankengine]

Probably because hitting the "crank" button might stuff the starter motor or ring gear as the engine would still be rotating.

[Eddie Dean]

You think so Tanker, two inflight shutdowns I've done have resulted in a stopped engine/propellor

[yr right]

So once again an omg. You do a mag check at low revs for one simple reason. So you don't induce cracks in the crank.
Clinton you didn't answer the question I ask u previously. When you land your aircraft what is the first thing you do.

[Creampuff]

I cannot follow the rest of your proposition.

Does a Doctor wait until someone's had a heart attack to come to the conclusion that the person has a cardiovascular problem?

Most cardiovascular failures, like most ignition system failures, are caused by problems that start small and get bigger, but can be detected and addressed when they're small. That's why doctors check, among other things, your blood pressure. In some cases your doctor will connect a bunch of wires to you and put you on a treadmill.

A "healthy" piston aero engine with duplicated, "healthy", ignition systems is able to run at high power on one of those systems. Indeed, if it's a certified engine, it's part of the certification basis.

When your engine is at high power at altitude, it's on the cardiovascular version of a treadmill. If you have an engine monitor connected to it, you're measuring many of its vital signs.

If any part of your ignition system has any small problem that is slowly getting bigger, the most likely time at which it will first manifest itself is at high power, high altitude, LOP. The most effective way to narrow the problem down is to run each mag separately in those conditions.

(Other developing problems, like small changes in static timing, will often first manifest themselves in unusually high CHTs at high power during climb.)

These problems can be diagnosed and fixed before they become the equivalent of a heart attack.

The most recent real-life in-flight ignition system problem I had only manifested itself at 9,500'. I diagnosed the problem with a magneto check. The problem disappeared passing 8.500' on descent and the system tested perfectly on a "standard" ground magneto check. But the problem was still there, was fixed, and therefore was prevented from getting any worse and doing more damage to the ignition system.

Almost all ignition system problems don't need to be left to develop to such an extent that an engine "fails" a "standard" ground magneto check. Once it's got that bad, it's almost certain that the engine hadn't been performing as well as it should have, for a long time beforehand.

In the case of the perceived risks of doing an in-flight mag check that shows one magneto is "dead", think about how it's possible for the aircraft to have got to that state in the air in the first place, without the pilot knowing. If it's really the case that the aircraft had a genuinely random in-flight failure resulting in a completely dead magneto, even an aircraft without an engine monitor is going to "tell" the pilot something is "not quite right". And then the pilot's going to do, what? A mag check, among other checks...

But I get it now: It's dangerous to do an in-flight mag check on an engine whose monitor and trend data shows it's currently healthy, but not dangerous to be blissfully ignorant of the fact that you're flying along with a "dead magneto".

Eddie: what type of engines fitted to what aircraft, precisely, stop rotating in flight when the mags are switched off or the fuel runs out? I'm yet to find any aircraft piston engine that can be stopped rotating in flight, other than by switching off the mags or fuel and stalling the aircraft.

[Trent 972]

Creampuff, do you get your little wisdoms from Savvy or the like.
Perhaps this procedure they advocate is what you're on about.

In-Flight Lean Mag Check
The in-flight lean mag check is a test of ignition system performance, and is used to help diagnose problems with magnetos, ignition harnesses, spark plugs, ignition timing, etc.
Perform the in-flight lean mag check procedure by setting up the airplane in normal cruise on autopilot. Then perform the following procedure.
 Lean to an aggressively lean cruise mixture. The leaner, the better for this test. The test will be much more discriminating and meaningful if you lean to a lean-of-peak-EGT (LOP) mixture setting. Preferably lean as far LOP as you can without experiencing significant engine roughness.
 For a key or rotary style magneto switch (as found in most singles), select BOTH-LEFT- BOTH-RIGHT-BOTH, leaving the mag switch in each of these positions for one full minute.
 For individual magneto toggle switches (as found in most twins), turn off the LEFT ENGINE/LEFT MAGNETO switch for one full minute, then turn it back on and wait for one full minute. Repeat this procedure with each of the other three magneto switches in sequence. (LE/LM, LE/RM, RE/LM, RE/RM.)
NOTE: It is normal for engines to run a bit rougher on one magneto than they do on two, but they should not run change-of-underwear rough. Please report on the level of perceived roughness during phase of the test.
NOTE: For turbocharged engines, TIT may rise to above red-line during single-magneto operation. This is normal and will not do any harm if the exceedences do not exceed a few minutes’ duration.

Not too sure if the 'Note' at the bottom of that procedure would gain the Engine OEM's agreement. Perhaps the whole procedure is flawed. I'm not educated sufficiently enough to know. Are you?

[Pontius]

You think so Tanker, two inflight shutdowns I've done have resulted in a stopped engine/propellor

Eddie: what type of engines fitted to what aircraft, precisely, stop rotating in flight when the mags are switched off or the fuel runs out? I'm yet to find any aircraft piston engine that can be stopped rotating in flight, other than by switching off the mags or fuel and stalling the aircraft.

I'm also interested in Eddie's answer to this and, just to clarify the rules of engagement, feathering a prop and it no longer rotating in the breeze does NOT count as "a stopped engine/propellor".

[Eddie Dean]

That is my point Creampuff, if both mags are off, grounded, the engine stops.

[Creampuff]

I get my knowledge from the data published by John Deakin and the other APS people.

No, I'm not sufficiently educated.

It is astonishing, though, that despite everything advocated by APS (and "Savvy", whatever or whoever they may be) contrary to OEM publications, they've never been sued for giving negligent advice. I wonder why, given that they live in the land of litigation at the drop of a hat. (Actually, I don't wonder why...)

[Virtually There]

Interesting discussion. But is fuel really that cheap compared to the cost of an engine?

The difference in fuel burn between max power (ROP) and max economy (LOP) is about 20%, or 10 litres an hour in an IO-520. That's $40,000 for a 2,000-hour overhaul at today's fuel prices - the cost of a factory refurbed engine.

Simplistic (yes, unrealistic) figures, of course. But saving even a fraction of that amount puts things into perspective. Fuel is the biggest expense of running an aircraft and the one thing owners/operators have a degree of control over.

[Creampuff]

That is my point Creampuff, if both mags are off, grounded, the engine stops.

C'mon Eddie, stop evading the point of the question you're purporting to answer.

What type of engines fitted to what aircraft, precisely, stop rotating in flight when the mags are switched off or the fuel runs out? I'm yet to find any aircraft piston engine that can be stopped rotating in flight, other than by switching off the mags or fuel and stalling the aircraft.

This thread is about a Cessna 210. This "discussion" arose out of speculation about the cause of the forced landing of a Cessna 210 and, consequently, fuel management on a Cessna 210.

If you are talking about toys or those devilish contraptions, helicopters, just say so please.

[Pontius]

That is my point Creampuff, if both mags are off, grounded, the engine stops.

Well, it may no longer be producing power but all the bits inside the engine continue to go up and down and round and round, assuming the propellor is not feathered and the speed is sufficient to rotate it. To get the engine going again is just a matter of getting a spark and some petrol doing their thing and certainly not "hitting the crank button whilst saying a prayer to the God of your choice".

A mechanical failure will stop an engine and no amount of "hitting the crank button" is going to get it going again. An engine failure caused by fuel or electrical problem can be solved by restoring the missing element and then maintaining sufficient speed such that the still-rotating propellor 'cranks' the engine or by un-feathering the same.

In my experience the only time the propellor stopped (in a Chipmunk with a self-induced fuel problem - mixture FAR too rich) was when I slowed to the best gliding speed. Having diagnosed and remedied the snag it was simply a matter of lowering the nose to get the speed up and propellor turning and all was well again. Luckily no "hitting the crank button" was required because that involved a cartridge start

[Eddie Dean]

Well for me. I'll buy the next round as penalty.
The two times I saw shut down was Nomad and an Islander, both feathering props of course.

[Tankengine]

Just how many mags does a Nomad have?

I can assure you, pulling the mixture or turning off the mags will not "stop" most piston engines unless you are close to stall speed!

Of course the Islander is always close!

[Pinky the pilot]

Just to be slightly difficult; I had two occasions flying Islanders where I had to feather the prop and shut down the engine due to severe loss of oil pressure, the first occasion being a failure of the vacuum pump oil seal, the second being a catastrophic engine failure.

On both occasions the prop did not move to a fully feathered position and at single engine cruise speed (really cannot remember now but must have been about 85KIAS) the prop still flicked over a half or so a turn every 15 to 20 seconds!