New Cylinder AD's released by FAA

[yr right]

And sir I'm not spreading trash. I'll leave that for yourself. I said I follow the data I'm given and the law that I have to follow. As we'll. you don't and have openly said so on this forum.

And all I've really said I will not advise anyone to operate outside the poh.
Where you have.

Cheers

[Walter Atkinson]

About 40 years ago, TCM (now CMI) ran an IO-520BA on their test cell with no rings installed in any of the six cylinders. It made rated power with a static compression of 0/80. It could only do so for a relatively short time, since it was blowing oil out of the breather rather quickly, but it, nonetheless, made rated power. That's why engines with low compressions due to leaking rings still produce power.

This information came to me directly from the director of the test facility at the Mobile, Alabama, TCM factory. Of, course, that's not "data", it is simply his observation…. oh, wait, that's what data is, isn't it? The observation of a phenomenon and the recording of it during a scientific test.

An opinion is a conjecture without supporting observation during a scientific test. I don't give opinions unless I so state.

[Oracle1]

Dyslexia

No dyslexia here,

And sir I'm not spreading trash. I'll leave that for yourself. I said I follow the data I'm given and the law that I have to follow. As we'll. you don't and have openly said so on this forum.

And all I've really said I will not advise anyone to operate outside the poh.
Where you have.

Cheers

[Lumps]

another wind up

Keep up the good work yr right!

I can't see what good work yr right is doing except for providing us all with entertainment better than anything on TV right now.

As a layman pilot I have read a lot of interesting stuff from the other protagonists, and have read almost nothing of interest or value from our main antagonist. Except, paradoxically, that he has a hangar floor littered with evidence of failed clys from engines that have never failed, not one in flight shut down, nothing etc etc.

Those that hide behind the law (POH?) as holy script can often be left red faced as the law changes when presented with new evidence that replaced previous assumptions. Just sayin'. It happens, even in GA, sometimes.

[Creampuff]

Err, well no, not really. It might be classed as anecdotal, hearsay or maybe even OWT, without a proper, verified source.

Seems to be quite a bit of that put forward in the name of scientific data around here. Keep up the good work yr right!

Some confusion of concepts there.

OWTs are the invalid attribution of causation to (usually perfectly valid) observations and (usually statistically valid) data.

I took 1,000 cockroaches and as I put them on the table I yelled 'run!' I observed that they all ran.

I took the same cockroaches, pulled their legs off, put them on the table and yelled 'run!' I observed that none of them ran.

Statistically valid data and perfectly accurate observations.

I conclude that cockroaches hear through their legs. Invalid attribution of causation.

I took 100 piston aero engines and ran them at exactly the same power settings and operational circumstances for 500 hours. I stripped them down and observed that 98 remained within the manufacturer's specifications.

I took the same 100 piston aero engines and ran them at exactly the same power setting and operational circumstances, except with unleaded fuel.

I observed that most of the engines suffered valve damage within 200 hours.

Statistically valid data and perfectly accurate observations.

I conclude that lead lubricates the valves. Invalid attribution of causation.

[OZBUSDRIVER]

Err, well no, not really. It might be classed as anecdotal, hearsay or maybe even OWT, without a proper, verified source.

Would a "a proper, verified source" be classified as an engine test cell. A cell capable of even verifying an AVGAS replacement good enough for submission for certification?

[yr right]

No data is is what we may use in the course of doing or duties either as a pilot or engineer. Data is what is use for our against you in a court of law.
Now it's your choice how you preform your duties but if you go outside the data them you are on your own. It very simple. And if the poh is changed that's not a problem or an stc is used the same it's then approved data.

It must be approved to be able to be used.

As for me being dyslexic we'll I am affair it's very true. My phone auto corrects there are words you my phone will not pick up and as such I have a weighting style that is a little different. If you can't see that or can't unstandardised that we'll sorry.

I can also say once again I have nothing to do with casa my file has a Red Cross over it with open with caution.

Now of to do sience again.

Cheers

[yr right]

All work is preform with this

IAW

Cheers

[No Hoper]

Ofcourse lead doesn't lubricate the valves, it's the oil leaking past the valve guides
Tetraethyl lead, the snake oil salesman's friend

[andrewr]

Would a "a proper, verified source" be classified as an engine test cell. A cell capable of even verifying an AVGAS replacement good enough for submission for certification?

It's a start. Unfortunately, the history of science is littered with examples where something that worked perfectly in the laboratory and in small scale trials had unforeseen problems in the field.

What you really need is an experiment where you run many engines to TBO, some with LOP procedures, some with the old ROP procedures. The conditions need to be as close as possible to identical for each sample i.e. no significant difference in pilot population etc. You then compare the number of engine problems in each sample.

It's a difficult experiment to run. It needs massive resources. Probably the only practical way to do it would be to put the same engine in different aircraft types, and write ROP procedures in the POH for one, and LOP procedures in another.

Wait a moment - did someone say that some aircraft had LOP procedures in the POH while the identical engine in other aircraft specified ROP procedures? Maybe someone has been collecting data and evaluating LOP vs. ROP results in the field....

What would the results of this trial look like? The conclusion would be something like "LOP procedures resulted in a lower rate/higher rate/no significant change in engine problems reported"

In fact there is a document on the Advanced Pilot web site that quotes Lycoming: "the technique of operating lean of peak and power recovery was discontinued due to the resulting increase in service issues."

To which APS reply "Wrong". Well OK, I guess that settles it...

Just maybe Lycoming are not as dumb as APS like to make out. Maybe they have also tested LOP successfully in engine test cells, but found that it caused problems in the field. Actually, that is exactly what Lycoming say, as quoted on the APS web site.

It wouldn't surprise me if after Lycoming employees go to the APS courses, they go back to Lycoming and someone pulls a folder maked "Lycoming Confidential" out of the filing cabinet. They point out that Lycoming did the same engine tests with the same results 40 years ago, then produce the statistics from LOP field trials which show an increase in problems.

APS claim that extra education and instrumentation are required to run LOP. OK, no problem, but then you need to run another experiment where you compare the rate of problems LOP and ROP with the same level of education and instrumentation. Otherwise, any change could be due to the education, and you are not measuring the effect of LOP vs. ROP.

Science is difficult like that. It is more difficult than just running engines in a test cell. You need expert analysis of the experiment and statistics to see whether they support the conclusions. It isn't clear to me whether APS employ anyone with a science degree, or a statistician.

In summary, I believe that engines can be operated LOP as shown by APS. I believe that they can be very reliable when operated by a fastidious owner.

I don't know whether they will be as reliable when operated by someone who was taught by his instructor who was taught by the flying school owner, who did the APS course but had a little too much lunch and dozed in the afternoon. Or the pilot who knows all about it because they read about it on the internet. Or someone who just follows the POH. Or whether LOP operations might be less tolerant of mistakes when under pressure and you have to make unexpected power adjustments etc. I don't know whether the fastidious owner would get better reliability ROP with the same instrumentation.

The Lycoming quotes on the APS website make me suspect that maybe Lycoming have gathered the data, and they do know at least some of this, and as a result do not in general recommend LOP.

[rutan around]

The Lycoming quotes on the APS website make me suspect that maybe Lycoming have gathered the data, and they do know at least some of this,

Is this the same 'ethical ' Lycoming company that decided it was cheaper to pay out a few grieving relatives than it was to replace the hundreds of dud crankshafts they knew were out in the field? At least it was cheaper until they were sprung.
Also does this all knowing company even have an engine development test cell?

[43Inches]

I have not operated for many companies that have followed the manufacturers recommendations for flight operations to the letter. Most if not all flying training organisations where I've instructed used their own generic check list and procedures handed down over time and incorporated into the Ops Manual, CASA approved. Nothing much has really happened as a result, the issue would only be if you tried to pursue the manufacturer over a problem you caused. As a pilot you get hung for not following the company ops manual and CASA flight rules, the company is responsible for whether the ops manual is correct.

From what I understand the Malibu and Cirrus engines are recommended to operate lean of peak in the cruise. These are relatively new aircraft and may be an indication that the manufacturers are changing their tune.

I would say if operating the engine the way the APS guys say did so much damage then they would have been sued out of existence, especially since their main domain is in the USA.

[andrewr]

Also does this all knowing company even have an engine development test cell?

According to the quote on the APS website they do:

"Lycoming is in complete agreement that it is possible to operate an engine on the lean side of peak TIT. It is done on engines in our well-instrumented Experimental Test laboratory every day. There is nothing detrimental in operating an engine in this manner."

Would you really expect that Lycoming would operate without a test cell?

I'm not saying that they are all-knowing. I'm just saying that it's possible that they know more about the engines they build than APS give them credit for.

I also doubt that they just ship engines out the door and never collect in flight data. I would expect that they work closely with airframe manufacturers, including analysis of in flight data for new or changed installations.

What would be the liability for Lycoming if they didn't? Or for Cessna if they didn't consult with the manufacturer? How would it look in the witness box after an engine failure accident?

[No Hoper]

AndrewR
According to some posters Lycoming and CMI data is OWT and not collaborated by organizations acceptable to APS
and ECi
I agree with your summation of the issue of running LOP in commercial operations, pilots have high enough workload without adding to it

[43Inches]

I agree with your summation of the issue of running LOP in commercial operations, pilots have high enough workload without adding to it

I suggest you go for a fly with a Navajo pilot on a commercial run to see how much workload he's under in the cruise. If they're struggling with the workload at this point they need to go back to a Warrior or something slower. What you will probably see from 10 different pilots is 10 different leaning techniques from peak EGT to 150 rich, to just GPH settings.

[Jabawocky]

What you really need is an experiment where you run many engines to TBO, some with LOP procedures, some with the old ROP procedures. The conditions need to be as close as possible to identical for each sample i.e. no significant difference in pilot population etc. You then compare the number of engine problems in each sample.

American Airlines had 400,000,000 of data collected and ran TBO's several times longer LOP than they or the military could achieve ROP. Deakin San is probably one of the few old enough to remember. (sorry JD )

If anyone had proof of which you seek they did.

[jdeakin]

Good message, incomplete data.

It's a start. Unfortunately, the history of science is littered with examples where something that worked perfectly in the laboratory and in small scale trials had unforeseen problems in the field.

AMEN to that!

What you really need is an experiment where you run many engines to TBO, some with LOP procedures, some with the old ROP procedures. The conditions need to be as close as possible to identical for each sample i.e. no significant difference in pilot population etc. You then compare the number of engine problems in each sample.

It's a difficult experiment to run. It needs massive resources. Probably the only practical way to do it would be to put the same engine in different aircraft types, and write ROP procedures in the POH for one, and LOP procedures in another.

Yeah, but as you say, that's difficult to impossible, and we really don't need it.

Wait a moment - did someone say that some aircraft had LOP procedures in the POH while the identical engine in other aircraft specified ROP procedures? Maybe someone has been collecting data and evaluating LOP vs. ROP results in the field....

The 1985 Turbo Centurion "Information Manual" for the T210R has the following comment on page 4-26:

"The recommended cruise mixture is at peak TIT or 1750℉, whichever occurs first. Leaner mixtures may be used but are not recommended considering that only a very small gain in economy is possible, accompanied by a loss in speed and possibly cabin comfort. However, richer mixtures may be used as desired for smoothness or power at the expense of increased fuel consumption."

Now, the ignorant might say, "SEE, SEE, I told you so, it's right there in black and white, DON'T RUN LOP! And they slam the door of their mind shut. They say you've got to follow that advise to the end of time, OR go through an expensive re-certification process to get it changed.

We (George, Walter and John) look at that language from 1985, and think it's sorta like reading respected (in their day) technical journals that insist the Earth is flat (written a few years earlier).

Now look. The turbo (with the Inconel rotor) will take 1750℉ all day long, but you're asking for trouble with the EXHAUST PIPES, which probably won't. Run it richer or leaner but stay away from 1750. The ENGINE MANUFACTURER doesn't know what kind of pipes the AIRCRAFT manufacturer is going to hang on it.

It does say that LEANER MIXTURES MAY BE USED! It flat out permits it, but offers some caveats. With fuel a $1.00 per gallon, it may be cheaper to throw some more fuel on the fire by running it richer.

"Possibly cabin comfort."

We really scratched our heads over this. What could they possibly mean? I'll tell you, they meant "VIBRATION from a ROUGH RUNNING ENGINE! The factories to this day do not understand the problem, or the simple solution to it! It took the genius of George Braly to produce GAMIjectors, of which there are now over 22,000 engine-sets out there. If all those engines had six cylinders, that's 132,000 individual injectors!

Look at the February 1990 "Maintenance and Operator's Manual" for the TSIO-520-BE engine, for the original Malibu. At high power, the ONLY mixture setting is LOP! IT IS NOT AUTHORIZED TO RUN ROP! IT IS FORBIDDEN TO RUN ROP AT HIGH POWER, BY LIMITATION!

I'll give you a hint. There is one minor adjustment to the engine that turns it into a LOP-ONLY engine. Does any know what it is?

In fact there is a document on the Advanced Pilot web site that quotes Lycoming: "the technique of operating lean of peak and power recovery was discontinued due to the resulting increase in service issues."

What were these "service issues?" Engine roughness when LOP! We say fix that, and you can run LOP again. Lycoming did not know how, because they did not, and do not understand why the engine runs rough.

It isn't clear to me whether APS employ anyone with a science degree, or a statistician.

George happens to hold an Aeronautical Engineering Degree from Brown University. When he graduated, AEs were plentiful, and jobs were very scarce. So he went back to college, and got a law degree as well. He put himself through both by Flight Instructing. His first aero job was with Ted Smith aircraft, builder of the Aerostar. His initials are on the original drawings used to build that airplane.

In summary, I believe that engines can be operated LOP as shown by APS. I believe that they can be very reliable when operated by a fastidious owner.

Thanks. I'll quibble a little bit, because IF AN ENGINE CAN BE OPERATED LOP, it's easier to do so, and a good deal safer, with OR WITHOUT an EMS.

John Deakin

[andrewr]

American Airlines had 400,000,000 of data collected and ran TBO's several times longer LOP than they or the military could achieve ROP.
If anyone had proof of which you seek they did.

Ah, that old chestnut. It's misleading to claim the old radials are the same as a Lycoming. Sure, they work on the same principles and use similar materials, but so does an aircooled motorcycle engine.

Some things which might be different, which may or may not make a difference:

• combustion chamber shape
• combustion chamber volume
• compression ratio
• valve timing
• ignition timing
• duration of the power stroke
• fuel specifications
• frequency of power changes
• power settings used e.g. maximum range settings

What manifold pressure did they run? Can I run that in an IO360? If not, maybe not all the operating parameters are directly transferable.

[Walter Atkinson]

***
Ah, that old chestnut. It's misleading to claim the old radials are the same as a Lycoming. Sure, they work on the same principles and use similar materials, but so does an aircooled motorcycle engine.

Some things which might be different, which may or may not make a difference:
combustion chamber shape
combustion chamber volume
compression ratio
valve timing
ignition timing
duration of the power stroke
fuel specifications
frequency of power changes
power settings used e.g. maximum range settings
What manifold pressure did they run? Can I run that in an IO360? If not, maybe not all the operating parameters are directly transferable.***

No, actually the motorcycle engine is the different one. Mainly due to the shape of the combustion chamber. All of the above issues are so close between the radial and the flat engine as to be non-issues. The truth is, that the radial is a bit tougher to run… mainly because the detonation margin is narrower than your 360. They both run under very similar ICPs which is the big issue.

[Jabawocky]

andrewr

The list of differences is almost nothing compared to the similarities. The fuel and oxygen do not know any different. The motorcycle engine is not that much different at all apart from chamber shape, but remember they are designed for vastly different rev ranges. Otherwise, the rest not much in it.

The big turbo radials ran a lot more MP, but that only means reduced detonation margins to your trusty 360.

Why not come along and learn why?