Engine Rumour
 

A rumour at the airfield today that CASA is withdrawing engines on condition for those currently approved and going for ten year overhauls. Has anyone else heard this?

One way to start a war!

This rumour has the ring of truth since there is at least one moron in CASA who already thought up and promulgated hard time propeller overhauls as well as control cable replacements.

These actions might be necessary but only on the basis of a major research project that:

(1) Examines a statistically valid sample of of engines, propellers, cables, etc., then,

(2) Produces a statistically valid relationship between component age and catastrophic failure probability, and finally,

(3) Mathematically tests the hypothesis that "there is an X% probability that catastrophic failure will occur after Y years", then

(4) model the expected change in failure rates as a result of proposed regulation, taking into account costs and appropriate risk management principles.

The final step (4) needs to also account for "infant mortality" which in my opinion is not inconsiderable when it comes to engines and other components, where the simple acts of removal, overhaul and reinstallation introduce more failure points.


And finally if all this work had been done,, which it hasn't, and supported the current CASA conclusions, which it doesn't, then the FAA would have mandated the replacement or overhaul periods at least Fifty years ago, which it didn't.

Speaking as someone who did this type of work for Six years at Ansett, by hand without benefit of computer, in the old days.

"then the FAA would have mandated the replacement or overhaul periods at least Fifty years ago, which it didn't."

Because Sunny the FAA completed your points 1 to 4 as a proper regulator with "Foster and Promote" in their charter and concluded it wasn't necessary.

I understand the statistics bear that out, with more catastrophic failures from overhauled engines than those on condition.

Then by and large the FAA employs "Competent" people not dross from the bottom of the gene pool who are legends in their own minds.

My father always said when I learnt to fly, "When you think you know it all give it up and do something else". Unfortunately our ex military and failed industry masters have nothing to learn about aviation, the rest of the world knows nothing about aviation, CAsA is the font of all knowledge and their Philosophy of " Better to die safely than live non compliant"

Those that can, do; those that can't, teach; those that can't do or teach, go to CASA. :}

If CASA go to hard time engine overhaul, the price of scrap aluminium will drop remarkably.

.......

...........

...........

.........

Or Dulux Overhauls will become very popular! :eek:

I seem to remember they (CAsA) tried this on in the mid 90's with a 12 year limit and it was suitably knocked on the head very quickly. I don't recall the name of the turkey behind it but he hasn't been heard of since (mercifully).

CC

Originally Posted by wishiwasupthere http://www.pprune.org/images/buttons/viewpost.gif
Those that can, do; those that can't, teach; those that can't do or teach, go to CASA.

Mostly said by those who have never taught and can never learn.

I used to do.....
Now I teach.......

I can tell you which ones harder......

If CASA bring in a mandate to overhaul at 12 years you can be assures that all my skills doing/teaching and understanding the Regs will go to stop this. Just as I did with the ridiculous prop AD amendment.

Obi_wan: LAME's are not "out on a limb" on this one. CASA provide clear guidance on the actions to be taken to continue an engine on condition in AWB 85-004 - issued more than 10 years ago.

The key to operating an engine on condition is to start early in its life with oil analysis/trend data gathering, a fact lost on many owners who want to begin "on condition" monitoring on the day it reaches TBO.
Would I sign out an engine on condition the first time i had seen it - NO, if it had full records of its operating parameters, a long history of SOAP analysis with no major changes and I had completed the checks in the AWB - Absolutely.

If engines are failing while on condition the next question asked should be "Are LAME's following AWB85-004 and is it adequate" My guess is many LAME's are not following it.

The problem isn't on condition engines, it those owners that do very few hours and just think an engines inner workings are fine.

I worked for a company that had a large number of Chieftains that were allowed to over run their TBO by hundreds of hours with little issues. but these engines did regular and consistent flying with proper trend monitoring.

Yet on the same airfield I knew of one single beech that did around 50 hours a year and the owner wanted to have his engine on condition when it reacheded it's calendar life. Not an aircraft I'd like to fly.

It is these owners that forces CASA to act in the manner it does and will for piston engines. However TBO extensions for turbines are much easier, mostly because the manufacturers recognise those operators who have implemented programmes of trend monitoring, regular boroscope inspections and regular oil analysis.

It would be great if CASA went back to allowing TBO over runs on Pistons under strict programmes such as above, but we will never see those days again.

Welcome back yr-right.


Meanwhile, a couple years ago, the CASA crew came to our patch to talk ageing aircraft, and here it was mentioned about 12 year overhaul life possibility, regardless of hours flown (up to published TBO)
The 12 years come from Lycoming Service Instruction 1009AV.
Lycoming Recommendation. Which in many CASA eyes = Mandatory, despite recommended and mandatory being two totally different things in the real world.


I know of a 40+ year old Arrow, still on the original low hours engine. Still checks out fine every year by a very reputable shop.

dh pilot is on the money IMHO. It's the private aircraft that sit around and do little if any flying that are at high risk, due to internal corrosion and seals/hoses drying out.

Other issue that annoys me, is that there is no way I as a private hirer can determine if an engine is on condition or not, without asking the LAME or owner. The MR should clearly state if the engine/s are on condition. I have addressed this issue with CASA which went on deaf ears.....

Sure about that obi? Not from what I have seen and it's certainly not a CASA requirement from what I have been advised.

Happy to be corrected, a reg number would also be great as I will take a few people to task if what you are saying is true.

Great to see you guys are being very proactive on this obi, obviously some other LAMEs aren't. If there is no regulatory requirement, why should they I suppose - not ideal however that's the world we live in.

Get what you pay for, and looking at some of the junk flying around I'm surprised that there aren't more accidents. Not being an aircraft owner and sometimes being forced to hire junk, I elect to do something else other than flying when the numbers don't line up.

obi_wan2015

Sorry, I don't remember that.

CC

If the rumour's true, it would be another mule-stupid but depressingly-unsurprising decision, given the increasingly mule-stupid regulatory regime strangling GA in Australia.

The most common cause of catastrophic piston engine failure is poor manufacture, assembly or maintenance - so called 'infant mortality'.

Once an engine has survived infancy after manufacture or maintenance, the most effective way to prevent catastrophic failure is to have a good engine monitor, know how to use it, know what it's saying and know how to run the engine properly. That will reduce the scope for operator-induced problems and identify trends that can be addressed well in advance of any serious failure.

I'd much prefer flying behind an on-condition engine with an engine monitor, than a new engine without. That's because I'd be safer.

But why bother regulating, maintaining and operating on the basis of objective data and objective risk management? Let's all refuse to fly on-condition engines until the regulator saves us from them. :ok:

I know of one aircraft that was running on condition with no problems. Due to grumbling of the LAME and the notices on the MR, the owner replaced the engine. Within a short time, the new engine had metal in the filter. It was replaced under warranty, but I believe they also had problems with the second new engine.

When LAMEs talk about liability, I think they need to look carefully at what actions actually create the most liability for them. My understanding is that most liability comes where the owner relies on your advice and expertise, and for work that you do.

If an owner says that they want to run on condition and there is no problem with the engine that would prevent that, the LAME might be held responsible if they advise against it. If the new engine fails and an accident occurs all it takes is some expert to come in and say "It has been known for 50 years that failures are more likely after maintenance and particularly in the early period of an engine's life. The TBO is only a recommendation based on a conservative guess at the engine's life. An engine that has been running for years without problems is less likely to fail than a brand new engine. If it wasn't for Mr X's advice to replace the engine, it is likely that the deceased would still be alive today" and the whole thing ends up on the LAME's plate.

If the owner makes the decision to run on condition and an accident occurs, the LAME can say "He knew it was past TBO, but made the decision to operate on condition. When we inspected the engine it met all the parameters for continued operation." In that case the responsibility is squarely on the owner/operator.

Mandatory replacement at TBO would be good and bad for the LAME. It removes their responsibility for the advice to replace the engine. (For the purposes of the regulations, CASA can probably assume that engine manufacturers and LAMEs are perfect and infant mortality doesn't exist.)

However, if the concept of infant mortality holds true, it probably increases the overall risk of engine failure. Those failures are then blamed on either the installer (LAME) or manufacturer. It can't be the owner because the engine is new, right? So you have more engine failures, with LAMEs fighting with the engine manufacturer over liability...

Interesting discussion, however we need to see a detailed safety case and evidence to justify any change whatsoever. A change to ENG/4 would be a political nightmare especially after all the new words from the DAS, promoting a new culture etc. Seems to be a sign the Iron Ring is still there...?
I have no doubt that such a change without appropriate justification would be on the PM's desk in a flash, pushed by over 50% of GA owners. As I said, it would be war....

I'm sure that if 'obe_wan2015' is a LAME, then he has no comprehension of how modern engine monitors actually work. And the wealth of information that, properly used and analysed, they provide to pilots.

Let's imagine that a fictional pilot is flying a Bonanza with a serviceable engine monitor fitted. In cruise, his Continental IO520 suddenly shows a slight issue with No 3 cylinder. That might be heard as a minor misfire, for example. Initial signs are EGT and CHT temperatures that are out of whack with the others. This fictional aircraft owner has gone to a lot of trouble to learn how his engine actually works. He's long since realised that some of the engine instruction that he learned 30 years ago is complete rubbish.

So he attempts to do a bit of fault finding in flight. He knows that each cylinder has two spark plugs. And that each cylinder is powered by different magnetos. He narrows down the fault to a fouled sparkplug. But which one is it? He's at 9500' with a suitable aerodrome 5 nm away. So he uses the Magneto switch to solve that question. (He knows which magneto is hooked up to which sparkplug.) After landing, he changes the offending sparkplug as he's legally allowed to do that. And he happens to carry suitable spares and tools.

And to the delight of his pax, they then head off on their way. :)

None of you need to get into a shyte fight.


What you want to see is rigourous, detailed and comprehensive research that proves incontrovertibly that replacing an engine at Ten years across the entire Australian piston fleet will reduce the cost and risk of fatality to Australian aviation.

Contrary to popular belief, actuaries can and do put a price on human life.

Risk management computes the total cost of a risk reduction strategy in dollar terms, the includes the increase in motor traffic deaths as a result of reduced flying passenger hours, the cost of engine replacements and the cost of accidents that can be attributed to engine failure asa result of o condition engine failures.

FIrst cab of the rank is to compute in flight engine failure rates of on condition and hard time engines. I would be surprised if there was much difference. I would be further surprised if OC engines had a statistically significant higher rate per thousand hours flown.

If you were a pilot you'd know that the book you worship requires them in some circumstances. And if you had any capacity to learn and reason logically, you'd understand why an in-flight mag check on a conforming engine is a complete non-event.I can organise an oil analysis and do other inspections without the 'benefit' of your input, thanks very much.

And what would the most likely cause of the break up of a bearing or cam lobe be? Bad manufacture or incompetent maintenance. The reliability of ELTs after a crash is shown by the data. But we already knew that you are incapable of learning from data. Must be busy being an expert on piston engines and civil law. Where did you get your degree and when were you admitted to practice?And when the last of the GA owners give it up because of this mule-stupid lowest common denominator system, I will mourn the loss of work to the good engineers in the system. And you sure ain't one of them.

Folks,
Just to remind the man with the "light sabre" complex, US (at least) engine manufacturers do not publish TBO, they publish "recommended" TBO, a not very subtle difference.
As for FAA requirements (after all, the number of aircraft in the US makes for statistically significant data) see the regulations applying to type of operation, ie: Part 91, 125, 135 etc.
Tootle pip!!

We do it every time we go flying.

And we know why you don't understand that.

And you're living in blissful ignorance, believing that stopping on-condition maintenance is going to stop someone taking you to court.

Lighten up obi. Anyone would think you were curing cancer or something!

Some people in this industry seriously have a severe case of figjam.

Running a spell check wouldn't hurt either.

obi_wan2015 clearly went to the same school as yr right. Or they're related. Or yr right has been reincarnated just like the original obi wan! I'm sure that ridiculous writing style is done deliberately to annoy everyone else. If so, its certainly working a treat with me..!:ugh:

Then don't do it.

Get it?

Just don't do it.

You'll feel better and we won't have to wade through your waffle to get to the important stuff.

And the really dumb thing is that you will be blissfully ignorant of your exposure when you fit that new engine in accordance with the manufacturer's recommendation. But clearly, blissful ignorance is your area of expertise. :ok:

I don't know why casa bothers about TBO's . When you think about it every engine flies 'on condition'. If a 1800 hr TBO engine chucks a con rod through the block at 50 hrs you don't just carry on for another 1,750 hrs because casa said it should be good for that time.

It all comes down to the mode of failure in high time engines. If impending failure gives plenty of warning then why not run them till you get tired of topping up the oil.

It appears that catastrophic failure is much more likely to occur early in an engine's life or as a result of maintenance errors than it is due to high time.

Even underutilized engines generally do not fail catastrophically. They simply wear out quicker than frequently used engines.

If casa wants to do something to help GA it would be better employed tuning up the suppliers of aviation parts and supplies. In my association with aviation I have survived the biggest fuel contamination scandal to occur anywhere in the world, TCM cylinders belling out the tops of their cylinders, Lycoming killing people with dodgy crankshafts, TCM neglecting to do adequate quality control resulting in a rash of improperly case hardened followers and thus ruined cam shafts. Now we have TCM selling new cylinders which don't seal properly brand new from the factory causing more expense as Aust engine rebuilders have to check all of them and reseat many. These are just problems that have affected me . There are plenty more.

All of the above list has cost operators collectively millions and what happened to the perpetrators ? nothing ? a slap on the face with a 3 day old lettuce leaf ? Not much that's for sure because every couple of years they manage to inflict some new expensive,dangerous blight on our industry.

Oversight of these companies by casa with half the enthusiasm they they have for trashing perfectly good engines would bring about a safer, more affordable and happier GA community.

Rutan around:

And think of all those lovely overseas conferences and fact finding missions such a policy would generate…...

Where did 10 years rather than the Usual manufacturers' 12 come from?

Are CASA just trying to make sure we're really really really safe? Yes, I guess so. Pricing GA operators out of the industry for no particular safety benefit should be in their vision statement.

You just don't get it, obi. But that's understandable: You have a very narrow experience that just happens to be repeated over and over.

Who is it that signs for and takes responsibility for the daily inspection? Not the engineer that signed the MR. As rutan around has pointed out, the fact that some LAME has signed an MR does not absolve the pilot from responsibility for spotting the loose spark plug lead, or that 9 quarts of oil had been added by the LAME without draining the old stuff and changing the oil filter, or the undercarriage circuit breaker that's pulled, or the ....

(When is it that pilots find the most things wrong with an aircraft? In that inspection and flight just after some LAME signed the MR.)

Who is it that has responsibility for the weight and balance calculations and loading distribution for the flight? Not the engineer that signed the MR.

Who is it that has responsibility for the fuel load and calculations? Not the engineer that signed the MR.

Who is that has responsibility for the landing and take-off distance and obstacle clearance calculations? Not the engineer that signed the MR.

Who is that has responsibility for reviewing and planning around the weather forecasts and NOTAMS? Not the engineer that signed the MR.

You're as bad as AVMED. You have this messianic belief that you and the manufacturer's recommendations and pieces of paper are the only bastions against aviation death and destruction. (Actually, you're worse, because you don't have the capacity to comprehend that you're at higher risk of liability when you 'sign out' a new engine than you are when you sign out one that's on condition.)

When the weather turns bad or a magneto fails because of some dodgy spark plugs fitted by some narrow-minded LAME who takes as gospel the propaganda produced by the manufacturer, believe me: That last thing pilots are reaching for and the last thing on which safety depends is your POS MR (or AVMED's POS medical certificate) and what they represent.

To add insult to injury, the owner will then have to pay to get the magneto fixed, so that the dodgy plugs can destroy that magneto as well. But who cares. It's "safe" because some LAME has signed an MR, in accordance with the manufacturer's propaganda.

Between that and privatisation of the airports, GA is all but dead. Well done, Australia!

:yuk:

Yes.

I do it already.

I'd be happy to do it on any piston engined aircraft, provided:

- the engine/s is/are at least 500 hours old

- the engines/s was/were run over that period by a pilot who knows how to run piston engines (i.e. not someone full of old wive's tales)

- the engine/s is/are fitted with an all-cylinder engine monitor, and

- the engine/s hasn't/haven't been fiddled with by engineers who don't know what they're doing, or worse, engineers who think the recommendations in maintenance manuals are the product of deep analysis and review and revision in the light of objective data.

I would Yr Right, provided it was in good condition. The odds of it failing in the next 100 hours/year are small. If it does fail, the odds are it won't be catastrophic and the aircraft in question will make it to a suitable landing field. If it is catastrophic, the odds are that the pilot will make a reasonable forced landing and if the pilot blows the landing the odds are he will be relatively uninjured anyway.

Your paranoia of the legal system and litigation is pathetic, you should really change to a "safer" industry anyway. Office work perhaps? CASA even?

Get a life!

The bigger question here is, if yr right or obi wan is actually a LAME, how is it that his daylight hours are spent posting here and not working? Please delete this thread, it's burning my eyes.... ;L

Yes, i do, every time i fly, and work with people that do, and have done for decades.. and not just piston engines..

Before this goes any further, does anybody have a link to any official CASA documents that state where/when this is to happen?

If it does and the new Board and DAS let it happen we can write off Australian private GA and any hopes that anything would change with the new Board.

If the new Board's and DAS's response to the CVD issue is anything to go by, I wouldn't be counting on too many decisions based on objective evidence and objective risk.

Now that is asking a bit much Eyrie!

Just going back to Fujii's original post that started this thread:

We have a rumour started on an airfield, then progressed to a pilots rumour network. If CASA want to bring in 10 year calendar overhauls, perhaps they started to rumour to gauge industry opinion. Looking at this thread and some of the opinions I am thinking they would get away with it.

Dripple dripple and more drippleYou might want to read up a little on the ignition process within the cylinder, and on flame front speed at various mixture strengths, and why the speed varies with mixture. Starting on the lean side, speed of the flame front increases with a richening mixture, reaches a peak at best power, and decreases as the mixture is further enriched. Of course at extreme lean and extreme rich there is no flame front, ergo no speed.Corrected it for you.

I guess we can look forward to more dripple dripple and more dripple.

Obiwan reported as a reincarnation of the banned yr_right.

And an expert on my working hours and holiday arrangements! Is there anything that you don't know, obi? Anything?

I'll say it one more time for the one people that can't don't won't wish to understand: The probabilities of a piston engine you've 'signed out' failing catastrophically are higher on a new engine than one that's on condition. I realise you think you're not going to be taken to court in the former situation, but you'd be rong. :ok:

Obi, please don't confirm my opinion that you are a troll!! :{