Yet another Jab down.....

[motzartmerv]

If the failures were all the exact same part or a couple of parts the solution would be simple.

Nev, the failure modes are very consistent. POST EDITED AS IT DOES NOT ADD VALUE - MOD

 

 

[turboplanner]

I don't think he is, just not remembering the years of thru bolt failures and exhaust valve failures that are there for all to see and the manufacturer, administrators, suppliers, and users to exercise duty of care on.

 

Unfortunately it looks like denial will rule until one or more fatalities occurs, then the house of cards will come tumbling down.

 

On the positive side there will be plenty of people in the chain to pay out.

 

 

[Guest Maj Millard]

I don't think he is, just not remembering the years of thru bolt failures and exhaust valve failures that are there for all to see and the manufacturer, administrators, suppliers, and users to exercise duty of care on.Unfortunately it looks like denial will rule until one or more fatalities occurs, then the house of cards will come tumbling down.

On the positive side there will be plenty of people in the chain to pay out.

Maybe not Turbs, From what I have heard the principal has distanced himself so far financially that it would be almost impossible to track anything......

 

 

[Guest Maj Millard]

I don't think he is, just not remembering the years of thru bolt failures and exhaust valve failures that are there for all to see and the manufacturer, administrators, suppliers, and users to exercise duty of care on.Unfortunately it looks like denial will rule until one or more fatalities occurs, then the house of cards will come tumbling down.

On the positive side there will be plenty of people in the chain to pay out.

My big fear is that one will end up being big news with on-the-ground fatalities....and then everybody including the press saying " well we have known for years that those engines were a piece of Sxxx"...... Going to be pretty hard for anyone to fight those facts in court, regardless of how much money you have.

 

 

[facthunter]

Merv the final failure mode may be the result of other prior factors. Nev

 

 

[Dafydd Llewellyn]

More than happy to Nev, in fact I have been saying this for years now with nobody really listening. I feel the very basis of all the jab problems lies in the CNC machined- from -billet engine case, and I don't feel the problems will ever be solved ( by Camit or anyone) until such time as they change to either a cast or forged alloy case like everybody else uses. The only other engine block I know of which was CNC machined billet wa a drag race engine called a Donovan.It was an exact copy ( with some improvements) to replace the old chrysler 'elephant' cast iron blocks which became hard to get. The Donovan wa only intended to be used for a couple of runs, and I don't even know if they still use them or not.

 

When you CNC mill something out of solid billet you release a lot of internal stresses which wants to throw the finished machine tolerances way out of wack. Unless you intimately measured every dimension on each billet case ( and there would be many to accuratly measure) and rejected those cases that were beyond tolerance, your basically getting what you get, and we've seen the results of that.

 

Additionally a billeted case with a rotating steel hot crankshaft within trying to escape, and very hot steel cylinders attached to it is thermally unstable at best. Your asking for hot spots. The alum wants to move around and expand way more than the steel, hence why they break cylinder and case studs all the time.. Lets remember even the new upgraded ones are still breaking, and there's only one common denominator ...the alum billet cases. Same with the billet heads...not thermally stable enough. Lets get to the valves now, their design is archaic at best. They didn't 't even have oil supply galleries in their valve guides until recently, critical to keeping an exhaust valve cool and eliminating excessive wear on bronze valve guides. Exhaust valve seats set in billet aluminium will not stay there...once again the thermal expansion thing between steel and aluminium ..and for them to have half a chance the valve clearance is absolutly crucial ...too tight with no clearance and its all over red rover very quickly with the valve seat.

 

And if all this is no enough let get to the oil cooling situation on the Jab....ah ....second thoughts, let's not !......I mean what other engine have you ever come across where you have to consult the operators manual to get your proper oil level on the dipstick for your particular engine !....and then have to be happy with 1/8" of oil on the end of the dipstick !...come on now.

 

And Camit ?........looked over their 'new' case at Natfly last,.....same billeted case to me.....oh and what's all these funny oil lines running all over the place?...........oh they are so you can squirt a little oil into the cylinder so the barrels won 't rust when your done flying, replied the friendly sales lady ....give me a break darling, why don't you use high grade carbon or chromium steel like everybody else for your cylinders, and the damn things won't rust in 50 years.............!!!.. So what the magic answer in my opinion ?....go to a cast or forged alloy case like Lycoming, Continental, Pratt & Whitney and Rotax have used for years, and I reckon reliability will improve overnight. Thanks for asking..........

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Point 1:

 

Lycoming and Continental crankcases are made from 355 alloy, which is an aluminium/copper alloy. It starts out in the -T6 heat-treat condition; but it slowly loses strength due to the operating temperature. How do I know? Because I approved a new weld repair process for those crankcases (after a lot of research, done by Rudi's Aero Engines, in conjunction with my son Bob, who was acting as my junior engineer at that time. It took a lot of testing to convince CASA). They usually need weld repair sometime during the second engine life; and by about half way through their third life, they are down to close to dead soft, with weld repairs all over the place, and should really be scrapped. Those cases are sand-cast, NOT forged. They are heat-treated after casting and before machining; thus they have locked-in stresses that may be released during machining, too.

 

The principal problem with cast crankcases is porosity; however a billet case uses wrought material, which eliminates the porosity. There is no wrought equivalent of 355; so Jabiru used what they could get, i.e. 5083. I've not heard of Jabiru crankcases cracking in service, tho no doubt they would if they were run long enough; the principal service problem seems to be indentation of the cylinder flange seat, due to flexure of the "ears" of the cylinder flange, which contributes to(but is not the sole cause of) the loss in through-bolt pre-load. That's not a crankcase design issue; it's a cylinder design issue, which CAMIT has addressed. The Jab. crankcase does not normally get sufficiently hot for thermal instability to be an issue; and it does not start out in a high heat-treat condition.

 

CAMIT have extremely accurate measuring apparatus which runs continuous sample checking, under computer control, so it's not fussy how many dimensions it has to check.

 

Point 2:

 

Jabiru cylinders are machined from 4140 steel, which is a high-grade chrome-molybdenum steel containing 0.4% carbon. In what way does this differ from the material used in Lycoming cylinders? 4140 can be nitrided, as are Lycoming cylinders; however the Lycoming 0-320-E2A engine used in early PA 28-140s had non-nitrided cylinders, being intended for flying school use. I had one; it retained excellent compression right to the end of its overhaul life - but I made a point of doing a couple of circuits in it at least once a week, as recommended by Lycoming. Lycoming cylinders, including the nitrided ones, ARE prone to corrosion unless they are in frequent use; they used to sell chrome-plated cylinders for private-owner aircraft that did not get regular and frequent use; however they've stopped doing that.

 

The crankcase is, unfortunately, NOT the only common denominator in the through-bolt saga.

 

CAMit are focussing on solid-lifters because the routine checking of valve clearances is the best way of monitoring cylinder head and valve issues.

 

 

[turboplanner]

Maybe not Turbs, From what I have heard the principal has distanced himself so far financially that it would be almost impossible to track anything......

Without referring to any current people or issues, distancing yourself from a potential lawsuit you know has a fair chance of coming up can be a crime in itself, and the pursuit is likely to be relentless. This for example could be a case where you've had an accident or have an obligation and transfer all your assets into a trust or your wife's name.

 

 

[winsor68]

No, dont think so.Also remember most of the engines we play with are not certified

With a stroke of a pen they could say they all need LAME annual inspection

Can anyone who was around "back then" elaborate? I'm sure there was more to it. I'm sure there were a lot of old pilots back at the time these engines made an appearance warning of dire consequences to come...

 

 

[Ian Burdon]

Many years ago had a Honda Accord come into my workshop with a serious big end rattle, off with the crossmember and sump to find a 12mm ring spanner inside! My customer left with my bill determined to get it paid for by the mechanic who set the tappets the week before!

So please enlighten us to how a ring spanner can work it's way from the top end to the sump? I know they can become very slippery but that is stretching it a little.

 

 

[bexrbetter]

So please enlighten us to how a ring spanner can work it's way from the top end to the sump? I know they can become very slippery but that is stretching it a little.

http://en.wikipedia.org/wiki/Gravitation

 

 

[Guest Maj Millard]

POST EDITED AS IT DOES NOT ADD VALUE - MOD.........when it became obvious to me (and many other people) that these engines had recurring problems that needed to be fixed, I decided to make some noise in an attempt to force the factory into admitting the problems and fixing them.

 

The factory continues to deny any problems, ( other than with the maintainers ) and the owners certainly weren't making much noise either five years ago.

 

Unfortunatly this tack hasn't produced many positive results, and I don't expect it will anytime soon.....so where to now ......ignore the problems and hope they go away.........?..

 

 

[Jabiru Phil]

What are my motives for being a so- called 'Jab basher'. ????.........when it became obvious to me (and many other people) that these engines had recurring problems that needed to be fixed, I decided to make some noise in an attempt to force the factory into admitting the problems and fixing them.The factory continues to deny any problems, ( other than with the maintainers ) and the owners certainly weren't making much noise either five years ago.

Unfortunatly this tack hasn't produced many positive results, and I don't expect it will anytime soon.....so where to now ......ignore the problems and hope they go away.........?..

POST DOES NOT ADD VALUE - MOD

 

 

[alf jessup]

Fix the problems and no one would have a reason to comment, but until the factory admits they are producing quite a lot of inferior engines and components and actually decide to help the poor people that pay good money for them the comments will continue on a regular basis as these things continue to self destruct.

 

All I can say is thank goodness Camit are at least trying to address the problem as the factory doesn't seem to think they have a problem after you have paid them that is.

 

They are popular alright just look in the classifieds

 

 

[turboplanner]

What are my motives for being a so- called 'Jab basher'. ????.........when it became obvious to me (and many other people) that these engines had recurring problems that needed to be fixed, I decided to make some noise in an attempt to force the factory into admitting the problems and fixing them.The factory continues to deny any problems, ( other than with the maintainers ) and the owners certainly weren't making much noise either five years ago.

Unfortunatly this tack hasn't produced many positive results, and I don't expect it will anytime soon.....so where to now ......ignore the problems and hope they go away.........?..

Keep telling it as it is the way you are Major, because you are espousing safety and trying to warn people of risk.

 

If a fatal or string of fatals occurs, the people who coined the term "Jab bashers" to try and shut down any debate will come under scrutiny because they are legally responsible for their advice, and some of it has been downright misleading.

 

 

[Captain]

I have asked before on these Forums and I ask again.

 

 

 

If the 2200 and 3300 engines are exhibiting the problems that you are discussing here, why is this not showing up in the VH registered versions to an extent that CASA would be forced to take some action?

 

 

 

When the printed versions of the Crash Comic were coming in the mail I could never find much about 2200 & 3300 engine issues in the appropriate section of the Mag.

 

 

 

Regards Geoff

 

 

[gandalph]

Dafydd,

 

You recent post bringing evidence based factual information into a highly opiniated thread is most welcome and refreshing. However I suspect you are trying to teach the frogs chorus to sing a different song. A challenging task, but worth the effort?

 

 

[Guest Maj Millard]

I have asked before on these Forums and I ask again. 

 

If the 2200 and 3300 engines are exhibiting the problems that you are discussing here, why is this not showing up in the VH registered versions to an extent that CASA would be forced to take some action?

 

 

 

When the printed versions of the Crash Comic were coming in the mail I could never find much about 2200 & 3300 engine issues in the appropriate section of the Mag.

 

 

 

Regards Geoff

They were starting to get a mention now and then Captain and pretty much in every edition.......what percentage of the fleet carry VH rego anyway ?...

 

 

[dutchroll]

You recent post bringing evidence based factual information into a highly opiniated thread is most welcome and refreshing. However I suspect you are trying to teach the frogs chorus to sing a different song. A challenging task, but worth the effort?

Geezus.

Yeah, OK, we can cut and paste whole chapters of University metallurgy textbooks here but does it get us any closer to solving the question of "what do we do about the apparent failure rate of Jab engines"? No, I would argue that it does not.

 

Yes there are opinions voiced here (oddly enough you get that on internet forums), and occasionally even facts. However it would seem to me that neither have so far made any impression on what we might term "the Jabiru issue".

 

Here we are with Jabs still gliding into paddocks with varying success rates and the action we see is........

 

 

 

[Captain]

They were starting to get a mention now and then Captain and pretty much in every edition.......what percentage of the fleet carry VH rego anyway ?...

G'day Ross,

 

 

 

I accept that the VH fleet is much smaller than the RAA fleet, but if the engine issues are such, I would have expected enough turning up there to trigger CASA action.

 

 

 

But perhaps they are treating it like the R44 fuel tank issue and waiting for a few high profile fatalities before really doing anything.

 

 

 

If I were on the RAA Board like you and Andy, I would be wanting myself and the organisation to be (and be seen to be) pro-active to address the issues which are now so widely discussed if they can be adequately technically and commercially defined and actioned.

 

 

 

Regards Geoff

 

 

[Guest Maj Millard]

Geezus.Yeah, OK, we can cut and paste whole chapters of University metallurgy textbooks here but does it get us any closer to solving the question of "what do we do about the apparent failure rate of Jab engines"? No, I would argue that it does not.

 

Yes there are opinions voiced here (oddly enough you get that on internet forums), and occasionally even facts. However it would seem to me that neither have so far made any impression on what we might term "the Jabiru issue".

 

Here we are with Jabs still gliding into paddocks with varying success rates and the action we see is........

 

Dutchroll, you may want to direct that question directly to the source...the Jab factory ?....

 

 

[Dafydd Llewellyn]

I've no issue with people reporting problems - that's certainly what a forum like this is for.

 

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The best way to help existing Jab owners is to provide an engine rebuilding service that deals with such issues as Ian Bent has identified; that's what Maj evidently saw (and did not comprehend). The advantage of doing it that way is that there would be no legal hoops to jump through about putting it into an existing airframe, because it's legally a Jab engine with approved modifications.

 

Of course it still looks like a Jab engine; it still IS legally a jab engine, however the product liability would be divided between CAMit and Jabiru in some way according to the modifications, and that may well be a bone of contention between CAMit and Jabiru.

 

If that approach is blocked by the product liability issue, then the alternative will be for CAMit to go the whole nine yards, and certificate an engine containing the lessons from the Jab engine, plus a few more fundamental changes. That would probably produce a better engine still, but it then involves an STC to put it into certificated airframes; and it would still need Jabiru's "No objection" response to put it into LSA airframes.

 

So, where to from here? That depends on some resolution of the product liability issue; and some other commercial aspects on which I cannot comment. But sniping at Ian Bent's attempts to come up with an overhaul program for existing jab engines to incorporates improvements - many of them too subtle to be obvious - for what would remain fundamentally a Jabiru engine - on the basis of "that's not the way Grandad did it" (or any other similar bar-room wisdom), is not helpful.

 

 

[motzartmerv]

This is what annoys me.. Why should it be up to Ian, or camit, or the owner to sort the problem?

 

 

[Admin]

There are 2 main engine brands that we use, Rotax and Jabiru. Could we get, and how could we get, statistics on all the failures of any kind both in the air and on the ground, and compare them to see exactly where we stand and if there is an alarming difference then possibly something could be done in the interests of our safety...but you need facts and only facts

 

 

[turboplanner]

There are 2 main engine brands that we use, Rotax and Jabiru. Could we get, and how could we get, statistics on all the failures of any kind both in the air and on the ground, and compare them to see exactly where we stand and if there is an alarming difference then possibly something could be done in the interests of our safety...but you need facts and only facts

RAA already publishes monthly in the magazine all the reported engine failures, but the facts are less than satisfactory.

 

What is not available are the engine failures/forced landings which are not reported, so the official figures are being under-reported.

 

If you have a way to force those people to be honest and report their incidents you will have a complete database.

 

If a proforma report form was produced, and we know the signs to look for after all these years then you will have more useable information.

 

However, whether that would be acted on by the manufacturer or the administrators remains to be seen.

 

 

[jetjr]

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spend time looking at the task of allowing those who engineer upgrades be allowed to implement them. Start investing time sorting out regulatory ways out for all those stranded and broke Jabiru owners mentioned. Running down the product and belting on about Jabiru fixing it, isnt working and is unlikely to. Just brings down Jabiru owners not the company.

 

Just say we follow your advice, totally redesign engine (to you specs of course) and it without doubt proves to be reliable for 5000 hrs TBO without even oil changes. How is this going to help 25 reg Jabiru owners?

 

Jabiru either cant or wont get involved in re-engineering their engines. Maybe from experience in things like Hydraulic lifters. Where what was a widely used and promoted technique has turned out to be a major contributor to a string of problems over years. No doubt cost them dearly and IMO still does. Continually saying that they should fix it is such a waste of time.

 

Now with Ian working on his own thing I doubt he is going to hand his IP to Jabiru. Leaves them with problems and not much solution.

 

People with LSA purchased them with the restrictions in place to get a factory built aircraft. It was always going to be the case that were there issues builder wouldn't recognize, see a commercial conflict etc etc. that they were stuck with what they bought. Even common sense upgrades would maybe not be permitted.

 

Aftermarket upgrades is a logical and solid answer but at this stage they can only sell them to small number of 19 regd aircraft so who would spend the time and money? And it will take a lot of both.

 

How about get going getting paperwork together on 912 transplants going, build a kit.