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Jabiru engine failures

Old 13th Nov 2014, 21:38
  #21 (permalink)  
 
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Sounds like a metallurgical level issue.
If I was running Jab I would be offering good deals for engine swaps for engines that reach TBO. Would be smothering a few high use engines with data logging. The engineer in me sees these failed engines as very valuable resources...why the hell isn't the manufacturer doing deals to get the cores back into the factory and under the microscope.
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Old 13th Nov 2014, 22:23
  #22 (permalink)  
 
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Ozbusdriver:

Sounds like a metallurgical level issue.
If I was running Jab I would be offering good deals for engine swaps for engines that reach TBO. Would be smothering a few high use engines with data logging. The engineer in me sees these failed engines as very valuable resources...why the hell isn't the manufacturer doing deals to get the cores back into the factory and under the microscope.
Without a competent statistical analysis of the failure types and rates, CASA and the RAA are wasting their time.

However I doubt that a technical analysis of failure modes is going to be much help to the Jabiru engine company for the following reasons:

1. Statistical analysis may not prove conclusive given that ATSB does not investigate incidents and the RAA seems to be wanting as well. There also needs to be a distinction drawn between what I will call "professionally maintained" engines and amateur maintenance of kit built aircraft. This needs to be done so that conclusions can be drawn about different fleets because failure may be maintenance sensitive (or not). Then there is the question of mod status.

2. Now that Lawyers are involved (if its CASA, the lawyers are calling the shots) Jabiru faces an almost insuperable barrier to a return to normal operations because it is going to be asked to present "negative Evidence" ie: Evidence that demonstrates that the engine is safe by industry standards. That involves identification of failure mode, corrective action then considerable testing to prove that the problem is fixed at the 99.999 percent confidence level.

However even this won't be enough. Now that CASA has got itself involved it has foregone the defence of "plausible deniability" if there is a multiple fatality. What will now be required of Jabiru is an impossibly high standard of evidence such as to be sufficient for a court to completely exonerate CASA from all liability whatsoever in the event of a future accident. I do not believe CASAs lawyers will settle for anything less and I think they will take their time before deciding.

I short-handed this message in an earlier post but my feeling is that I doubt the Jabiru cash flow can sustain such a marathon nor will engine sales continue while it is in this state.

If its any consolation at least CASA didn't wait till Friday at 4.30pm.

P.S. To be fair to CASA, I believe I've heard that Jabiru management has been somewhat less than proactive in the product improvement area, but I stand to be corrected.
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Old 13th Nov 2014, 23:08
  #23 (permalink)  
 
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Oh well, I am sure there is a Chinese company willing to buy up the design.

Cheap!

Without "Foster and Promote" in their charter there is no incentive for CAsA to work "with" anyone except the lawyers who's only brief is liability "risk management", forget about safety.

Industry has safety risk management programs.

CAsA has a Liability risk management programs.

Its easy to be critical of the company, but CAsA at times, especially if your confronted by the wrong person, can be impossible to deal with.

Its not just CAsA unfortunately the liability risk management model is infused right across the bureaucracy, which is partly why we don't make anything here anymore.
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Old 13th Nov 2014, 23:10
  #24 (permalink)  
 
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Jaba, with your experience, do you think this can be fixed quickly?

Seems like the major problems are still the through bolts (?rolled vs cut threads), valve guides (?cam/rocker design) and crankcase fretting. Of course, as Sunfish points out, we don't have any good stats and there is the maintenance confounder, but do we have the answer and is it as simple as an SB (I suspect not, but we can live in hope).

Pity Jabiru has chosen to head to Canberra with their lawyers instead of engineers. They have received poor PR advice - the legal approach and a letter writing campaign will not wash with CASA (or more importantly the public, ever fearful of those nasty ultralights crashing through the roof of their kindergarten), it just looks like a defensive cover up. Over many years, and across many industries, we have learnt that the only way to deal with these crises is to fess up and be cooperative in working to find a solution. The lawyers will only stuff it up and hasten the demise of Jabiru - we need experts here, not guns for hire.

There are times I hate CASA with a passion, but I have to agree with Kharon that it seems they had little option - Jabiru has failed to deal with the known issues and RAAus has failed in its responsibilities (I think after all the fiascos, CASA will give them trikes not above 300ft and roll everything else back into CASA/RPL and who could blame them).
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Old 13th Nov 2014, 23:11
  #25 (permalink)  
 
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You are not wrong JetJr.

LSA is a can of worms for aircraft manufacturers and owners.

If any one of these European aircraft manufacturers goes belly-up, then Aussie private operators and flying schools have 30 days before their birds are grounded and then transferred to experimental registration, thus rendering their flying school and income potential zero, or at least until they can get another aircraft on-line.

If Jabiru went under, the majority of schools with Jabiru aircraft are gone in 30 days.

I'm thinking though and I know it's different..... Cessna stopped making aircraft and General Aviation didn't cease across the world.
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Old 13th Nov 2014, 23:14
  #26 (permalink)  
 
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Originally Posted by Sunfish View Post
If its any consolation at least CASA didn't wait till Friday at 4.30pm.
Given responses due Thursday 20th, expect the final instrument to be faxed 4:30pm on Friday 21st ....
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Old 13th Nov 2014, 23:23
  #27 (permalink)  
 
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Sunnie, me think there are too few...as many as there are worldwide...for a stat method to pick up faults. The best way is to get your hands dirty and start reading the witness marks and recording individual events to make the picture from that end rather than failure o'er 100000hrs in use. The company is small run so it should never have been difficult to change a design, process or material.
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Old 13th Nov 2014, 23:53
  #28 (permalink)  
 
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Sad turn of events, for Jab and the RAA. Makes us all look like a pack if diks really. I hope Jab come to the party and initiate real change, and I hope CASA can relax their grip around the throats of Jab and allow it to happen. Knowing the company tho, I dont hold much hope for compromise.
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Old 13th Nov 2014, 23:58
  #29 (permalink)  
 
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Both parties meet in a few minutes at 11am.

Let us hope for an outcome that keeps everyone happy.

RA-Aus is meeting with CASA today also.
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Old 14th Nov 2014, 00:11
  #30 (permalink)  
 
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Having been on the pointy end of a Jabiru engine failure, having completed the Jabiru Maintenance Course and having run a flying school which used a Jabiru I have a few insights into the issue.
Firstly you need to differentiate between the 2200 & the 3300, each engine has it's own but different problems. The 2200 is mainly through bolts and the 3300 is mainly pistons/rings and especially exhaust valves. Secondly you have to differentiate geographically if the engines are run on AVGAS. The West, including SA (and maybe NT) are supplied with the Green, high lead, fuel while the East is generally supplied with the low lead blue. This has an impact on lead build-up in the engine.
Thirdly you need to differentiate on equipment level, i.e. do they have the single CHT sensor on No. 6 or are they fitted with the Dynon and have EGT/CHT on all cylinders.
With regards to maintenance it is no so much wether it was a "Professional" or an "Amateur" but more a case of how often. For example, a J230 (3300 engine, running on AVGAS Green with single CHT) has a top end clean (deposits removed, valves lapped etc) every 200 hours and hasn't had a failure in over 600 hours. This is not part of the Jabiru recommended maintenance schedule. The point being some people will go above and beyond the "required/scheduled" maintenance or strip the engine/top end at the slightest possibility of a hint of a problem. When this engine goes to TBO they say they never had a problem or failure, which is true. The other person who just does the recommended scheduled maintenance per the book, to Jabiru standards, plus any AD's etc and the engine fails at 300+ hours whilst flying therefor generating a statistic.
Most of my experience is with the 3300, and the engine will go to TBO IF you clean the top end every 200 hours, modify the baffling to get an even spread of CHT's (illegal if 24 reg) and fit fuel injection (again illegal) or possibly re-jet to run really rich (25-30 L/hour at 75% power).
As for the 2200 engines I'm not sure, but one here is only used for private flying and generally flies at 2900-3000 rpm, doesn't do circuits, is maintained above and beyond recommended levels and is running nice at 400+ hours so far.
In my case the engine was maintained to the required level as per the Jabiru Maintenance Manual, only had the single CHT and run on green AVGAS. After doing the mandatory morning pull throughs with no issues, at 282 hours about 40 minutes into a 2 hour flight the engine ran rough for 10 seconds then stopped solid, found a paddock and got down with only a few bruises. Aircraft carted off to Jabiru by the insurance company, and when we tried to find out what went wrong with the engine they wouldn't tell us! When we asked for the engine to be sent back they said they can't because it had been binned! We got a new engine (we got pro-rata for the hours remaining) and our aircraft fixed but to this day have no concrete evidence of what happened.
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Old 14th Nov 2014, 00:38
  #31 (permalink)  
 
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And there is the problem Dexta. My school has had similar stories.
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Old 14th Nov 2014, 01:05
  #32 (permalink)  
 
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You might want to look here as well.

https://www.facebook.com/JabiruAircraft?fref=ts

The problem also appears in the Private Flying forum.
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Old 14th Nov 2014, 01:11
  #33 (permalink)  
 
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Petition

Sign the petition at CHANGE.ORG if you can.
Results will be forwarded to Warren Truss MP.

There appears to be overwhelming support from the aviation community that CASA is being too heavy handed here.
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Old 14th Nov 2014, 03:04
  #34 (permalink)  
 
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After 4 yrs of persistence, in 2013 we finally gave up on our J160 which had done 850TT for 2 engines and loads of grief in between. We were unable to rely on the aircraft, and lost sleep over student flying. We were most unhappy with the manufacturers attitude.

We sold it for a very acceptable price in late 2013. We've ordered a Brumby and take delivery soon.

So, todays crunch was a long time coming!
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Old 14th Nov 2014, 03:05
  #35 (permalink)  
 
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This is where a lot of the problems could be fixed.
modify the baffling to get an even spread of CHT's (illegal if 24 reg) and fit fuel injection (again illegal) or possibly re-jet to run really rich (25-30 L/hour at 75% power).
The cooling air distribution is something very few understand at all.

Fuel DOES NOT COOL, it delays the Theta PP and lowers the ICP. Hence a lower CHT. This is the wrong way to cool an engine.

I reckon cooling issues and distortion of heads as a result are 45% of the problems, and the result from running far too rich the other 45%. 10% could be any number of things. Just shooting from the hip.
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Old 14th Nov 2014, 03:45
  #36 (permalink)  
 
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Fuel DOES NOT COOL, it delays the Theta PP and lowers the ICP. Hence a lower CHT. This is the wrong way to cool an engine.
Agree with Jabba on this one 100%.

Jabiru engines in their native installations run hot.

Many an owner / maintainer simply pumps in additional fuel in an attempt to "cool" the engine. It will take a lot of fuel to cool a cylinder; in fact you may cool the head but not the cylinder. In fact by pumping in extra fuel you run the risk of it going through in gobs and causing issues; this is an issue in aicraft that are un-cowled.

AIRFLOW is the only way to cool these AIR COOLED engines. Unless you are running a stupidly lean mixture and cooking your heads, adding fuel will NOT help.

A 120hp Jab engine should in theory be able to run at around 19 lph IF cooled properly with AIR.

I can definitively demonstrate to anyone that wants to watch, that fuel will NOT cool a Jabiru engine or at least not to any significant amount worth mentioning.

If owners weren't skimping on engine monitoring and took the time to listen to the factory and fit 8 or 12 senders for CHT & EGT and take notice of what they are telling them, then a significant proportion of these issues would have been nipped in the bud a long time ago.

There are owners at my airport too stingy to fit the required instrumentation and thus are hitting regular problems like valves burning out. At least with monitoring, mixtures could be adjusted accordingly to rectify the problem. Some would say that an owner shouldn't have to do this, however if you have the ability to fit such devices and rectify the problems, you would be crazy not to.
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Old 14th Nov 2014, 03:57
  #37 (permalink)  
 
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from talking to other LAMEs who have had a good record with Jabirus, it could possibly be the construction technique that is the root cause, and also, not having any idea whats going on with regards to mixtures and combustion events.

the crank cased are bolted together, no gaskets, just metal to metal and a thin layer of silicon between the mating surfaces.. something i have been told is a big no no in engine construction... leads to fretting etc...

Unless you are running a stupidly lean mixture and cooking your heads
Don't you mean, Not lean Enough?
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Old 14th Nov 2014, 04:09
  #38 (permalink)  
 
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Yes Mr APS attendee. You know what I mean, stupidly lean.

Out of balance props certainly contribute to fretting.

There is now fretting across the entire Jabiru fleet, but fretting of a different kind.
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Old 14th Nov 2014, 04:32
  #39 (permalink)  
 
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Yep, a simple Bendix or Airflow performance style injection system. I reckon it could have two settings, and being mass airflow designs they could have a F/A ratio set for take off and climb, and one for cruise and descent.

Piece of cake with the right motivation. That and proper cooling, or even the Rotec water cooled heads. which would mitigate that issue. Although I prefer a proper air cooled design, it works well for Rotax and seems to work for others.

Along with some material changes on valve guides and we would solve most issues easily. I am not sure the hydraulic lifters are the go, and with the old solid lifter engines (less problems) and better F/A ratio's and cooling, most of the head creep would go away.

I see a solution…..if only we can get them to have me around the table. If anyone is reading this that matters.
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Old 14th Nov 2014, 04:56
  #40 (permalink)  
 
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I wonder if there's more to this than meets the eye. Jabiru don't actually manufacture these engines and I've heard that the guy who does has been concerned about the design being shipped elsewhere.

I have no concrete evidence - this is a rumor network after all - but there could be some inter-company politics behind this that has gone wrong, or right or something else entirely.

I feel for the guys making the Jab engine because they do know how to make them and they have a much better reputation overseas than they do here (sound familiar...?) It's also an industry with high costs and slim margins where redesign and re - certification is often prohibitive, let alone new designs.

It's something of a shame that CASA didn't knock on the door and have a quiet word to fix this up without destroying company and brand reputations, but perhaps they already have tried this and failed so they turned to the nuclear option. I don't know.

Whatever happens, it's always easier to destroy than it is to build up and plenty of Aussies seem to like to see destruction...
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