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Jabiru engine failures

Old 16th Dec 2014, 01:28
  #281 (permalink)  
 
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I never knew rotax printed different maintenance schedules for engines fitted to Vh regoed aircraft... i cant find the GA maintenance schedule anywhere thats different to my schedule...
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Old 16th Dec 2014, 07:04
  #282 (permalink)  
 
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Don't think they do, UL. I suspect my certified 912 S2 schedule looks just like the UL versions. My point was mainly about using the stats to see if conventional wisdom (LAME = better maintenance) was supported.

I take little on trust these days, LS, having seen seen pretty agricultural maintenance practices in all regimes. But for all of the frustrations, I still prefer to have my bug smasher annuals done by a LAME, despite other potential options for the particular aircraft. I agree, though, that finding the right LAME is not trivial, especially when VLA/LSA engines are involved.
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Old 19th Dec 2014, 00:27
  #283 (permalink)  
 
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A little birdie tweeted to me that we might be headed for a 4:30pm Chrismas Eve time-bomb on this one with Christmas eve for most of the corporate world being today
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Old 19th Dec 2014, 02:59
  #284 (permalink)  
 
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A CASA Christmas gift to Jabiru would be positive proof that the entrenched culture of CASA is going to be very difficult to change.
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Old 20th Dec 2014, 07:09
  #285 (permalink)  
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Here it is. Civil Aviation Safety Authority - Precautions for Jabiru powered aircraft
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Old 20th Dec 2014, 07:29
  #286 (permalink)  
 
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Here's the actual legislative instrument, number CASA 292/14. Or at least it will be when it becomes legislation.

One of the requirements is a signed statement, substantially like the one below, before you may carry a passenger in your now-all-but-worthless plastic parrot.

So long, Jabiru.

​​‘I, [insert name] ​, PROPOSE TO TAKE A FLIGHT IN THE AIRCRAFT IDENTIFIED AS [insert registration information] (THE AIRCRAFT). I AM AWARE THAT THE CIVIL AVIATION SAFETY AUTHORITY (CASA) HAS DATA INDICATING THAT THE TYPE OF ENGINE USED IN THE AIRCRAFT HAS SUFFERED A HIGH NUMBER OF FAILURES AND RELIABILITY PROBLEMS.

​​‘I ACKNOWLEDGE THAT CASA HAS IMPOSED LIMITATIONS ON THE AIRCRAFT TO PROTECT PERSONS ON THE GROUND NOT ASSOCIATED WITH THE OPERATON OF THE AIRCRAFT, UNINFORMED PASSENGERS AND TRAINEE PILOTS. THOSE LIMITATIONS ALSO HELP PASSENGERS AND TRAINEE PILOTS TO MAKE AN INFORMED DECISION ABOUT WHETHER TO ACCEPT THE RISK OF FLIGHTS IN THE AIRCRAFT.

​​‘I NOTE CASA’S ADVICE THAT, ALTHOUGH MOST JABIRU ENGINES OPERATE NORMALLY, THERE IS AN ABNORMAL RISK THE ENGINE IN THE AIRCRAFT WILL MALFUNCTION.

​​‘I ACCEPT THE RISK OF BEING INJURED OR KILLED IN THE EVENT OF AN ENGINE MALFUNCTION DURING FLIGHT, NOTING THAT:
‘(A)​THE AIRCRAFT MUST BE FLOWN AWAY FROM PEOPLE ON THE GROUND (AND BUILDINGS), EVEN IF THAT MEANS AN EMERGENCY LANDING AT A LOCATION THAT IS LESS SAFE FOR THAT PURPOSE; AND
‘(B)​THE SAFETY OF AN EMERGENCY LANDING CANNOT BE GUARANTEED EVEN IF THERE IS A SUITABLE LANDING LOCATION.

​​‘I NOTE CASA’S ADVICE THAT I SHOULD NOT FLY IN THE AIRCRAFT IF I AM NOT PREPARED TO ACCEPT THE HEIGHTENED RISK INVOLVED.

​​‘I ACCEPT THE RISK NOTING THAT THE ENGINE MANUFACTURER IS WORKING TO IDENTIFY AND FIX THE ENGINE ISSUES AS SOON AS POSSIBLE.

​​‘I AM AWARE THAT CASA REQUIRES MY SIGNATURE ON THIS STATEMENT BEFORE THE FLIGHT MAY COMMENCE.
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Old 20th Dec 2014, 07:41
  #287 (permalink)  
 
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Interesting. So Jabiru engined operators in Bankstown and Moorabbin for example have until January 31st 2015 to go elsewhere.

Someone told me that this would happen well over a year ago. Interesting that it started out far more harsh than this and ended up back at what I was told back then.
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Old 20th Dec 2014, 07:42
  #288 (permalink)  
 
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Interesting, and as a method for "shifting liability", worthless.
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Old 20th Dec 2014, 08:34
  #289 (permalink)  
 
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I just love this bit of arse covering:

These figures follow reported engine-related events in 2012 and 2013, although CAsA has only recently become aware of the full scope of the issues that appear to have occurred during that period through provision of data from a number of additional sources.
Shirley a competent regulator should be well apprised of safety issues? Or is that too much to expect, or maybe the regulator is incompetent?

The Explanatory Statement makes many assertions without any data to back them up - surely they could give us some statistics to support their draconian regulation.

At least we don't have to deal with the Friday afternoon fax any more, it's now the Saturday afternoon press release. Well done PG!
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Old 20th Dec 2014, 09:30
  #290 (permalink)  
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This is just CASA's way of keeping pressure on Jabiru to come up with a solution which will satisfy CASA enough to drop the restrictions.

So, now the lawyers will get involved or Jabiru will go broke or both.
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Old 20th Dec 2014, 10:32
  #291 (permalink)  
 
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Watered Down

These restrictions are far less draconian than originally planned and maintain the ethos of light sport aviation, eg I fly at less cost but I accept the risk.

Flying above populous areas only if you can glide clear, Day VFR, etc are all standard existing rules in RAA.

Informing a prospective student gives them a cue to make an assessment of the risks, and is really just a paper shuffling exercise. Forced landing practice before and after solo is basic stuff that every student should be drilled with. It seems the only group who's aircraft will lose privileges are those with letters on the side? Surely this is a lesser number of the Jabiru fleet. If so why did CASA accept GA certification of the engines in the first place?

Hate to say it but I think CASA got this one just about right, given the known issues with the engine and Jabiru's recalcitrance in fixing them. The real question is how will the issues be resolved. CASA says it may review and relax the restrictions early in the new year but I fail to see how any statistical case for this can be made in such a short time, this is probably just a placatory move to delay litigation by owners.

I wonder if CASA might have been muzzled?
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Old 20th Dec 2014, 17:50
  #292 (permalink)  
 
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Death sentence for Jabiru. No future sales are possible. CASA says jabirus are death traps.


But the question, CASA, is death trap compared to what?

There can be no relaxation in future because that would require "negative evidence" and the only amount that could satisfy the lawyers is a full FAA certification which is impossibly expensive.

Jabiru will not reopen in the new year. CASA continues its tradition of killing an aviation business every Christmas.

Furthermore CASA has just set a precedent. It can libel any business or thing it likes. How about Vans aircraft CASA? A lot of them have fatal crashes.

Last edited by Sunfish; 20th Dec 2014 at 18:27.
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Old 20th Dec 2014, 20:31
  #293 (permalink)  
 
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Hate to say it but I think CASA got this one just about right
Sage words Oracle but I ask; got it right on what evidence? Got it right for which engine ... all of them including the latest version it seems? Sorry Oracle, I disagree, casa as usual got it wrong and overreacted. A disgusting restriction on an Australian manufacturer who has succeeded despite all odds.

Given the evolution of this engine, the latest version should be exempt save for perhaps a reduction in TBO.
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Old 20th Dec 2014, 20:40
  #294 (permalink)  
 
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A little melodramatic there Sunfish as usual.

They will re-open as per normal on Jabuary 5th.

Why scrap arguably some of the worlds best airframes when they could simply be re-engined if it came to that? They don't owe anyone any money and are a strong company. One of the benefits of an LSA and kit manufacturer is self-certification so they "simply" sign-off the new install or kit builders simply fit an engine of their choice - No significant CASA involvement required

It's just an engine, not the end of the world.
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Old 20th Dec 2014, 22:12
  #295 (permalink)  
 
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Aussie Bob,

I think CASA got it about right. What do you think they should do? They can't let things go on 'the same'.

Your thoughts on managing the known risks with these engines?
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Old 20th Dec 2014, 23:08
  #296 (permalink)  
 
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..........

Last edited by Radix; 18th Mar 2016 at 02:17.
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Old 20th Dec 2014, 23:41
  #297 (permalink)  
 
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Rod Stiff doesn't listen

Rod Stiff has been warned many times by highly qualified engineers of the problems with the engine that are easily identified by known mathematical theory such resonance issues within the engine. This stuff is not cutting edge and is common knowledge amongst the fraternity.

Reliability is achieved in engineering by research and development, generally but not always the more money you spend the better the result. The engine was developed on a shoestring budget and it's time to face the fact that a more intensive, expensive solution is required. There is no doubt the engine has evolved and improved but glaring issues still exist.

CASA had to do something and the result is CASA protecting the integrity of the VH rego. Not much has changed if you fly with numbers, but if you want to fly VH, you pay your extra money for the certification regime and the perceived safety that it delivers. CASA has effectively put VH registered Jabiru powered aircraft in the same operating regime as RAA.

In fact it's refreshing that CASA have respected the right of avaitors to kill themselves in a manner in which they see fit, just as long as they don't harm others in the process. I have NO love for CASA but in this case I think they got it about right.
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Old 20th Dec 2014, 23:49
  #298 (permalink)  
 
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Oracle, I guess then the best thing would be to sell the rights to china,or the Indians. Let them make them and buy the engines from them.
Not much point banging your head against a brick wall in Australia, look what happened to the Airvan, better to walk away with a few bucks than be in constant conflict with a bureaucracy determined to shut you down.
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Old 21st Dec 2014, 00:16
  #299 (permalink)  
 
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Rod Stiff has been warned many times by highly qualified engineers of the problems with the engine that are easily identified by known mathematical theory such resonance issues within the engine.
Oracle 1

Could you shed some more light on the resonance issues. I havn't had any hands on experience with Jabiru engines but I have 'heard' that resonance can be a problem if any prop other than a wooden one is used and that Jabiru only approves wooden props.

I 'heard' that the flexible nature of a wooden prop acts as a quill shaft or as a torsional balance . If you use a fairly inflexible composite or worse a metal prop things will break inside the engine. I'm sure you would have knowledge pertaining to this and will be able to clarify the situation.
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Old 21st Dec 2014, 09:05
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Squawk7700

Why scrap arguably some of the worlds best airframes when they could simply be re-engined if it came to that?
Absolutely spot on. My choice for a personal transport machine is a J200 fitted with a Rotax 914 Turbo. Its been done by a guy in Tumut with excellent results.

One of the benefits of an LSA and kit manufacturer is self-certification so they "simply" sign-off the new install or kit builders simply fit an engine of their choice
A double edged sword. It can reduce costs and red tape in implementing engineering fixes and updates but can be manipulated by manufacturers for commercial reasons, such as excluding other parts manufacturers or to introduce changes that have not been tested comprehensively, something Jabiru is well known for.

Aussie Bob

Sorry Oracle, I disagree, casa as usual got it wrong and overreacted. A disgusting restriction on an Australian manufacturer who has succeeded despite all odds.
I respect your opinion on this and I myself made phone calls in support to Truss's office, leaving the electoral officer in no doubt as to the ramifications of a CASA execution. I think in the prelude CASA's behaviour and release of documents was atrocious. My personal opinion is that CASA has been muzzled on this one, once the politicians realized the shit fight that would occur. Either that or CASA are trying to make us grateful that we only got two of the best not six. Threatening the owners (who can afford to have up to ninety grand lying around) of what is essentially a non commercially viable toy could quickly result in a messy class action and may still do. Flying schools conducting commercial training out of Bankstown, Moorabbin and Archerfield fall squarely within CASA's perceived turf, are not able to threaten CASA, and will be crushed. I support Jabiru and they have achieved miracles but one can never rest on your laurels. It is Rod Stiff's business and he can run it how he pleases, but eventually rising outside pressure must be acknowledged.


Thorn Bird

Oracle, I guess then the best thing would be to sell the rights to china,or the Indians. Let them make them and buy the engines from them.
Rest assured Stiff has already flirted with Chinese manufacturing. It was tried with the Drifter as well until cables started snapping while taxiing. Chinese manufacturing doesn't have the quality control quite yet but they have bought companies such as Mooney and Continental, be assured they will be reverse engineering until they can eliminate the West. Buy or steal, 250 years of engineering know how has been handed over on a platter by greedy plutocrats intent on making a cheap buck on the slave labour margin, leaving Western youth unproductive and aimless.

Finally and of the greatest interest,

Rutan Around,

I 'heard' that the flexible nature of a wooden prop acts as a quill shaft or as a torsional balance . If you use a fairly inflexible composite or worse a metal prop things will break inside the engine. I'm sure you would have knowledge pertaining to this and will be able to clarify the situation.
I thank you for this compliment but unfortunately, thanks to a misspent youth and mathematical ineptitude, I am but a glorified mechanic. However, unlike many of my fellows, I am obsessed with flying all things small and I have made concerted efforts to both understand and control the theoretical risks from a practical viewpoint. The conversation I had with one CAR35 engineer regarding the Jab engine and pertaining harmonics was many moons ago and I have long since lost interest in the engine. From memory the problem wasn't prop related, but don't quote me on that. If you wish to delve further I have PM'ed you the contact details of said gentleman, who is well known for his interest and charity in facilitating flying for the masses. I highly recommend his three DVD set on aircraft design which is presented in layman's terms, is highly informative and worth every penny.


Regarding wooden props,

Wooden props are well known for fatigue resistance and damping harmonic resonance due to the flexible nature of the material. (Just like a tree blowing in the wind, still many things we cant beat nature at). They have weaknesses as well such as structural integrity and swelling with humidity but composite sheathing and metal leading edges have begun to address some of the problems. Wood has become a material of choice in some highly advanced composite propellers such as MT, who's expertise is unquestioned. Wood is also lighter and has less momentum. Metal props have a tendency to propagate certain frequencies, when certain frequencies coincide amplification occurs and the energy has to be absorbed somewhere in the aircraft. Jabirus reasons for the choice of wooden prop include the properties mentioned but they also have commercial imperatives, including cost of manufacturing and testing. The wooden prop is also desirable (given the amount of low time pilots) in the event of a prop strike as the ends just shear off. Jabiru was testing a two blade composite prop with a swept foil. They had great success in the performance area but they found that the carbon fibre version was simply too stiff and they reverted to fibreglass. I don't know what came of this. Others have designed and fitted composite props to Jabiru engines, no one has died yet, but it is unknown whether this is by accident or design. I stress that no definitive answer can be reached on harmonics and the nodes at which it is present unless you hook up vibration sensors, collect data in multiple operating regimes, and have someone available who is able to interpret the results. I would like to know if Jabiru has conducted this exercise.


In conclusion harmonics is a little understood (by the unwashed masses) and highly dangerous phenomena which can destroy integral structures rapidly and with no warning. One example that comes to mind that completely dodged the brightest minds was the whirl mode on the Lockheed Electra, an aircraft that went on to give good service in specific roles, for a simplified explanation see here,

Lockheed L-188 Electra - Wikipedia, the free encyclopedia

Harmonics needs to be examined with the whole aircraft in mind. Early research into harmonics in GA aircraft caused some big surprises. The example that sticks in my mind was the testing of a certain engine and prop combination in an aluminium airframe. The combination promptly destroyed itself in testing, catching the engineers completely by surprise. The engine and prop combination was then tested in a different airframe with absolutely no problems. Then the original airframe was tested with another different engine and prop combination again no problem. Go figure, everything has a resonant frequency?

Last edited by Oracle1; 22nd Dec 2014 at 03:06.
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