Jabiru engine failures
If this was the big end of town, e.g. an airline suffering premature engine failures, the authorities would impose a reduced overhaul time limit and give the operator x number of hours or y months or even years to get it sorted. Maybe impose additional inspections meantime. But they would hardly dare totally grounding the fleet on the basis of a few failures. Even when Boeing suffered the fatal B737 rudder hardover problems some years back, and the later centre fuel tank explosions in both the 747 and 737, fleets did not get grounded. Procedures and inspections were put in place to mitigate the risk.
Halving a Jabiru engine TBO would have the effect of adding about 15 bucks an hour to the cost spread over the life of the engine. Most owners could absorb that or schools could pass it on to their students without too much pain. Provided reasonable notice to comply was given, of course.
This would be far preferable to the kneejerk reaction of virtually grounding the things without notice.
Halving a Jabiru engine TBO would have the effect of adding about 15 bucks an hour to the cost spread over the life of the engine. Most owners could absorb that or schools could pass it on to their students without too much pain. Provided reasonable notice to comply was given, of course.
This would be far preferable to the kneejerk reaction of virtually grounding the things without notice.
Last edited by Mach E Avelli; 23rd Nov 2014 at 10:08.
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If that results in the whole of the aviation industry collapsing,
Stiff.... aint their problem.
Stiff.... aint their problem.
You are preaching to the converted, AndyRR.
I did say, earlier in this thread, that the better approach to this issue would be to ascertain facts and cause...
I was hoping, perhaps as an act of purest optimism, that given the number of these engines that are being run out there, someone in pprune land would have some basic tech data on basic parameters such where the carburettor/induction system is designed and tested to put the cylinders on the lean curve.
The existence of a modification permitting manual leaning suggests that someone is playing with this stuff and may have some useful data.
I did say, earlier in this thread, that the better approach to this issue would be to ascertain facts and cause...
I was hoping, perhaps as an act of purest optimism, that given the number of these engines that are being run out there, someone in pprune land would have some basic tech data on basic parameters such where the carburettor/induction system is designed and tested to put the cylinders on the lean curve.
The existence of a modification permitting manual leaning suggests that someone is playing with this stuff and may have some useful data.
But in the weird and whacky world of aviation in Australia, 'discussions' are generally unhindered by trivialities like facts and cause.
Tootle pip!!
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Half cocked
I have written to my federal MP with this. I may have gone off half-cocked and with crackd clys but I'd encourage everyone with an interest to do likewise.
Writing to your local LiberalLabor Party MP isn't going to help. They are the problem. Their slavish and corrupt dedication to the principles of globalism, world free trade and lining their own pockets by selling state assets to their mates means they are powerless to enforce honest government
Criminals, most of them.
creampuff, it matters not what the cause of the Jabiru failures actually is, still less that there is most likely a solution.
CASA has decided to put Jabiru and the RAA out of business, it matters not what Jabiru say now. All CASA has to do is delay any further discussion until December 25th then Jabiru won't reopen in 2015.
To put it another way nothing that that Barrier, Polar and many others ever meant a thing. Unless its quashed right now Jabiru is finished, to be followed by the experimental fleet in short order.
CASA has decided to put Jabiru and the RAA out of business, it matters not what Jabiru say now. All CASA has to do is delay any further discussion until December 25th then Jabiru won't reopen in 2015.
To put it another way nothing that that Barrier, Polar and many others ever meant a thing. Unless its quashed right now Jabiru is finished, to be followed by the experimental fleet in short order.
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I am a little bit torn,
CASA publish their update with this little snippet 'CASA acknowledges that Jabiru has enjoyed a good reputation for manufacturing safe and reliable engines, and that most Jabiru-manufactured engines continue to operate safely and reliably, in Australia and abroad.'
we all know the quality of a lot of the CASA people involved in this sort of debacle.
however having been involved a little with Jab engines I would not be sending my gran or kids up in a Jab powered aircraft either.
I believe that had Jabiru been a lot more informative over the years with the various defects that have occurred then things might be better now.
I have experienced relatively new cyl heads requiring valves recut due to slight warping, cyl head temp appears very crucial. the leaky induction tubes that have an o-ring and large quantity's of goop probably play a part too. their bottom end appears unbreakable, electric system a bit ho hum.
I wish them luck
CASA publish their update with this little snippet 'CASA acknowledges that Jabiru has enjoyed a good reputation for manufacturing safe and reliable engines, and that most Jabiru-manufactured engines continue to operate safely and reliably, in Australia and abroad.'
we all know the quality of a lot of the CASA people involved in this sort of debacle.
however having been involved a little with Jab engines I would not be sending my gran or kids up in a Jab powered aircraft either.
I believe that had Jabiru been a lot more informative over the years with the various defects that have occurred then things might be better now.
I have experienced relatively new cyl heads requiring valves recut due to slight warping, cyl head temp appears very crucial. the leaky induction tubes that have an o-ring and large quantity's of goop probably play a part too. their bottom end appears unbreakable, electric system a bit ho hum.
I wish them luck
The final nail was CAsA's perception of their inaction on the Jabiru engine "issue", and they played directly into that CAsA perception by their own figures on failures - talk about an own goal.
Speaking of own goals, Jabiru themselves have not handled this well. It may well be that they've listened to their customers and fixed the through bolt and valve train issues - but if that's the case, they've communicated it abysmally.
It matters not what they say now, but there was a moment in time when they could have captured the high ground .......
CASA publish their update with this little snippet 'CASA acknowledges that Jabiru has enjoyed a good reputation for manufacturing safe and reliable engines, and that most Jabiru-manufactured engines continue to operate safely and reliably, in Australia and abroad.'
To put it another way nothing that that Barrier, Polar and many others ever meant a thing. Unless its quashed right now Jabiru is finished, to be followed by the experimental fleet in short order.
Where did you hear that Sunny and aren't you building an experimental aircraft right now?
Sqwawk7700, it may never be registered the way things are playing now. It has cost me about $85,000 so far, and probably another $10,000 for radios, transponder, paint and incidentals to come, but it has been worth it for the Three years of therapy building it has given me while my partner was dying of cancer.
I can afford to put a chainsaw through the airframe if I have to.
My recent experience of flying schools, flying clubs, etc. is that they are
far from happy places these days either and the stress levels of the RAA and SAAA are way up in my opinion thanks to deliberate CASA destabilisation.
The Jabiru event is as far as I can tell the opening shot in the final battle to destroy private and GA in favour of property development and jobs for life for former RAAF pilots.
My own personal question is "is it worthwhile to persist in aviation when it is clear that every mans hand is raised against it?" Anyway I'm having a few weeks off in Thailand at present, tomorrow I'm chartering a forty foot yacht for a week.
As for the SAAA, it now exists at CASA's pleasure if the Jabiru extinction is allowed to stand because it sets a precedent that any asset can be targeted anytime, anywhere and for any reason with only a little file stacking required to convince the Lilly livered AAT.
The SAAA is vulnerable because it exists thanks to a series of exemptions to regulations that must be renewed by CASA every Two years. The most important currently is the exemption permitting owner/builder maintenance. CASA had a "trial run" last year(?). And let the exemption expire without renewal for a few weeks - causing massive heartburn and probably a few heart attacks among grounded owners.
To put that another way, CASA can kill that sector by doing absolutely nothing- just decline to issue new exemptions.
I can afford to put a chainsaw through the airframe if I have to.
My recent experience of flying schools, flying clubs, etc. is that they are
far from happy places these days either and the stress levels of the RAA and SAAA are way up in my opinion thanks to deliberate CASA destabilisation.
The Jabiru event is as far as I can tell the opening shot in the final battle to destroy private and GA in favour of property development and jobs for life for former RAAF pilots.
My own personal question is "is it worthwhile to persist in aviation when it is clear that every mans hand is raised against it?" Anyway I'm having a few weeks off in Thailand at present, tomorrow I'm chartering a forty foot yacht for a week.
As for the SAAA, it now exists at CASA's pleasure if the Jabiru extinction is allowed to stand because it sets a precedent that any asset can be targeted anytime, anywhere and for any reason with only a little file stacking required to convince the Lilly livered AAT.
The SAAA is vulnerable because it exists thanks to a series of exemptions to regulations that must be renewed by CASA every Two years. The most important currently is the exemption permitting owner/builder maintenance. CASA had a "trial run" last year(?). And let the exemption expire without renewal for a few weeks - causing massive heartburn and probably a few heart attacks among grounded owners.
To put that another way, CASA can kill that sector by doing absolutely nothing- just decline to issue new exemptions.
Last edited by Sunfish; 23rd Nov 2014 at 13:20.
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Jabiru's Response
26th November 2014
Hello Jabiru Fleet,
As you are aware CASA has issued a draft proposal to place operational limitations on Jabiru Aircraft.
At a regulatory level Jabiru are communicating with CASA management and the Minister. CASA’s proposed document is virtually unprecedented in content and approach. We have sent our response. In summary:-
“The proposed instrument concerning operating limitations for Jabiru powered aircraft should be withdrawn immediately and without reservation.”
At an operational level we are having regular talks with CASA and the RA-Aus to improve communications and develop better methods and processes for managing the relationship between Regulator, Administrator and Manufacturer. At heart we all want a vibrant, active and safe recreational aviation sector and Jabiru are committed to doing what we can to achieve this.
At a technical level Jabiru’s engineers and staff are liaising with their CASA contacts and are making steady progress working through the items on the technical agenda. For many obvious reasons Jabiru does not conduct R&D in public nor publish every internal engineering report, however in the last 12 months 153 drawing revisions have been made along with revisions to many operating, maintenance, technical and overhaul manuals. 3 Service Letters or Bulletins (or their LSA category equivalents) have been published and 25 people have visited Jabiru for maintenance training. All of this work has been carried out with the one goal of improving the reliability and ultimately the safety of our products.
At a grass-roots level we have contacted many operating flying schools, asking them for information which will help us gather essential data to assess the currency of their configuration. This information will form a very important tool for us and we strongly urge people to take the time to provide the information as fully as possible. We are also appealing to people to keep flying and enjoying their aircraft!
Overall, Jabiru is moving forward and embarking on a program of positive changes. You will see regular technical and engineering updates for engines and airframes. Jabiru conducts engine maintenance courses and we will run more courses, more often. Communications at all levels will be improved.
In accordance with the CASA website the consultation period on the proposed instrument has been extended until 27 November 2014 and all submissions should be forwarded to [email protected] - Only 1 day left!
While Jabiru and the RA-Aus work on the formal agenda with CASA we encourage members, businesses, owners and operators to contact federal and local members of parliament to provide input regarding the CASA imposed restrictions, detailing potential financial impacts or distress, loss of potential customers, negative effects on employment, reputational damage, etc. Your federal member details can be found at Home ? Parliament of Australia with state and local details available at the relevant government website.
Finally, some food for thought: Records given to CASA for this year indicated 40 engine incidents. Of these incidents there have been twelve engine stoppages in flight resulting in forced landings. No serious injuries or fatalities were recorded. Nearly 41,800 hours were flown in Jabirus in Australia in that time with 92,700 flights.
It has been a very difficult and stressful time for Jabiru and it’s not over yet. However, as we drove to work today we saw a 20-year-old Jabiru LSA flying circuits and training its latest pilot. It helps to know that that little plane has probably trained at least 200 people in its life so far, that there are plenty of Jabirus in schools worldwide and there are a lot of smiles per hour happening because of Jabiru. That’s what we’re here for.
Hello Jabiru Fleet,
As you are aware CASA has issued a draft proposal to place operational limitations on Jabiru Aircraft.
At a regulatory level Jabiru are communicating with CASA management and the Minister. CASA’s proposed document is virtually unprecedented in content and approach. We have sent our response. In summary:-
“The proposed instrument concerning operating limitations for Jabiru powered aircraft should be withdrawn immediately and without reservation.”
At an operational level we are having regular talks with CASA and the RA-Aus to improve communications and develop better methods and processes for managing the relationship between Regulator, Administrator and Manufacturer. At heart we all want a vibrant, active and safe recreational aviation sector and Jabiru are committed to doing what we can to achieve this.
At a technical level Jabiru’s engineers and staff are liaising with their CASA contacts and are making steady progress working through the items on the technical agenda. For many obvious reasons Jabiru does not conduct R&D in public nor publish every internal engineering report, however in the last 12 months 153 drawing revisions have been made along with revisions to many operating, maintenance, technical and overhaul manuals. 3 Service Letters or Bulletins (or their LSA category equivalents) have been published and 25 people have visited Jabiru for maintenance training. All of this work has been carried out with the one goal of improving the reliability and ultimately the safety of our products.
At a grass-roots level we have contacted many operating flying schools, asking them for information which will help us gather essential data to assess the currency of their configuration. This information will form a very important tool for us and we strongly urge people to take the time to provide the information as fully as possible. We are also appealing to people to keep flying and enjoying their aircraft!
Overall, Jabiru is moving forward and embarking on a program of positive changes. You will see regular technical and engineering updates for engines and airframes. Jabiru conducts engine maintenance courses and we will run more courses, more often. Communications at all levels will be improved.
In accordance with the CASA website the consultation period on the proposed instrument has been extended until 27 November 2014 and all submissions should be forwarded to [email protected] - Only 1 day left!
While Jabiru and the RA-Aus work on the formal agenda with CASA we encourage members, businesses, owners and operators to contact federal and local members of parliament to provide input regarding the CASA imposed restrictions, detailing potential financial impacts or distress, loss of potential customers, negative effects on employment, reputational damage, etc. Your federal member details can be found at Home ? Parliament of Australia with state and local details available at the relevant government website.
Finally, some food for thought: Records given to CASA for this year indicated 40 engine incidents. Of these incidents there have been twelve engine stoppages in flight resulting in forced landings. No serious injuries or fatalities were recorded. Nearly 41,800 hours were flown in Jabirus in Australia in that time with 92,700 flights.
It has been a very difficult and stressful time for Jabiru and it’s not over yet. However, as we drove to work today we saw a 20-year-old Jabiru LSA flying circuits and training its latest pilot. It helps to know that that little plane has probably trained at least 200 people in its life so far, that there are plenty of Jabirus in schools worldwide and there are a lot of smiles per hour happening because of Jabiru. That’s what we’re here for.
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Accused?
It is for certain. And they know it. Problem is the mud thrown will stick despite the many design changes and improvements that have been introduced in recent times. The major ones I was not even aware of.
Doing some research of my own unlike CASA, proved very interesting indeed. Time will tell how these changes will go in the field.
It is for certain. And they know it. Problem is the mud thrown will stick despite the many design changes and improvements that have been introduced in recent times. The major ones I was not even aware of.
Doing some research of my own unlike CASA, proved very interesting indeed. Time will tell how these changes will go in the field.
"Accused". A very tame responce indeed by folk who appear more wary of their position than their obligations to their members.
Sometimes I wish RAA, AOPA and the like would say it how it is instead of trying the appeasing gently gently approach.
Sometimes I wish RAA, AOPA and the like would say it how it is instead of trying the appeasing gently gently approach.
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The Link to Australia's light aircraft association
CASA accused of 'misconduct' by Australia's light aircraft association - 12/1/2014 - Flight Global
CASA accused of 'misconduct' by Australia's light aircraft association - 12/1/2014 - Flight Global
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Some interesting reading:
Air/ fuel Ratio
In most spark ignition, internal combustion engines, the mixture is combustible within an AFR (air/fuel ratio) range of roughly 9 to 1 to about 17 to 1. 9 being very rich, 17 being very lean. 14.7 is the stoichiometric ratio (chemically correct) for lowest emissions. Best power is obtained at around 12.5 for most naturally aspirated engines.
Pistons
Most automotive engines produced today have cast aluminum pistons as opposed to forged aluminum pistons used in race applications where engines produce high continuous hp levels. Forged pistons transfer heat much faster than cast ones and retain their strength at higher temperatures however, the increased fitting clearances required makes them an unattractive choice for production car engines where noise, emissions and longevity are important and the average hp is relatively low in the automotive application. Aluminum loses approximately 50% of its strength at 400F and this is a pretty typical temperature for a piston crown operating at medium to high power settings. The strength rapidly diminishes above 500-550F so they cannot be allowed to get this hot or deformation and fatigue will set in due to the high pressure they are subjected to. In other words, they can become somewhat plastic and weak if they get too hot.
Pistons are usually the first parts to fail from excessive thermal loads on automotive engines. The solution to this for almost all auto OEMs is to run the AFR very rich at WOT (wide open throttle) and high rpms corresponding to high hp output. The excess fuel drops the combustion temperatures, EGTs and cools the piston crowns themselves, keeping them within their safe thermal limits. While best power is obtained with AFRs around 12.5, most OEMs run the AFRs at between 10.5 to 11.2 at WOT. This is where you need to tune your AFRs also. While there will be a slight hp loss and you'll use more fuel, this is the only way the pistons will survive for very long running at continuous high power settings. I suggest a nominal target of 10.5 to 11.0 for power settings above about 75% and no leaner than 11.5 from 50% to 75% power. I'd also mention that detonation is most likely to happen at AFRs of around 12.5 as well if there is excessive spark timing and/or low octane fuel.
Valves
Automotive engine valves and seats vary in material and quality between engine types and brands. Again, these parts have thermal limits and high EGTs can decrease the life of these components. Rich mixtures decrease EGTs and exhaust valve temperatures. While most valve failures are slow and gradual compared to piston failures, we don't want degradation here either.
We have the capability of checking Lamda against EGT, never thought of doing this might be interesting to see the relation between the two.
Air/ fuel Ratio
In most spark ignition, internal combustion engines, the mixture is combustible within an AFR (air/fuel ratio) range of roughly 9 to 1 to about 17 to 1. 9 being very rich, 17 being very lean. 14.7 is the stoichiometric ratio (chemically correct) for lowest emissions. Best power is obtained at around 12.5 for most naturally aspirated engines.
Pistons
Most automotive engines produced today have cast aluminum pistons as opposed to forged aluminum pistons used in race applications where engines produce high continuous hp levels. Forged pistons transfer heat much faster than cast ones and retain their strength at higher temperatures however, the increased fitting clearances required makes them an unattractive choice for production car engines where noise, emissions and longevity are important and the average hp is relatively low in the automotive application. Aluminum loses approximately 50% of its strength at 400F and this is a pretty typical temperature for a piston crown operating at medium to high power settings. The strength rapidly diminishes above 500-550F so they cannot be allowed to get this hot or deformation and fatigue will set in due to the high pressure they are subjected to. In other words, they can become somewhat plastic and weak if they get too hot.
Pistons are usually the first parts to fail from excessive thermal loads on automotive engines. The solution to this for almost all auto OEMs is to run the AFR very rich at WOT (wide open throttle) and high rpms corresponding to high hp output. The excess fuel drops the combustion temperatures, EGTs and cools the piston crowns themselves, keeping them within their safe thermal limits. While best power is obtained with AFRs around 12.5, most OEMs run the AFRs at between 10.5 to 11.2 at WOT. This is where you need to tune your AFRs also. While there will be a slight hp loss and you'll use more fuel, this is the only way the pistons will survive for very long running at continuous high power settings. I suggest a nominal target of 10.5 to 11.0 for power settings above about 75% and no leaner than 11.5 from 50% to 75% power. I'd also mention that detonation is most likely to happen at AFRs of around 12.5 as well if there is excessive spark timing and/or low octane fuel.
Valves
Automotive engine valves and seats vary in material and quality between engine types and brands. Again, these parts have thermal limits and high EGTs can decrease the life of these components. Rich mixtures decrease EGTs and exhaust valve temperatures. While most valve failures are slow and gradual compared to piston failures, we don't want degradation here either.
We have the capability of checking Lamda against EGT, never thought of doing this might be interesting to see the relation between the two.