jetjr Posted February 13, 2016 Share Posted February 13, 2016 Could be talking about the report into recreational LSA engines A draft was released 2014 so guess final would be due now sometime The data in here conflicts with CASA and assuming it doesnt change dramatically, Rotax 912 pwners will be in for serious trouble too, 2.7 time acceptable limit on failures CASA worse trouble as Jabiru only 30% worse NOT 300% Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 ATSB have a higher need for non bias, (impartiality) than CASA. They are supposed to be entirely independent from any one .. Government, CASA and any entity operating in the transport business. Nev Link to comment Share on other sites More sharing options...
jetboy Posted February 13, 2016 Share Posted February 13, 2016 You've touched on an important point here Bruce, and I've meant to make a point about it earlier.In most clean cut self regulation/self liability where an industry as at arms length from the government, the time taken from when the self administrator discovers a risk to the time taken for exclusion of that risk is up to the self administrator/company/etc. Two of the disadvantages when the government has a little experiment with part prescription/part self administration are: 1. The liability for their decisions is usually theirs - so, once again they stand to pay out money if they are negligent. 2. Any unreasonable delays in identifying a non compliance to a prescribed rule, and any unreasonable delays in declaring the non-compliance over, may involve them in pay out costs. That's not legal advice, and nor is anything else I say on this forum, just something I think hasn't really been looked at by governments and the bodies they set up. one aspect in the video about CASA not knowing what was wrong with any of the engines..... and that they state that these engines are under LSA rules, not the average light aircraft or homebuilt certification rules -therefore the responsibility of Jabiru to find the cause and issue any modifications to make the engines OK again......and Jabiru hasnt told them what the problems are so they are still sitting on it .... 14 months on ... I thought that was a very misleading statement to be made Wouldnt the majority of Jab engines and aircraft sold and operating in Aus be made to the design rules systems in place before ASTM and LSA was introduced ? Do you have a registration category specifying ASTM compliance? In NZ I dont think there are any aircraft or engines on the register operating under LSA requirements. They might well be compliant, but to be registered as a microlight or GA aircraft they must meet one of the other design rules already in existence. LSA is irrelevant. Ralph Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 the urgency is going to be on finalising what trigger will be required to get affected Jabiru engines back to normal operations asap. And that may be very difficult without good data on what triggered the restrictions. CASA have painted themselves into a corner where lifting the restrictions might be very difficult. They have to either: - Come up with some metric for Jabiru to reach to justify lifting the restrictions. This will have to be something that Jabiru didn't previously measure up to, that other engines DID, where Jabiru can demonstrate a change. This is essentially what people have been asking for when asking for justification for the restrictions - a measure to meet to have them lifted or - Demonstrate that the rate of engine failures has decreased statistically. Given the low number of occurrences overall, and the fact that you need statistics over over a reasonable lifetime in a range of operations, it will probably take 5-10 years to get statistically valid data. These statistics would obviously also have to be a measure where Jabiru failed and other engines passed. CASA might have a problem where they can't produce a trigger for lifting the restrictions without providing evidence that the restrictions were not justified i.e. other engines must also pass the same test. A note on statistics: Statistics is more than a count of occurrences or even a set of data. Statistics is a set of tools to tell you whether you can draw reliable conclusions from your data. If you have data with the number of Jabiru failures and the number of other engine failures, the science of statistics can tell you whether you have enough data to draw a conclusion and how reliable that conclusion is. I haven't seen anything like this produced. I have my doubts whether CASA actually employ anyone with statistics qualifications. 2 Link to comment Share on other sites More sharing options...
Ron5335 Posted February 13, 2016 Share Posted February 13, 2016 Did you note during the video. The CASA dude proudly put forward the figure of 2 to 3 times greater rate of failure ( To back up their actions) but then Sen. Heffernan replied so we are talking about 2 or 3 planes per 10,000 (Instead of 1) It kind of puts everything into perspective. Link to comment Share on other sites More sharing options...
Oscar Posted February 13, 2016 Share Posted February 13, 2016 CASA might have a problem where they can't produce a trigger for lifting the restrictions without providing evidence that the restrictions were not justified i.e. other engines must also pass the same test. Both the Jab 2200J and the Rotax 912A were certificated under JAR 22H, so any A/D on them would be a CASA responsibility. Later Jab 2200 and I think all of the 3300 engines are certified under ASTM, as are some of the R0tax 912s. Some more recent versions of the 912 are certificated under FAR 23. So it's not a simple issue and Aleck's responses were, at the least, a gloss over the situation. And I believe your summary is 100% correct: CASA has painted itself into a corner. It beggars belief that Jonathan Aleck was so stupid as to not see this outcome coming down the tunnel as a flame-thrower - unless this outcome was something he desired to happen. Both the timing AND the shambolic assembly of 'data' simply reeks of what Phelan called 'an unseemly haste' (a title far more dignified than the circumstances deserve) to have the Instrument IN PLACE and EFFECTIVE before Skidmore took over the DAS position. If this goes to a Senate Inquiry - and it most certainly should - this is going to reverberate for quite some time. Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 Funny they had a legal expert rather than a technical one. I think they have problems but that was obvious from day ONE. How to get out of this.... Even blaming a "fall" guy won't work (and it usually does). They have set goalposts nobody knows what they look like. No one knows what CASA need to reach their benchmark performance and it looks like they have stuffed up the figures. If an engine is only 30% worse than the best, that really isn't a lot especially if you consider the fact the Jabiru is aircooled and has less tolerence for fuel and tuning variations, (as do all other aircooled engines). the later Rotax engines may not be as user friendly as the 80 HP versions and of course as the Rotax engines get older they become a little less reliable as all things do. They also have to be retired after a time from installation (or purchase) I'm not sure which and it's nearly twice the price and the parts are not cheap. The reason you have to land unplanned is not necessarily a dramatic event. A broken Carb mount rubber will do it as well as a dropped valve. Nev 1 2 Link to comment Share on other sites More sharing options...
turboplanner Posted February 13, 2016 Share Posted February 13, 2016 And that may be very difficult without good data on what triggered the restrictions. CASA have painted themselves into a corner where lifting the restrictions might be very difficult.They have to either: - Come up with some metric for Jabiru to reach to justify lifting the restrictions. This will have to be something that Jabiru didn't previously measure up to, that other engines DID, where Jabiru can demonstrate a change. This is essentially what people have been asking for when asking for justification for the restrictions - a measure to meet to have them lifted or - Demonstrate that the rate of engine failures has decreased statistically. Given the low number of occurrences overall, and the fact that you need statistics over over a reasonable lifetime in a range of operations, it will probably take 5-10 years to get statistically valid data. These statistics would obviously also have to be a measure where Jabiru failed and other engines passed. CASA might have a problem where they can't produce a trigger for lifting the restrictions without providing evidence that the restrictions were not justified i.e. other engines must also pass the same test. A note on statistics: Statistics is more than a count of occurrences or even a set of data. Statistics is a set of tools to tell you whether you can draw reliable conclusions from your data. If you have data with the number of Jabiru failures and the number of other engine failures, the science of statistics can tell you whether you have enough data to draw a conclusion and how reliable that conclusion is. I haven't seen anything like this produced. I have my doubts whether CASA actually employ anyone with statistics qualifications. The summary of the exchange with the Senators is that CASA used the FAA benchmark to trigger their action. There's not a lot of point in us continuing the discussion on what those figures were, until CASA releases the figures used in the final discussion and management decision, and I don't believe we have seen those figures yet. If the FAA benchmark was used to trigger the action, then logically to end the action the "occurrences" need to drop below the trigger point. Link to comment Share on other sites More sharing options...
Camel Posted February 13, 2016 Share Posted February 13, 2016 Prepare for the worst........the whole saga was flawed, from the beginning. The "spin doctors" may pull a rabbit out of their hat here. They have to, it's that serious to them.( getting "exposed" is their worst nightmare, come true ) More likely to pull a Hare out of their backside. Link to comment Share on other sites More sharing options...
Oscar Posted February 13, 2016 Share Posted February 13, 2016 The summary of the exchange with the Senators is that CASA used the FAA benchmark to trigger their action.If the FAA benchmark was used to trigger the action, then logically to end the action the "occurrences" need to drop below the trigger point. CASA used the FAA benchmark all right - but stuffed up the actual application of the benchmark to the figures. O'Sullivan has - I am reasonably sure - analysis of this, and if it comes to a Senate Inquiry, will draw and quarter CASA on this point. CASA has already hung itself, so it is only the subsequent actions that need to be completed. Link to comment Share on other sites More sharing options...
Guest asmol Posted February 13, 2016 Share Posted February 13, 2016 I would be surprised if the ATSB would leak the results of a report before its official release. Its not a leak, like most things aviation it goes through a consultation process before its released (I was told) You can bet money CASA and RA-Aus have seen it before the official ATSB release (and probably made comments as well) Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 If the FAA benchmark was used to trigger the action, then logically to end the action the "occurrences" need to drop below the trigger point. What FAA benchmark were they referring to? Assuming there is such a benchmark, there are still 2 problems: 1) What if other engines e.g. 2 stroke Rotax, VW conversion etc. also don't meet the FAA benchmark? 2) How long does it take to demonstrate that you do meet the benchmark? This is what I was saying might take 5-10 years of figures to produce valid statistics. When numbers are low, you get a natural variation in figures. Just the other day on the news they were saying that this year 14 people have drowned on beaches this year when the equivalent figure last year was 7. Have the people responsible for beach safety made some big change that is causing people to drown, or more likely, is it just a particularly unlucky year? Link to comment Share on other sites More sharing options...
kgwilson Posted February 13, 2016 Share Posted February 13, 2016 Both the timing AND the shambolic assembly of 'data' simply reeks of what Phelan called 'an unseemly haste' (a title far more dignified than the circumstances deserve) to have the Instrument IN PLACE and EFFECTIVE before Skidmore took over the DAS position.If this goes to a Senate Inquiry - and it most certainly should - this is going to reverberate for quite some time. Phelans article published on 28 November 2014 was called "Indecent Haste" & it sums up the situation very well almost a month before CASA dropped the bomb on Jabiru so all the correct information was available to them well before the instrument became law. Their haste was well and truly indecent & there are plenty of other unprintable adjectives to describe their actions as well. See http://proaviation.com.au/2014/11/28/indecent-haste/ 1 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 Or perhaps more people are swimming on unpatrolled beaches. I saved one of my kids when he was about 10. I noticed he was tired and told him to get out. Next thing he is in a rip and heading for New Zealand. My daughter also drank a lot of salt water in the surf and spent a day in intensive care . Salt water is more dangerous than fresh due to osmosis. Could have lost both of them easily. I virtually grew up on the beach surfing, without a board. This is off topic so I won't run it further..Nev Link to comment Share on other sites More sharing options...
Oscar Posted February 13, 2016 Share Posted February 13, 2016 What FAA benchmark were they referring to? See: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/4ab3d0632e35843b86257b2d0058841c/$FILE/1999-00006.pdf Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 Or perhaps more people are swimming on unpatrolled beaches. The number seems unlikely to have doubled in 1 year. If there is a trend over several years you would look at it, but you can't conclude anything from those 2 figures. That's when statistics come in - you plug in the numbers over several years, and statistics can tell you how likely it is that this number is produced by chance. If it is unlikely to be produced by chance, then you need to start looking for causes. Link to comment Share on other sites More sharing options...
Oscar Posted February 13, 2016 Share Posted February 13, 2016 Phelans article published on 28 November 2014 was called "Indecent Haste" & it sums up the situation very well almost a month before CASA dropped the bomb on Jabiru so all the correct information was available to them well before the instrument became law. Their haste was well and truly indecent & there are plenty of other unprintable adjectives to describe their actions as well.See http://proaviation.com.au/2014/11/28/indecent-haste/ KG - Thanks for that clarification, I was relying on memory for the title and my memory isn't what... where was I? Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 Aro If it's a large number the variation could be large, as it is a small% that drown. It could be caused by hotter days or less advertising of the hazards or less swimming activities in schools or lack of supervision. (or a bit of a lot of factors) I'm not surprised young people drown on surf beaches. Most of them wouldn't know what a rip is or how to handle it, and it doesn't take long to get into difficulties. (This is slightly off topic so I won't run it further..)Nev Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 If it's a large number the variation could be large, as it is a small% that drown That's my point - without knowing the variation you can't conclude anything. The number on it's own is meaningless. 1 Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 See: http://rgl.faa.gov/Regulatory_and_G...2e35843b86257b2d0058841c/$FILE/1999-00006.pdf That's not a benchmark on failure rate, its a way of estimating failure rate from accident data. It is saying the numbers for engine power loss and shutdown are unreliable, and provides a way to estimate them from accident data - which is considered more reliable. According to that document, historically engine power loss/shutdown frequency is greater than 1 in 10,000 flight hours (doesn't specify how much greater). Their estimate of power loss/shutdown frequency is Number of accidents x 10 or Number of fatal accidents x 100. So it doesn't provide any actual benchmark. However, it does provide a way to estimate the number of engine failures across each engine type: the number of accidents x 10. The number of fatal accidents is probably too low use reliably. However there have been a number of fatal engine failure accidents behind Lycomings and Rotax, so using this methodology would suggest that those engines have a failure rate much higher than Jabiru. Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 If you have already more or less decided something must be done, and then build a grab bag of data to substantiate your actions from a convenient and quickly found set of stats, you end up with what has happened here. The haste to proclaim the edict before a planned meeting seems ominous. It's not just by chance that these things happen. If ATSB don't do something maybe the Senate should . The process has to be above board.Nev Link to comment Share on other sites More sharing options...
Oscar Posted February 13, 2016 Share Posted February 13, 2016 That's not a benchmark on failure rate, its a way of estimating failure rate from accident data. It is saying the numbers for engine power loss and shutdown are unreliable, and provides a way to estimate them from accident data - which is considered more reliable.According to that document, historically engine power loss/shutdown frequency is greater than 1 in 10,000 flight hours (doesn't specify how much greater). Their estimate of power loss/shutdown frequency is Number of accidents x 10 or Number of fatal accidents x 100. So it doesn't provide any actual benchmark. However, it does provide a way to estimate the number of engine failures across each engine type: the number of accidents x 10. The number of fatal accidents is probably too low use reliably. However there have been a number of fatal engine failure accidents behind Lycomings and Rotax, so using this methodology would suggest that those engines have a failure rate much higher than Jabiru. Absolutely correct - and CASA has put another noose around its head by claiming that it has relied on the NTSB figures ( see Jonathan Aleck's response, probably following the information given in a letter from one of the Sports Aviation unit staff..) Applying the NTSB formula CORRECTLY, produces: the GA fatality rate in the USA is 1.14 fatal accidents per 100 000 hours flown (2010). Using the FAA guidance material this translates to an event rate of 11.4/10 000 hours flown. Jabiru aircraft rate given of 5.8/10 000 hours now looks good at ½ the GA rate. This shows how using the number in the FAA guidance material as a benchmark, in the CASA justification, is flawed. Link to comment Share on other sites More sharing options...
aro Posted February 13, 2016 Share Posted February 13, 2016 That document gives a methodology to estimate the number of engine failure events from the number of fatal accidents. although I'm not convinced by it since the relative performance of the aircraft influences so heavily. I went back to the ATSB database and queried the last 10 years of engine failure related fatal accidents. The numbers: Lycoming or Continental: 4 Rotax: 3 Jabiru: 1 VW: 1 Auto: 1 Gipsy: 1 Which using the methodology (multiply by 100 and divide by 10 years) gives estimated engine failure event rate of: Lycoming/Continental 40 / year Rotax: 30 / year Jabiru/VW/Auto/Gypsy Major each 10 / year. I would say these figures are rubbish due to the low number of data points. Also Lycoming/Continental figures are definitely influenced by the higher performance of the aircraft they are installed in - but this does reflect the real risk. Rotax vs Jabiru is interesting although would be greatly influenced by 1 accident either way. 10 x the number of accidents might give better figures but I don't have the time at the moment. Link to comment Share on other sites More sharing options...
facthunter Posted February 13, 2016 Share Posted February 13, 2016 It has to be per 1,000 hours or per 1,000 flight cycles or similar. Nev Link to comment Share on other sites More sharing options...
jetjr Posted February 13, 2016 Share Posted February 13, 2016 TP As we have said again and again we DO have the data they worked upon Maybe you dont but others do The benchmark quoted was 1 failure per 10,000 flight hours. Id have thought that was a very low figure and would guess it applied to certificated engines costing much more Then again what about already certificted Jabiru engines? Even if Jabiru come up with miracle fix they cant implement it. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now