ATSB report into light aircraft engine failures

[aro]

Anyone can make any set of numbers have a result of whatever you want....I have seen 1 + 1 = 0 and it all looked correct to me. This is where its all a crock. The fact of the matter is there is a lot of jabiru engines out there that have gone bang. This is a fact! there are a lot of Rotax engines out there and not so many have gone bang this is also a fact. There are GA engines out there and they go bang too.

It's also a fact that more people have died after Rotax engine failures than Jabiru. It might even be true. Without actually looking in detail at the numbers - which we are trying to do - you can't be sure. Just because you are aware of more Jabiru failures, or heard it at the airport, or read about Jabiru failures on the internet doesn't make it true. Personally I know about more Rotax failures (also I believe unreported) than Jabiru but one person's personal knowledge is just an anecdote. You have to look at the numbers - and not just for numbers that support what you are trying to prove. You need to spend more time looking for numbers that might refute it.

 

In 30 years of flying I cant remember one case of a 912/912S having a serious engine malfunction - the only stoppages I can recall were due to faulty maintenance on the part of the owner. My earlier aircraft, a Jodel D18 with a 912S suffered an engine failure (over water but within gliding distance of land and the forced landing was very skillfully executed by my co-pilot into a small paddock on the coast) - however it turned out that I had not secured the balance tube between the carbs properly. It came off and the engine stopped immediately. My fault entirely, and after resecuring it, we took off again.

The old "I've never had an engine failure and they were not the engine's fault anyway" routine. This is why you need to look carefully at the numbers and work out what should be included and what shouldn't. Are maintenance related failures excluded from the Jabiru figures? Should Jabiru get any credit for eliminating any possibility of a balance tube problem? (Or all carb synchronization related problems for that matter?)

 

All I can be sure of is that for me and me alone my backside will never be in a jab powered aircraft until they sort their sh*t out.

I normally fly a Rotax but have no issues flying in a Jabiru. I would be far more reluctant to fly in a piston twin - I think PA-31s have killed more people due to engine failure in Australia than Jabirus.

 

 

[Kyle Communications]

Aro

 

The survivability rate for the Jab airframe maybe quite high compared to all the other airframes that are Rotax powered that have fatalities etc...plus you have no idea at what height the failures were or anything else....so it really is also a moot point

 

As far as personal opinion goes...my first job for a year when I got out of school was at the Brisbane Ford Motor Comapny assembly plant. We built the XC falcon sedans,wagons and utes.....I would never own a Ford after working there.....this doesnt mean the same stuff doesnt go on at the GMH factory but at least I didnt see it happen.....my opinion on Jab engines is the same, I maybe just a old school pig headed old fart taking that view....but I can sleep at night with all of those decisions, rightly or wrongly

 

 

[fly_tornado]

I really am open to all sides of this argument but I am getting sick of trollish type comments that add absolutely nothing of substance to the debate.

when this thread is 30 pages long you'll wonder why you thought it was going to change anything

 

 

[planesmaker]

Thecurrent Jab airframes with Rotaxengines which are only a few aretoo nose heavy and I have seen this first hand and spoken to the pilots and owners of that aircraft base at Caboolture...which I think hasbeen sold now. Jab need to make the necessary mods to make itcorrect for W&B then it would be a great bit of kit

 

Mark, my rotax j400 came out balanced spot on. The j160/170maybe different but put a rotax in a j230 and they will sell a lot more than they are now

 

Tom

 

 

[Yenn]

Kyle. I worked at GMH Pagewood plant foor my first job in Australia and vowed I would never buy a Holden, because of the damaged engines that were sold as new. Mayby BMW and Mercedes have the same problems.

 

 

[Oscar]

AroThe survivability rate for the Jab airframe maybe quite high compared to all the other airframes that are Rotax powered that have fatalities etc...plus you have no idea at what height the failures were or anything else....so it really is also a moot point

It is anything BUT a moot point - that is an expression borne of prejudice against a particular engine, not one coming from intelligent thought.

 

The restrictions on operation of Jabiru-powered aircraft by CASA have been 'substantiated' - or 'validated' by reference to statistics. The ATSB report - when considered in its entirety - makes it quite, quite clear that Jabiru engine 'high risk' failures / malfunctions are NOT exceptional, over a statistically significant period.

 

Now let's just look at the effects of the CASA limitation.

 

According to RAA representations to CASA at the time of consideration of imposition of the restrictions, around 60% of the entire RAA training fleet, relied on Jabiru aircraft. The ability of FTFs to deliver the full training schedule using Jabirus, has been castrated. Let's just look at what that means, realistically.

 

For FTFs to be able to offer the full range of flight training services for an RPC allowing solo flight x-country - they have to replace their Jabs. (now devalued) with non-Jab. engined, factory-built, aircraft. That means either: Lightwings, Brumbies (if they are still truly in the local market - it seems that has gone quiet recently, but maybe that is because I have no interest in them) or a Euro import.

 

There was a damn good reason that 60% of the FTFs chose Jabirus: cost of purchasing and operation. As a side benefit, they got an aircraft with the best safety record in the business, for the class ( and one of the best in the world for ANY vaguely comparable class). The cost/hour for RPC training using Jabiru aircraft, is ( or WAS) very attractive to new entrants to aviation.

 

Now, let's look at 'liability' issues - because those drive , in particular, insurance: a major cost for the operation of a commercial use of an RAA aircraft - either for an FTF or an owner defraying her/his costs of owning an aircraft by putting it on the line for hire/training use. Does anyone seriously think that the insurance companies, faced with the facts that non-Jabiru-engined aircraft have demonstrably a greater risk factor for fatality / serious injury, will NOT apply normal actuarial factors?

 

I'd be interested to hear your appreciation of the outcome of a Court case where a student pilot has been killed/injured when flying an aircraft that has a demonstrated higher risk of fatality/serious injury than a Jabiru. Want to bet that CASA won't be joined in the case, for having forced the FTF to utilise a less-safe aircraft?

 

Just on costs alone of operating a Jabiru for training vs. a more expensive aircraft: as costs increase, the numbers of participants will diminish. Fewer pilots equates to fewer air movements every year - and for marginal remote facilities, that could well mean that airfields we now enjoy will close down. Councils will sell off airfields. Privately-owned airfields that struggle to achieve a financial return enough to be maintained - won't be maintained. Fuel deliveries to airfields with low demand, won't happen.

 

If your hoped-for vision of RAA aviating in the future is high-cost, limited travel opportunity and a vanishing number of participants, then your position regarding the correctness of the impositions on Jabiru engines, is fair enough. You are entitled to whatever vision you hold. Personally, I'd like to see sports aviation blossom as an activity.

 

Don't just come back with a 'you are full of sh1t, Oscar' response- do us all a favour and at least present cogent arguments against my propositions. Because this is important - lest we find ourselves boxed into a situation where sport/recreational flying is reduced to a few hours a year looking repeatedly at the local view from an elevated position.

 

Or is that too hard for you?

 

 

[Oscar]

Thecurrent Jab airframes with Rotaxengines which are only a few aretoo nose heavy and I have seen this first hand and spoken to the pilots and owners of that aircraft base at Caboolture...which I think hasbeen sold now. Jab need to make the necessary mods to make itcorrect for W&B then it would be a great bit of kitMark, my rotax j400 came out balanced spot on. The j160/170maybe different but put a rotax in a j230 and they will sell a lot more than they are now

Tom

The J230 airframe has the length and weight of tailcone and the area of tailfeathers - particularly the elevator (to give control authority at the low end of the speed range)- plus the wing-tanks centred on the optimum c/g, to make the Rotax conversion extremely viable. The choice between converting to a Rotax 912/914 or converting to a CAE 3300 ( since both are not certified aircraft) would come down to cost of the conversion and a few kgs in useful load in favour of the CAE 3300. - but if operating out of high and hot country, he 914 has the odds in its favour.

 

 

[octave]

when this thread is 30 pages long you'll wonder why you thought it was going to change anything

I don't particularly think it will change anything, but most posters, whatever their view post detailed and researched information, whereas you (and I may be missing the subtleties of your posts) seem to really "get off" on the problems of Jab owners.

 

As I have already said, I have no direct stake in the CASA Jab controversy but I do have great sympathy for owners of Jab aircraft whereas you seem to enjoy their dilemma.

 

Personally I do not want to see any of my fellow aviators flying activities restricted unless it is absolutely necessary. I have no idea if Jab engines fail at a greater rate than Rotax 2 strokes (perhaps they will be next on CASAs list).

 

FT if you wish to contribute to this thread perhaps you could post technical information instead of your one liner jibes at your fellow aviators. I know it must be frustrating for you if you are unable to fly at the moment but please just try to get your point across without having a go at Jab owners or operators. (I say this as a life long Rotax guy)

 

 

[Kyle Communications]

Don't just come back with a 'you are full of sh1t, Oscar'

Oscar I never actually said you were full of sh*t. I said your figures are fancifull and you were posting drivel ( in my opinion). Everyone looks at figures and makes their own conclusions and this can be made on whatever preducious you have.

 

Your conclusions and mine differ quite a lot, I look at the numbers and see obviously something different to you.

 

IF you had read properly what I posted I said I would not consider a Jab engine in my new aircraft "UNTIL THEY SORT THEIR SH*T OUT". I would like nothing better to see Jab succeed with a great product. I KNOW how hard it is to make a good reliable product. I have been designing and building a lot of mass produced products and involved in many other products over the last 30 years in design and manufacturing methods and QA. I have recently designed a new product that thousands have gone out the door in the past 3 months these are not cheap units either they start around 1200 bucks and go upwards of 3000 each so we are not talking cheap items. We have had 0.5% come back with some issues ( 2 issues to be exact) even after almost 12 months of design, development and heavy abuse testing. Those issues have been fixed within 2 weeks and they go out the door all the better for it for the future.

 

Jab have known about all these issues for many years and seem to be very slow on any uptake to fix the issues in any quick time frame. Fixing any issue costs money and doing it quickly costs even more money with the necessary resources required to get it done in quick time. I believe they have never done their due dilligance in this regard

 

As far as the future of RAA and regulation or should I say over regulation. I want to see more aircraft and more pilots and less paperwork but everyone has to follow the rules that are set down. Currently some of those rules I believe are stupid or superfluous. I dont believe CASA should have anywhere near the control of the RAA that they do have. I think there has to be some crossflow between the organisations but CASA is a monster out of control and needs to be looked at in a very big way. Were they heavy handed in their decision with the Jab engine?. I believe that they would have seen or should have seen what was going on with failures a long time ago and basically didnt do much about it so when the ATSB stuck their nose in because of whatever reason that woke that giant up CASA had to be seen to be doing something so they jumped on it big time to show they were doing something....but then again maybe CASA have been talking to Jabiru about it as we are not privy to that information it would only be Rod Stiff and maybe a few others that would know that and Jab didnt take them seriously or just decided to do it in their own time...who knows. The sad thing is the amount of owners who have had their aircraft devalued a lot and up and coming pilots are hamstrung with training options can only be bad for our mode of flying.

 

My personal opinions are just that MY opinions and they are developed on what I read and what I see with my own beady eyes and seeing this is a free country still at this stage I am entitled to MY opinion .

 

 

[facthunter]

Less opinion and more facts would make this subject more likely to get somewhere. Jabiru have generally supported their product quite well over time. They do regard some users as part responsible for the problem and with this I would agree. I've found many "guru's" and operators to be less than well grounded in engine analysis usage. and general awareness than desired. No aero engine is a fit and forget object, unless it's electric maybe, and the fuel is a prime suspect for many of the problems. I didn't see any mention of that in the ATSB produced fact sheets.. Nev

 

 

[Kyle Communications]

Nev

 

My opinions are based on the facts shown in the ATSB report.

 

They only took into account mechanical and fracture failures NOT fuel starvation factors

 

I have endeavoured to put here a condensed version of the relevant facts stated in the report. My opinions are based on this data. I dont think I am a stupid man and anyone who looks at these figures and statement objectively would have to come up with a similar opinion

 

"Occurrence notifications associated with engine failure or malfunctions reported to either Recreational Aviation Australia (RAAus) or the ATSB between 2009 and 2014 were examined.1] Engine failures or malfunctions were only considered to be occurrences when they happened while the aircraft was boarded for flight. Fuel starvation and fuel exhaustion occurrences were not classified as engine failures or malfunction."

 

"In the set of 322 engine failures or malfunctions described in this report"

 

"Thirteen engine manufacturers were represented in the 322 engine failure or malfunction occurrences (see Figure 2). However, just four manufacturers made up 94.1 per cent of the entire set. These were:

 

• Jabiru (40.4%, 130 occurrences)
   
   
  
• Rotax (27.0%, 87 occurrences)
   
   
  
• Textron Lycoming (18.0%, 58 occurrences)
   
   
  
• Continental Motors (8.7%, 28 occurrences).
   
   
  

 

 

The remaining 5.9 per cent (19 occurrences) were made up of nine different engine manufacturers (and one unknown engine manufacturer). The remainder of the analysis will focus on the four aforementioned engine manufacturers."

 

"Taking into account the number of aircraft on both the CASA and RAAus registers and the number of aircraft involved in the above data, this represents an engine failure or malfunction occurrence in the study period in about:

 

• one in 10 aircraft with Jabiru engines
   
   
  
• one in 36 aircraft with Rotax engines
   
   
  
• one in 35 aircraft with Continental engines, and
   
   
  
• one in 33 aircraft Lycoming engines. "
   
   
  

 

 

"The engine failure or malfunction rates from Figure 3 are displayed in Figure 4 on a per year basis. Figure 4 shows that the total yearly engine failure or malfunction rates for the four primary engine manufacturers in the set has increased from 36 in 2009 to 65 in 2014. In 2009, reports of engine failures or malfunctions involving Lycoming engines were the most common with 15. However since then, reports from Jabiru powered aircraft have consistently shown the highest yearly rates."

 

This next set take into account the "safety factors" and from what I read do not affect the numbers quoted in the passages above

 

"Figure 7 shows the rates of technical failure mechanisms safety factors per 10,000 hours flown for the four major engine manufacturers. (Note that this figure is using safety factors, not occurrences, and some occurrences have multiple safety factors.)

 

Jabiru

 

• Nearly half (45%) of the safety factors associated with Jabiru engine failure or malfunctions (where the safety factor was known) were classified as fractures, leading to a rate of 1.11 fractures per 10,000 hours flown.
   
   
  
• Mechanical discontinuities were the next most common failure mechanism for Jabiru engines (38%, rate 0.94/10,000 hours).
   
   
  
• These were followed by electrical discontinuities (5%, rate 0.12/10,000 hours) and wear (2%, 0.05/10,000 hours).
   
   
  
• Non-technical issues accounted for 11%.
   
   
  

 

 

Rotax

 

• Safety factors relating to Rotax engine failure or malfunctions were predominantly due to mechanical discontinuities (46%, rate 0.39/10,000 hours).
   
   
  
• Fractures then made up 13 per cent (0.11/10,000 hours) followed by electrical discontinuities (6%, rate 0.05/10,000 hours) and corrosion issues (4%, rate 0.04/10,000 hours).
   
   
  
• Non-technical issues accounted for 19 per cent of the known Rotax safety factors.
   
   
  

 

 

Lycoming

 

• Electrical discontinuities where the most common technical failure mechanism for Lycoming engines with 33 per cent of the known safety factors, leading to a rate of 0.29 per 10,000 hours.
   
   
  

 

 

Continental

 

• At a rate of 0.17 per 10,000 hours and accounting for 20 per cent of known safety factors, fractures where the most common technical failure mechanism for Continental engines.
   
   
  
• However, engine failure or malfunction occurrences with Continental engines had by far the highest proportion of non-technical contributing factors (65%, rate 0.56/10,000 hours)."
   
   
  

 

 

"The most striking observation to be made from Figure 7 is the rate of Jabiru fractures in comparison to both other Jabiru failure mechanisms as well as fractures involving other manufacturers. With a rate of 1.11 per 10,000 flight hours, components in Jabiru engines appear to be fracturing at a rate significantly higher (more than six times) than any other engine manufacturer in the study."

 

"Fractures

 

Occurrence records from the 58 engine failure or malfunctions involving a fractured component from the four major manufacturers were examined to determine what engine components had failed. The distribution of components that failed for each of the manufacturers are shown in Figure 9.

 

For Rotax, Lycoming and Continental engines, no single component has been reported to have fractured in more than two occurrences in the 6-year study period.

 

In contrast, for Jabiru engines, about half (47%) of the all Jabiru fractures reported related to engine through-bolt failures, with 21 through-bolt failures reported between 2009 and 2014.There were an additional two occurrences involving engine studs (see figure 8 for details). The combination of stud and through-bolt fractures accounts for 51 per cent of all fractures. However, for the rest of the analysis in this report, they are counted as separate components.

 

The 21 through-bolt occurrences made up a fifth of all the known Jabiru failure mechanisms and equates to a rate of 0.52 through-bolt failures per 10,000 hours flown. Taking into account the number of aircraft on both the VH and RAAus aircraft registers from this set with Jabiru engines, through-bolt failures occurred in approximately 2 per cent of the Jabiru powered aircraft, or roughly one in 55 aircraft. Given that this analysis relates to the sub-set of engine failure or malfunctions (75%) where the failure mechanism was reported, the actual figure could be higher."

 

 

[Bruce Tuncks]

Good work Mark, I appreciate how you and Oscar have studied the figures. How many of those"fractures" were the result of operational causes?

 

It is easy to design out overheating, you make the heads watercooled. This is done at the expense of weight and cost. Double the cost and you have to live with an import, from the country that produced the Terminator and Hitler.

 

OR you can operate with care.

 

I'm still waiting to know what my risk is, that is a Jabiru engine operated on Avgas and kept below 150 C. So far (13 years ) no problems in the air. ( See how I get around that ground-run incident) . But what if all the Jabiru failures were caused by poor operation which I don't do anymore?

 

 

[Kyle Communications]

I'm still waiting to know what my risk is, that is a Jabiru engine operated on Avgas and kept below 150 C. So far (13 years ) no problems in the air. ( See how I get around that ground-run incident) . But what if all the Jabiru failures were caused by poor operation which I don't do anymore?

Bruce the questions you are asking I doubt whether there would be any compiled or collected data on that. Only anecdotal from some people and Lame's and of course your own experience.

 

I did the above post because maybe there are a lot of people viewing this thread that did not want to spend the time looking at the results and try to sort through them without any sort of bias. I think my opinions are unbiased a fair bit as I have always tried to look at both sides of any argument or situation as it has been a necessity for me in most of my professional life. Oscar on the other hand I am sure is quite one eyed about it and I do not begrudge him that as he is heavily involved with the Jab situation but that also brings with it a lot of running about to validate the argument for the affirmative and I also understand that. Although I think he may beg to differ on that point.

 

 

[facthunter]

Kyle . The reference to fuel was not running out of it but the source of problems with the engine. 912's have a problem with avgas, as the motor doesn't run hot enough for the lead to work right and the Jabiru , by being a hotter running engine would suffer more from deteriorated or low octane fuel, not being safe to use. Mogas wouldn't be suitable for any supercharged aero engine either, especially an aircooled one.

 

In days long past when the Gypsy Major ran bronze heads with no inserts, the motor wouldn't run for long on leaded fuel . The seats would deteriorate very quickly. Just an example of fuel being critical. Stale mixed fuel for two strokes is just as undesirable.Nev

 

 

[Bats]

The difficulty I have with the arguments advanced for Jabiru not being as prone to failure as the figures would suggest, is that the assumptions all run one way. ie if poor operational practice, incorrect fuel choice etc are bringing Jabiru undone at a rate of 1 in 10 over the study period, then how is it that Lycontasaurus and Rotax operators aren't breaking their engines at anything like the same rate?

 

The fact is that the figures in the ATSB report, have confirmed what many pilots had already perceived, that Jabiru engines were failing at a much higher rate than the competition. Disclosure, I started training on a J170 and quite enjoyed it, although the poor ergonomics annoyed me, but I was spooked by a friends (Jabiru) engine failure and hangar talk, and began reconsidering my choice, particularly as the airfield had poor prospects for a forced landing in several directions. Not long after, the school's J170 suffered an engine failure - fortunately away from the field and over an open area, this despite the school being very particular about engine operation, to an extent that I have never witnessed since. I am well aware that one swallow does not a Summer make, but frankly the leaps and contortions of logic offered up by those seeking to dismiss the ATSB report, haven't done anything to dispel my scepticism.

 

 

[Bruce Tuncks]

Thanks Mark and Nev. I am going to continue to believe that the Jabiru engine is quite reliable as long as it is run on good fuel and kept below 150, but it is still a single engined plane and like any other it may lose its power.

 

In any case, the safety feature of all our planes is the low landing speed, not the engine reliability. There was a Jabiru landed in a vineyard at Aldinga, and they walked away. The student had turned the fuel off by mistake at the start of the take-off. The trick is to land between the rows and yes you lose the wings but you just about stop from doing that.

 

Maybe this event is one of those statistics. It was an in-flight engine stoppage for sure.

 

In the meantime, I think CASA should have to show examples of PROPERLY OPERATED Jabiru engines which have failed. This is the whole game as far as I'm concerned.

 

Yes I appreciate the arguments of Bex and others about foolproof things, but I don't have that much sympathy for people who buy an small air-cooled aero engine and then don't treat it with care.

 

 

[Bruce Tuncks]

Hi Bats, I didn't see your posting till after I did mine. Those failures may fit the category I am looking to find out about.

 

Did they both have CHT on all 4 cylinders? Was it a recording CHT set? Was the training Jabiru flown as first solo?

 

What was the cause of the problems?

 

I am willing to concede that the figures are telling a story . What I want to know is whether these figures apply to my operation.

 

 

[facthunter]

The statistics don't really give reasons. I'm not arguing the Jabiru fails less often than a Rotax 4 stroke, but one of the reasons is it's not as critical on the fuel used. There have also been engine failures in GA, where AVTUR was mixed with AVGAS and they don't survive the first take off. A school can be very particular about engine operation in many ways but get their fuel from an unreliable source. Mogas is not a reliable fuel for aviation engines. The distribution process is not controlled enough, plus the product is inferior as far as octane rating is concerned. Nev

 

 

[Bats]

Hi Bruce, I don't pretend to have all the answers - and given the (anecdotally) strange distribution of failures, it is quite possible that the general run of failure modes isn't applicable to your operation. Hope so for your sake. In my case I was flying a school aircraft and had to rely on the hope that everyone else was as meticulous as my instructors were and I certainly tried to be. I was reminded when discussing this with a colleague, that the school had a second engine failure subsequent to my involvement there and has since moved over to Continental and Rotax powered aircraft.

 

Red herring re fuel facthunter, it came from the same tanker that every other piston engine aircraft at Acherfield uses.

 

 

[01rmb]

The Jabiru engine incidents I know of and one of which is referred to by Bats are:

 

• J170 - flight training - engine failure due to incorrect installation of gudgen pin circlip following top end overhaul resulting in piston /valve failure - forced landing in open field
   
   
  
• J170 - flight training - lead fouling of exhaust valves leading to rough engine running - returned to airfield
   
   
  
• J170 - second aircraft with same problem as above on same day and same outcome - flight training - lead fouling of exhaust valves leading to rough engine running - returned to airfield
   
   
  
• J170 - flight training - took off with minimum fuel and with out of balance flight on approach to airfield the engine suffered fuel starvation and forced landing in a sports field
   
   
  

 

 

I believe all the incidents above are recorded in RAA, CASA and probably the ATSB figures (can't be sure because they are not opening the raw figures up for interpretation). Whether they should be considered a 'failure' of the engine, poor maintenance, poor operation or poor fuel choice is how you and the authorities interpret the data and failure information.

 

The 2 'engine failures' above due to lead valve fouling were from the use of Avgas. The two incidents were picked up before a full failure occurred but were recorded with RAA and subsequently CASA and ATSB. The instructor was rightly being cautious and aborted the flight to have the aircraft inspected by the LAME. At the time a large number of other aircraft on the airfield also had lead fouling issues - mainly plugs which needed to be cleaned.

 

Due to the nature of the airfield used, the LAME opinion is that Jabiru engines will run too cool on taxi to and from runway and idling power for holding and landings the engines will build up lead on the head and valves leading to poor sealing and heat dispersal from the valves which will lead to valve failure if the head and valves are not cleaned somewhere in the 400-700 hours range.

 

Mogas will run much cleaner but has a lower octane and is closer to the minimum required to avoid detonation but the fuel needs to be fresh to ensure it has not degraded below the minimum octane level.

 

Each fuel has it's strengths and weaknesses - refer to Jabiru fuel guide. I personally use FRESH 98 mogas as I do not like the effect of lead.

 

 

[Bats]

I'd be very disappointed if #4 above made the list, no engine runs without fuel and that is an issue regularly addressed by CASA and the ATSB. If it is suggested that only Jab accidents from fuel causes are included in the study, then that is where we part company - alfoil headgear isn't a good match for my complexion. As for the lead fouling involving "a large number of aircraft", must say it isn't something I was aware of, despite flying from there on a fairly regular basis over that period, just not in Jabirus any longer.

 

 

[dutchroll]

I would be far more reluctant to fly in a piston twin - I think PA-31s have killed more people due to engine failure in Australia than Jabirus.

I think if you look at the sheer number of flying hours Navajos do, you might get a different picture.

As for feeling safer in a single Jabiru compared to a piston twin? I don't understand the logic there at all, I'm sorry. My M14P is as reliable as engines get. If it has fuel and oil, it just runs. I treat it very kindly but I know of guys who don't, yet still they keep going. I'd still feel safer in a piston twin.

 

 

[Oscar]

The Jabiru engine incidents I know of and one of which is referred to by Bats are:

• J170 - flight training - engine failure due to incorrect installation of gudgen pin circlip following top end overhaul resulting in piston /valve failure - forced landing in open field
   
   
  
• J170 - flight training - lead fouling of exhaust valves leading to rough engine running - returned to airfield
   
   
  
• J170 - second aircraft with same problem as above on same day and same outcome - flight training - lead fouling of exhaust valves leading to rough engine running - returned to airfield
   
   
  
• J170 - flight training - took off with minimum fuel and with out of balance flight on approach to airfield the engine suffered fuel starvation and forced landing in a sports field
   
   
  

 

 

I believe all the incidents above are recorded in RAA, CASA and probably the ATSB figures (can't be sure because they are not opening the raw figures up for interpretation). Whether they should be considered a 'failure' of the engine, poor maintenance, poor operation or poor fuel choice is how you and the authorities interpret the data and failure information.

 

The 2 'engine failures' above due to lead valve fouling were from the use of Avgas. The two incidents were picked up before a full failure occurred but were recorded with RAA and subsequently CASA and ATSB. The instructor was rightly being cautious and aborted the flight to have the aircraft inspected by the LAME. At the time a large number of other aircraft on the airfield also had lead fouling issues - mainly plugs which needed to be cleaned.

 

Due to the nature of the airfield used, the LAME opinion is that Jabiru engines will run too cool on taxi to and from runway and idling power for holding and landings the engines will build up lead on the head and valves leading to poor sealing and heat dispersal from the valves which will lead to valve failure if the head and valves are not cleaned somewhere in the 400-700 hours range.

 

Mogas will run much cleaner but has a lower octane and is closer to the minimum required to avoid detonation but the fuel needs to be fresh to ensure it has not degraded below the minimum octane level.

 

Each fuel has it's strengths and weaknesses - refer to Jabiru fuel guide. I personally use FRESH 98 mogas as I do not like the effect of lead.

If #2 and #3 happened on 13/01/14, then they and #4 are most certainly on the CASA spreadsheet that they used to support the implementation of the Instrument. In the CASA spreadsheet, #2 and #3 are noted that - in both cases - ground running could not reproduce the problem.

 

 

[01rmb]

Oscar - that is them.

 

The first which happened in 2013 which whilst considered an engine failure came about as the result of incorrect maintenance.

 

The only problem found with #2 and #3 was the lead fouling of the heads and valves. Switching to mogas resolved the problem - well except for #4 of course...

 

The other aircraft affected across the airfield (a number of Cessna 172s etc.) had fouling issues so not just limited to Jabirus although my own also suffered from the fouling issues. Most of the aircraft just suffered from poor starting, black smoke and less than optimum performance.

 

 

[Oscar]

Well, thanks for clearing that up, 01. If there was an outbreak of lead fouling across the airfield, was there any action taken to investigate the fuel batch? Avgas is USUALLY very reliable for quality - though the infamous problems of an earlier time caused at the very least, 100s of $k in costs to sort out, so it's not infallible.

 

#4 was an obvious nogas problem..... but is listed in the CASA spreadsheet as an 'engine failure or malfunction'. In the comments section, it is noted that 'Maintenance records requested and ATSB formal report and RA-Aus report also requested.'

 

One would have thought that with all of that information available, CASA MIGHT have revised the inclusion of that incident as 'engine failure or malfunction' - but they didn't, quite obviously. And Senator O'Sullivan has them ON TOAST for that - because they stated, in Senate estimates, that an 'out of fuel' incident would NOT have been included, and it is right there, in print...