ATSB report into light aircraft engine failures

[facthunter]

Perhaps less of them should fly, or don't saddle the rest with "their" problems. To the free marketists the problem will solve itself. No one will buy, if it's no use to anyone. Nev

 

 

[piecrust]

They are of high failure rate that's what the stats tell you. Simple and clear. No more debate or discussion.

 

 

[Sloper]

Goodaye all

 

There seems to me there are statistics, facts and opinions mixed up in this.

 

Facts would require engine failures against hours flown on all types GA and RAA

 

With clear causes.

 

Statistics are a tool to interpret facts, these can be skewed by bad and incomplete data.

 

So can sometimes be useless.

 

Opinions are formed both by hard facts and bad data, its is a indervidual's own perception of the data.

 

Right or wrong its the inderviduals choice.

 

l have a opinion on engines and base my choices on that, would like to see clear data either to reinforce my opinion or correct my mistake.

 

One piece of information l would like to see is engine cost against failures?

 

Cost does drive the choice of a engine.

 

You get what you pay for, but thats only my opinion.

 

regards Bruce

 

 

[BLA82]

two points:If you read the report (and your post) R912s ARE killing people while Jabs (though failing at an unacceptable rate) are not ...

Your post and yout singature tag line are in conflict ... Jab pilots are doing the Woo Hoo what a ride yet your post is against that ...

 

Just saying

Jasper if you class signature lines with that much importance maybe look into the history of my signature and then form the opinion.

 

 

[Keenaviator]

Very few have said there wasnt a problem but many have said CASA action is not detailed and unjustified. If fed from this report its no surprise as it too doesnt differentiate models of engines either. Ill bet that amongst some shoddy info on the problems, the size of the engine (both makers) IS known.This report doesnt breakdown engine type or even seriousness of problem

No doubt throughbolts are an issue, the upgraded 7/16 with o rings is a full tear down to fit Id expect. Hoping for owners this isnt whats required to release limitations.

 

The concept that resonance is involved.....maybe but surely that makes the data applicable to engine cylinder configuration

 

What the report does indicate is what a bad year of problems can do to a small data set. The previous >2013 report draft indicated failure rates the same for both manufacturers.

 

With some stretching it also might indicate something introduced into Jab engines around 2007/08 has brought in significant issues - any guesses?

Big heavy hydraulic lifters.

 

 

[jetjr]

Bex, i see this as an issue with report, it doesnt say Jab fail more than air cooled rotax, just that the brand fails more than Rotax brand

 

The results could be much worse for 2strokes, as to be expcted, and better for others.

 

Comparing by maker is nonsense the more I think about it. Trying to compare a old 2 stroke with 2015 lycoming or Jabiru.

 

They should have access to engine model and serial number on all failures

 

Jabiru have issued a response outlining isues with the report, before it was released, otlining errors. They claim fuel exhaustion and rough runnong events still in the data

 

 

[Nobody]

Jetjr,

 

The difficulty with comparing by serial number/model is that it may not necessarily represent the full state of the engine. Jabiru have issued changes to throughbolts and lifters and these may have been applied to engines in the field. The other thing is that there are potentially some configurations that do not have a large number of samples out in the field. Comparing by manufacturer isnt perfect but I can understand why the ATSB have done that.

 

 

[kasper]

Jetjr,The difficulty with comparing by serial number/model is that it may not necessarily represent the full state of the engine. Jabiru have issued changes to throughbolts and lifters and these may have been applied to engines in the field. The other thing is that there are potentially some configurations that do not have a large number of samples out in the field. Comparing by manufacturer isnt perfect but I can understand why the ATSB have done that.

Whilst in general I agree the fact that there is no differentiation between the 4 and 6 cyl engines is very clearly problematic when looking at mechanical failures (through bolts) that are likely to be related to vibrations.

The issue with the CASA instrument is that its the equivalent of bundling all rotax 9__ series engines into one bucket ... or all rotax 5__ engines into one bucket.

 

Illogical and really unfair to both the manufacturer and owners.

 

 

[turboplanner]

If you look through the RAA reports, it becomes clear that what they receive, quite often is little better than a short anecdote without the necessary nomenclature, so it looks to me like the cleanup has to occur down at that level, which will lead to more squawks about persecution.

 

 

[jetjr]

K - Its the same as putting all Rotax into one bucket. Not reasonable

 

TP - your correct, older info is slim and selective. Im not sure how with such limited info, its accuracy could be vouched for. It seems most damaging info is from 2014 when things might have improved record wise.

 

I agree its not perfect to broadly breakdown by types, but would illustrate better where problems lie. They could easily differentiate 2200 and 3300 and solid vs hydraulic lifter or 9 series and 5 series for example.

 

By making sample groups smaller also brings in statistical problems meaning no confidence in conclusions. I expect it would make a selection of engines look worse. But would perhaps not be as damaging to an entire brand.

 

Statistically the data isnt very solid with small sample numbers and subsequent high variation present year to year. Let alone doubts over base info accuracy. But its all thats available.

 

Its unusual NOT to see key point of a damaging report further evaluated and broken down further.

 

Remember they - CASA - have reacted on this data, not just proposed as academic exercise to inform people or used as direction to improve data set. All Jabiru engines are limited.

 

Then its back to the debate, what if Jabiru disappear or loose interest? Thousand or so aircraft still flying with no solution. Is that a good safety outcome?

 

If it were noted that say problems were largely with hydraulic lifter 4 cyl, or perhaps throughbolts on 6 cyl and valve problems on 4 cyl a totally different action and investigation could be undertaken

 

Linking all Rotax together is equally flawed maybe more so.

 

The report and Jabiru make the comment there's no indication of the compliance of engines to SB and its true, we know of several with broken old throughbolts problems after mandatory replacement period had ended.

 

That IS a tough thing to evaluate with self maintenance and maybe crook records or butt covering common.

 

Read both the draft and then this report, very different language and message being provided. Not sure why. It would be interesting what numbers say now 2015 is over and results seen.

 

 

[JEM]

To get some perspective in the ATSB report suggest reading the Jabiru reply.

 

 

[Nobody]

JEM,

 

Do you have a link to the Jabiru response? I cant see anything on their website under news.

 

 

[Bruce Tuncks]

Where are the Volkswagen derivative engines? Were they left out because they have such a bad record that Jabiru would look good? The only write-off I have ever seen at Gawler was a Volkswagen aero conversion which failed on its first flight.

 

And Bex, I appreciate your argument about things need to be foolproof on account of there being so many fools, but I don't want to pay more for this feature, or carry extra weight. Aircraft are fundamentally not fool-proof things.

 

Furthermore, I don't trust any government agency to tell me the truth, especially with figures they have processed in some way. Where is the raw data? Are they making it all available?

 

 

[fly_tornado]

Bruce, are you saying that the ATSB purposely left VW engines out so that the case against Jabiru was solid?

 

 

[Nobody]

They didnt completely leave out the VW engines. They are there in figure 2 with 4 reported failures for "Volkswagen" and 2 for "Revmaster". They did make the point that failures by engines other than the major 4 makers(Jabiru, Rotax, Lycoming and Continential) only represent about 6% of the failures and so wernt included in the detailed analysis.

 

 

[gandalph]

JEM,Do you have a link to the Jabiru response? I cant see anything on their website under news.

Here it is Nobody, and anybody else for that matter....

 

Hello Jabiru Fleet,

 

We believe that the ATSB are today releasing their report on “Engine Failures and Malfunctions in Light Aeroplanes”

 

It would appear that CASA may have been waiting on this report to be released before they are prepared to make changes to the limitations imposed on Jabiru powered aircraft.

 

We were provided with a copy of this final report prior to release (on 02/03/2016) for comment. We provided feedback highlighting the inaccuracies of data used by the ATSB to form their conclusions however it appears the report may have been already printed and will be released.

 

With a view to providing you, our owners and operators, updates and communication on the scope of works being done around the lifting of the limitations, below are extracts from the correspondence sent highlighting inaccuracies and the ATSB responses.

 

We are as always, determined and committed to the advancement of safe, affordable recreational aviation in Australia and to the health of the Jabiru fleet.

 

Despite the many setbacks faced, Jabiru, and the spirit on which it was founded lives on!

 

Happy Landings

 

From the Team at Jabiru

 

We have received the latest version of the report AO-2013-107 and letter of the 2/3/2016 and raise the following points in response. It is very important that these are reviewed prior to release of the Final report.

 

6. Higher risk engine failures 1

 

Jabiru comments:

 

An engine failure in a single-engine aeroplane can have a variety of safety consequences depending on the extent of the failure, phase of flight, pilot response and availability of suitable landing areas and the inherent safety features of the aircraft structure and performance at stall speed. (Structural safety features provide defences that stand between the occurrence and the outcome (ARMS) eg. Jabiru flight controls are positioned so as not to contact the torso in an accident, there is also head clearance, sacrificial undercarriage and above ASTM standard reserve factors for the composite structure.)

 

ATSB response: Noted

 

ATSB action: Change to report

 

ATSB comments:

 

The ATSB applies the event risk classification (ERC) to all 7,000 occurrences entered into the database each year. This is achieved through detailed rule-based process that depends on the circumstances to the occurrence and size and type of aircraft. However, it is impractical to consider the safety features of the airframe for every make and model of aircraft involved in occurrences reported to the ATSB beyond protection provided by an aeroplane compared to aircraft such as microlight trikes. In addition, the application of such rules would require referencing empirical crash worthiness findings for all aircraft makes and models. Similarly, it is impractical to establish the aircraft performance at stall speed for every make and model of aircraft involved in occurrences reported to the ATSB.

 

Text has been added to the report as a footnote to note that the ATSB ERC ratings do not take these two things into account.

 

Jabiru comments:

 

By not including crashworthiness in the risk assessment, ATSB is biasing the report against Jabiru and not including a crucial part of the ARMS methodology upon which it is relying for the safety argument. (Stall speeds and MTOW are not difficult to find for the aircraft makes and models and fatality statistics are readily obtained from the ATSB database search facility.)

 

Also it should be noted that Jabiru aircraft have been certified to BCARS Section S airworthiness standard which requires at S 143 a) The aeroplane must be safely controllable and manoeuvrable during; 6) sudden engine failure.

 

Jabiru suggests, if it is too difficult to include quantitative crash-worthiness data for the aircraft, then, at the very least, an additional note be included in the report which gives the fatality statistics, indicating that in the 18 serious incidents listed, there were three fatal accidents, none of which involved JABIRU aircraft, even though JABIRU did have three occurrences.

 

5. Comparable engines

 

Jabiru comments:

 

The use of the words “comparable engines” is very misleading. Jabiru, Rotax, Lycoming, Continental etc. are very different in weight, size, cost, performance and certification levels. The LSA category allows engine certification levels with significant endurance differences as an example. A note to this effect should be added.

 

ATSB response: Not accepted

 

ATSB action: No action required

 

ATSB comments:

 

The Jabiru 2200 is 2.2lt capacity, 62.8kg and produces 80hp and the 3300 is 3.3lt, 83.5kg and 120hp. The most common Continental engine in the study is the O-200 which is 3.29lt, 77.2kg and produces 90 -

 

Page 6 of 13

 

100hp. The most common Lycoming engine is the O-235 which is 3.823lt, 108.9kg and produces 100 – 135hp. Whereas the most common Rotax, the 912, is 1.21lt, 60lt and 80hp. Comparing these engines puts the Jabiru engines in the middle for capacity, weight and power output. Additionally, all these engines are internal combustion piston engines, four stoke, and air cooled (except the liquid cooled cylinder heads on the 912) with horizontally opposed cylinders. The ATSB therefore disagree with the statement that our comparison is ‘very misleading’ and that these engines are ‘very different’. The comment about the endurance applies to all engines in the LSA category and does not bias Jabiru any more than Rotax.

 

Jabiru comments:

 

It should be noted that comparing the reliability of engines that have been designed to the higher FAR33 (CAR13) airworthiness standard (used in Normal Category aircraft) to engines that has been designed to JAR-22H is extremely biased. These 2 standards are significantly different in requirements for endurance and to be fair, this fact should be noted in the Final report. (The different design standards specify varying compliance requirements, and rigor to which compliance must be demonstrated. The different designs standards are one method the NAA uses to identify and manage differing levels of safety between different classes of aircraft. A FAR 33 (CAR13) engine, for instance, is eligible to be fitted to a transport category aircraft where as a JAR 22H engine is only eligible to be fitted to a two seat recreational aircraft.)

 

Furthermore, to make a comparison between the reliability of different engine manufacturers and then use this information to draw safety recommendations, even if these are "comparable engines", is inappropriate as there is no grounding of the results against the design standard requirements. JABIRU notes an EASA comment, made in 2011 "Annual Safety Recommendations Review" which reads

 

"Certification Specifications ( standards) CS 23 for normal, Utility, Aerobatic and Commuter Aeroplanes, and CS-E for Engines, do not take a probabilistic approach to piston engine failure. Reference to minor or major severity classifications to piston engine failures are therefore inappropriate for this class of aircraft. ( Remember that this is a higher class of aircraft than the sport and recreational aircraft that have been considered in the ASTB report) For piston engines, CS-E-210 requires that a failure analysis be performed to establish that no single fault could lead to unsafe engine conditions beyond the normal control of the flight crew. While no specific reliability target is given, state-of-art engines typically achieve loss of power rates of between 10-3 and 10-5/flight hour. Aircraft are certificated on the basis of assured continued safe flight or landing following engine failure. in effect CS-23 mitigates the consequence of engine failure, for instance by controlling stall speed, and structural crashworthiness for single engine aircraft, or by requiring investigation of handling qualities and performance of multiple engine aeroplanes with a failure engine. However, it cannot be excluded that, under some conditions, the effect of engine partial or complete loss of power at aircraft level remain more severe than minor or even major, but the overall safety objective can still be met considering the reduced exposure time to such conditions. While the Agency will continue to monitor accident/incident trends, and related causal factors, there is currently no safety/economic data to support changing airworthiness standard in order to increase piston engine reliability."

 

Now given that engine failures are occurring, an evaluation of the types of aircraft level incidents/accidents which follow these loss of power events, draws questions on respect to whether the aircraft design does meet the aircraft design standards for "continued safe flight and landing following a power loss", and on the airman-ship which is involved, i.e. loss of control on approach, being an indication of aircraft handling problems, to name just a few. Is the ATSB proposing to address this with a follow investigation into the causal factors relating to fatal accidents?

 

The two reported failures of studs (data not shown in Figure 10) were reported

 

at 1,183 and 438 hours in service. Jabiru overhaul manuals currently require a top end overhaul

 

after 1,000 hours and a full overhaul after 2,000 hours, with the engine through-bolts and studs

 

being replaced at both overhauls. It can be seen from Figure 10, however, that most of the failed

 

through-bolts (19 of 21) did not make it to the 1,000-hour mark.12 Furthermore, seven throughbolts

 

(and one stud) failed before 500 hours.

 

Jabiru Comment: Jabiru Engine Life Limitations are based on "engine time", which is the time between engine start and engine shut down, not "Flight Time". JABIRU is aware that it has been common practice to schedule engine maintenance against "flight time" this is particularly the case for the 2009-2014 period where most flight training operations were recording flight time instead of engine time. With this in mind, those failures between 800 - 1000 hrs are likely to be at least equal to but more probably greater that 1000 hour engines. Refer JSL010-1 Nov 2014. This needs to be noted in the Final report.

 

In the set of 21 through-bolt failures reported to the ASTB between 2009 and 2014 the following

 

operation types were represented:

 

• Flight training – 10 occurrences

 

• Private – 5 occurrences

 

• Unknown – 6 occurrences.

 

Not including the unknown operation types, five of the through-bolt failures occurred in aircraft not

 

involved in flight training. Engine hours data is known for four of the five. For these four aircraft the

 

total engine hours before the through-bolt failures were 675.8, 1,600, 390.8 and 782.5.

 

Jabiru Comment : Factually INCORRECT

 

There are NO through bolt occurrences listed for 2009 -2014 that were aircraft engines that had not been used in a flight training facility.

 

These eleven references below involved aircraft used for flight training and have not been recorded/reported as flight training occurrences in the ATSB supplied spreadsheet.

 

ATSB reference 201000248

 

ATSB reference 201004434

 

ATSB reference 201004666

 

ATSB reference 201004699

 

ATSB reference 201008980

 

ATSB reference 201106841

 

ATSB reference 201107115

 

ATSB reference 201300563

 

ATSB reference 201403744

 

ATSB reference 201403769

 

ATSB reference 201403775

 

20. Through-bolt fracture analyses

 

Jabiru comments:

 

The drawing of conclusions based purely of statistical analysis without an in-depth knowledge of the timing of the application of the Jabiru Through bolt Service Bulletins by the individual operators is dangerous. This is a very complex analysis and requires consideration of the many factors including the experience of the installer of the through bolts and the variability of the application of Loctite for the earlier Service Bulletins. Without study of log books and a depth of knowledge of the through bolt configurations that evolved, incorrect conclusions have been drawn in these 2 pages. These 2 pages need to either be deleted or rewritten after consultation with Jabiru. Jabiru has thorough research into Page 11 of 13

 

through bolt failures which must be understood by technical persons in ASTB before this document is made publicly available.

 

ATSB response: Partially accepted

 

ATSB action: Change to report

 

ATSB comments:

 

The scope of this ATSB research investigation was to determine whether there were any issues related to the reliability of light aircraft engines. The investigation report has achieved this aim, establishing that through-bolt fractures and valve train failures have been occurring at a disproportionate rate on Jabiru engines relative to other engine manufacturers. The information on pages 19 and 20 is factually correct. The Jabiru response does not offer any evidence or reason as to why it is not factually correct.

 

As part of their Draft Report response Jabiru have supplied an engineering report (dated 19 November 2015, after the ATSB draft report was received) which examines the cause of through bolt failures. The results of report have now been documented in the Final ATSB report.

 

Jabiru comments:

 

See above list of flight training school aircraft misreported/misclassified.

 

25. Occurrence check

 

Jabiru comments:

 

Jabiru is now in the process of checking the list of 134 engine related occurrences. Please note that only since June 2012, has the ATSB supplied Jabiru with ICAO Annex 13 Chapter 4 Accident and Serious Incident Notifications. 45 notifications from the earlier period covered by the report, starting at 2009, have recently been requested by Jabiru to assist with the verification of the occurrences. These have been received. To date Jabiru has not been given any notification from ASTB of the 58 occurrences categorised as incidents. Any assistance with details of these occurrences that can assist with tractability, will aid the verification of the statistics presented in AR-2013-107. These are 12 occurrences that should be checked and the statistics adjusted accordingly

 

ATSB response: Partially accepted

 

ATSB action: Change to report

 

ATSB comments:

 

The ATSB reviewed all of Jabiru comments in the Excel spreadsheet of data provided by the ATSB. Adjustments were made where appropriate. In particular, some duplicate occurrences were removed. However, some suggested duplicates were confirmed to be separate occurrences. Anything that resulted in an inflight engine failure or malfunction (apart from fuel exhaustion or starvation) remains coded as an engine failure or malfunction as per the ATSB coding practices. The reasons why the engine failures were (if they were not already) coded as safety factors in the ATSB database. Other safety factor information provided by Jabiru were used to updates some records where appropriate.

 

In addition, Jabiru supplied further amendments to the data in the Excel spreadsheet on 17 February 2016. The ATSB has assessed these additional changes in the same way as above and made changes where appropriate.

 

All of the data presented in the Final report has been updated following a repeated data analysis after the ATSB database records were updated.

 

Jabiru comments:

 

The ATSB figures still include a fuel exhaustion occurrence for Jabiru.

 

At Page 1

 

· a rough running engine (coughing, spluttering, etc)

 

Jabiru Comment: Should be expanded to include - which may be caused by an internal engine problem or alternatively caused either by external influences like carburettor icing, bird strike, all propeller issues, fuel contamination, dirty spark plugs, insects in the carburettor intake, or by unapproved methods of operation, part modifications and poor maintenance which is outside of the control of the Engine manufacturer.

 

These factors which the public do not associate with engine malfunction have been mainly disguised in the report with no mention until page 13.

 

Maintenance issues contribute significantly to many of the occurrences yet have largely been obscured by the classification and reporting system that bases the report.

 

 

[gandalph]

Bruce, are you saying that the ATSB purposely left VW engines out so that the case against Jabiru was solid?

Oh FT! The moon will be up soon. Shouldn't you be taking your medications and closing the lid?

 

 

[fly_tornado]

Gandalf, take your old man pills, its looking like someone in the ATSB is conspiring against the patriots. This is huge I look forward to more details.

 

 

[Ron5335]

Before we get too oopee doopee with each other.

 

Check out the ATSB 10 year snap shot report

 

Taken from the last paragraph regarding Non VH aviation reporting more .

 

"In 2014, 99 accidents were reported, nine of which were fatal and another eight leading to serious injuries. Most accidents involved aeroplanes, as these are the most common recreational aircraft."

 

Who writes their material !!!!!!!!!

 

 

[turboplanner]

If you check the CASA Self-Administration bodies you'll find balloons, and gliders, and hovercraft could be considered aircraft.

 

 

[Nobody]

Before we get too oopee doopee with each other.Check out the ATSB 10 year snap shot report

 

Taken from the last paragraph regarding Non VH aviation reporting more .

 

"In 2014, 99 accidents were reported, nine of which were fatal and another eight leading to serious injuries. Most accidents involved aeroplanes, as these are the most common recreational aircraft."

 

Who writes their material !!!!!!!!!

As opposed to helicopters, gyroplanes and gliders.

 

 

[Bruce Tuncks]

Bruce, are you saying that the ATSB purposely left VW engines out so that the case against Jabiru was solid?

Yes I am saying just that.

You have to take into account the fact that all this lot purposely force aircraft like mine to fly lower than a safe height over high ground while there is completely unused controlled airspace just above us. So of course they can't be trusted.

 

 

[fly_tornado]

Bruce, so where are these crashed and now missing VW powered aircraft and their dead pilots? this is sounding like an X-File

 

 

[BLA82]

If only Jabiru put as much effort in fixing their product as they did in trying to cover their backsides in that letter they might be better off.

 

 

[turboplanner]

Where are the Volkswagen derivative engines? Were they left out because they have such a bad record that Jabiru would look good? The only write-off I have ever seen at Gawler was a Volkswagen aero conversion which failed on its first flight.And Bex, I appreciate your argument about things need to be foolproof on account of there being so many fools, but I don't want to pay more for this feature, or carry extra weight. Aircraft are fundamentally not fool-proof things.

Furthermore, I don't trust any government agency to tell me the truth, especially with figures they have processed in some way. Where is the raw data? Are they making it all available?

The 4 VW are listed on Page 6 Bruce along with the 6 Subaru, and a series of engines with 1 failure.