Jabiru engine failures

[Squawk7700]

Take it easy with the insults chaps, there's enough mis-guided nut-job forum-trolling failed political candidates on other forums, we don't need them coming here to get their jollies too

[Creampuff]

How may days this year have you spent in a maintence shop.

How many services have you done this year or ever

How many Ad eng 4 have your carried out.

How many engine changes have you done

How many cylinder changes have you done.

How many fcu changes and set ups have you done.

How many mag changes have you done.

How many engines have you released

I love it when he's goaded into dropping the dyslexia schtick!

Solid gold.

[gerry111]

That was quite readable, for a change. Now we need to work on his punctuation.

[rnuts]

Keyboard warriors pathetic !!

[Hempy]

yr rihgt,

- how many return customers do you get? How many have a choice?

- is it easier to get away with releasing an engine when no one can understand what you've written on the MR?

- how many hours this year have you spent over-billing people?

- how many burnt clys on the hangar floor come out of aircraft you regularly maintain?

edit: rnuts you had to be there..

[Ex FSO GRIFFO]

Hi Mr SQ,
I opened this particular email for the first time today... At 11.31 or whatever it was. Congrats for you getting it last Monday.......

I thought it may be 'of interest' to Jabiru drivers.

Cheers

[Squawk7700]

All good exfso, though you were alerting us to yet another amendment. Glad it wasn't one.

[yr right]

So Clinton I would assume the following

How may days this year have you spent in a maintence shop.
One hour to drop aircraft off one to pick it up.

How many services have you done this year or ever
Zero
How many Ad eng 4 have your carried out.
Zero
How many engine changes have you done
Zero
How many cylinder changes have you done.
Zero
How many fcu changes and set ups have you done.
Zero
How many mag changes have you done.
Zero
How many engines have you released
Zero


So that make you an expert.

Humpy dumpty

We'll actually we would have near 100 percent return rate in fact we picking up a lot of work. And as for lame over charging we'll not sure lame do the billing Any way please feel free to bring your aircraft here and we look after to you. I'll make sure you get the special treatment you deserve.

[yr right]

And as for flat earth that's easy to fix.

Do what every other aviation course product aircraft has to do before it can be used.
Get it approved.

[Wunwing]

I've been watching this thread and many other on ROP/LOP for some time and I'm becoming more incredulous by every post on the subject.

My background is 20,000 hours + operations on jets,some time on big pistons and I have been a LAME (both airline and GA) although not engine endorsed.

What I find so concerning is for the most part I have worked under a rigid set of rules and procedures which self evidently worked well. Possibly this was because our beloved regulator had very little say in them or possibly because everyone knew what they were doing.Whatever there was a clear understanding, internationally and locally of how things worked and why.

What I'm seeing here is thread after thread of everything from hard facts to "witch doctor" stuff. We've had piston engines since Orville and Wibur etc and we still dont seem to agree on how they work?Its hard to recognise this as part of the same industry that I was familar with. Thinking about it its part of the reason that after a lifetime in an industry that I loved to be part of, I walked away from it totally.

Getting back to the thread, I hope that Jabaru get things sorted but if this thread is anything to judge where things are at ,I wouldn't hold out too much hope.

Wunwing

[Jabawocky]

Now onto the Jaba engine.

It is a Lycoming IO540…..thanks for asking, 1100 hours of which 10% (climbs) are Rich mixture ops to a target EGT, and the 90% remaining are LOP cruise and descent.

If you are referring to JABIRU engines, perhaps call them that, it might save the confusion.

I notice that you have once again not answered my question from two days and pages back, ignored Creamie and started on a tirade of garbage in response.

And seeing you are so smart please explain to me what an approved course is and how one would actually approve something to which there is no approval criteria to meet in the first place.

And which parts of a POH are approved as part of the FAA certification?
How many engineering degree/associate degree/diploma/ or tertiary studies have you done?
How many FAA certification projects have you done or participated in?
How much detonation testing have you done or participated in?

Answer some of the questions in the past with your best efforts and when I get some time in the next few days I will answer some of your questions of the last day or two. In particular the cause of burned valves. This is one of the biggest Old Wives tales areas of all time.

[Jabawocky]

Wunwing,

The 20,000 hours of jet time you have participated in has been a tiny part of the problem. The invention of the jet engine and the jet age. All the knowledgable folk, engineering effort and focus was shifted from piston to jet. As a result 50 years ago the trouble started.

There is no Witch Dr stuff in the science of combustion, it has been well known and documented since pre WWII and the basis for much of the APS class that "yr right" seems to fear so much. In fact that knowledge base got lost with the advent of the jet.

The fact that the guys back 50 years ago had it right, and with modern data collection and development by a small few in the last 15 -20 years simply proves they had it right back then, speaks volumes.

The facts are the fuel burns the same today as it did in the 40's and before, the cylinders know no different either. What happened was lots of technically unsound stuff crept in and folklore was made. Most of which created a big drift between knowledge that was correct and that which was misguided. The cause of this was not understanding the difference between correlation and causation.

hope that helps.

[Aussie Bob]

MAYBE it has been shown that you can't damage a Continental/Lycoming by being too lean. Even if true I don't believe that applies to all engines.

Some few pages back Andrew wrote the above. In part he is correct, here is my experience of running an O360

First you need an engine monitor that provides data on all cylinders and measures fuel flow, you then observe the following:

Lean till she runs rough then enrichen slightly for smoothness as per the Lycoming book and you quickly realise that at this point some cylinders are lean of peak and some are rich of, or at peak EGT. Then discover that small changes in throttle setting and RPM will result in changing CHT's without touching the mixture at all. Adding more fuel via the mixture has very little effect on CHT. If you want "fuel" cooling you quickly discover that it is only achieved by very high (way above the manufacturer's data) fuel burn.

Play a bit more and you discover that there are settings where all cylinders are pretty well even and LOP operations are possible. On my engine it is number three cylinder that gets the hottest. It is far faster and easier to cool this cylinder by leaning the mixture more till this cylinder is LOP. If there is a lean "stumble" a bit of carby heat can be applied. For long distance cruising I find 26" MAP and 2450 - 2550 RPMs with a fuel flow of around 31 litres per hour gives me about 60% power with all cylinders under 350 F. You could not do this without the monitor.

Andrew states that this is not possible with all engines and he is correct, without the engine monitor it is not achievable and if the engine has a big gap between where the first cylinder peaks and the last cylinder peaks that will also make it impossible but these gaps can (most likely) be rectified.

If I owned a Jabiru (heaven forbid), the very first thing I would fit would be an engine monitor followed by water cooled heads. Next would be a throttle body injection unit so I could adjust the mixture inflight. Without engine monitoring and CHT correction where needed I think the Jabby failure rate will remain constant.

Without the proprietors attitude changing I can also see Jabiru failing. Our school had a through bolt failure at 300 hours. We were told it was "lack of maintenance". No warranty but a tiny bit of help on a new engine. Pure BS.

I still think the machined crankcase is also to blame. Where in the world is anyone else doing this? It is nothing but a cheap alternative to casting with the correct metal. If it was any good then everyone would be doing it.

[Andy_RR]

Originally Posted by Aussie Bob

I still think the machined crankcase is also to blame. Where in the world is anyone else doing this? It is nothing but a cheap alternative to casting with the correct metal. If it was any good then everyone would be doing it.

The fully-machined billet aluminium block is a red herring, Bob. If the material is selected correctly and the design is good, it should be much more consistent than a casting which can be notoriously difficult to control quality on.

There are lots of people in the world making billet blocks for high performance/race engines.

I think ULpower are another company using billet blocks for the LSA market. It's a great way to achieve low volume, high quality parts. Bear in mind that a large proportion of military airframes are machine from solid too.

[Mach E Avelli]

Aussie Bob's description of running LOP is nicely put. The flight engineers of olden days did much the same thing with the big radials. Only difference being they had 28 or multiples of 28 cylinders to fiddle with, so it was a full time task.
Unfortunately all this is totally academic for the standard Jabiru setup, where the pilot has no control over mixture in flight.
Other than expensive modifications (and until we have an outcome from CASA I for one won't be spending a cent on my aircraft) all that can be done in the short term is to keep a careful watch on compressions and pull the plugs every 25 hours. It is said that plug colour is meaningless if running on PULP but I reckon if three were uniformly black and one was a lighter shade of grey, it would indicate something irregular.
Other more knowledgeable folk invited to comment.

[yr right]

Creamie or Clinton which is one in the same. You already admitted that before. Or do you use creamie as your ultra ego. Maybe you may require some sort of medical help not from the cruch of Scientology but cause they don't believe in that sort if stuff.

[Jabawocky]

Steve, when are you going to answer some serious questions in some attempt to actually learn something, from someone who is actually willing to help.

Willing, but patience running out.

[Jabawocky]

This was emailed to me today. Worthy of a read.

To Whom it May Concern,
The basis of the meeting with CASA was in essence to say that our engine
incident rate was higher than Rotax based on flying hours and this was the sole
basis for punitive action.
CASA refused to recognise our overall safety in regard to fatalities and serious
injury where we have an outstanding record. We tabled statistics from the United
States which showed us to be the safest LSA aircraft in the United States. This
was disregarded. You may see these statistics at the following link.
http://flightdesign.com/files/Media/...20Consumer%20-
%20LSA%20Accidents.pdf= Similar statistics don’t seem to be collected in
Australia or they are being withheld.
CASA stated that they had not researched the engine failure rates in any details to
ascertain if the failures were the result of operational, maintenance, or design
related factors. They did not release to Jabiru the actual statistics they had on
hand of engine failure rates. There is no international standard for the reliability of
piston aero engines and to compare one manufacturer with another is without
precedent. CASA also stated that there had been a spike in the incident rates on
Jabiru engines. This statement was refuted by the RAA who had on hand data
that showed there was no spike and this was tabled at the meeting. The fact that
CASA states that Rotax statistics are better than Jabiru statistics is not a point of
law and cannot be enforced under law.
Our own research indicates two failure modes, through bolt failures and valve train
failures which are the major contributors to the statistics. Our research and
statistics also reflected that the majority of these failures occurred in hard working
flying schools using 2200 engines. Engines used for private applications have
virtually no through bolt failures on our records. Our latest research and statistics
tell us that the introduction of roller cams has to date eliminated valve train failures
and the introduction of 7/16 through bolts in production engines has to date
eliminated through bolt failures. We have also introduced valve relief pistons which
do not allow a stuck valve to impact the piston. These pistons are now standard
and have been used on all overhauls and repairs since August 2013 and were
introduced to production in October 2013. We are also upgrading engines to the
current spec at owners request at major service intervals such as top end
overhaul. CASA were intently interested in our analysis and research which
justified the introduction of the latest modifications. To this end they have agreed
to come to Bundaberg and review our engineering development. We welcome this
move.
The problem is getting smaller by the day. It should be put in to perspective that
the incident rate quoted by the RAA has been 0.03% in some 90,000 movements
of Jabiru Aircraft which is a very low number and translates to 1 in 3,300 take offs.
Our own research and statistics establish that if we eliminate through bolt and
valve train failures the statistics may very well be more favourable than Rotax.
Our engineering efforts over the last three years have been to address
predominately these two failure modes that developed after years in the field.
Several Service Bulletins have been issued however we have no way of knowing
the take up rate of these Service Bulletins.
We are in the process of implementing contacting every flying school to ascertain
the configuration status of each Jabiru engine they operate. We will then suggest
individually a preventative program.

[Aussie Bob]

Thanks for the link and info Andy, my comments are from reading other info which could well be wrong but also from my own experience as an hobby machinist where external dimensions of billet alluminium can change when internal material is removed which of course can be fixed or allowed for. The milled from billet crankcase also looks really neat. A Jabby engine is a great display to show "interested in aviation" folk.

Another story I have heard is that the UL engine came about by someone producing a Jabby engine and asking for something better. The first thing they did was cast the crankcase. Perhaps just a story. This industry is full of them.

[Squawk7700]

Copying things doesn't always work eh!

Have been watching someone replace a head gasket on a Ssanyong, made under licence from Merc. Ouch !

Will be interesting to see how the UL pans out.