Two more Jabirus down

[onetrack]

It appears that the Jabiru curse has struck again, Two more Jabirus down in Queensland within 4 days. It's lucky they make a good crashworthy frame! - they need it, with the regularity of those engine failures!
What was it Jack Ranga said in another thread? - "If you want a Jabiru, just buy a paddock, there's a Jabiru engine in most paddocks!" :)

Plane makes emergency landing in Victoria Point paddock (http://www.brisbanetimes.com.au/queensland/plane-makes-emergency-landing-in-victoria-point-paddock-20130820-2s8em.html)

Pilot uninjured in emergency landing at Parkinson (http://www.brisbanetimes.com.au/queensland/pilot-uninjured-in-emergency-landing-at-parkinson-20130816-2s22r.html)

[717tech]

Not convinced that second one made it to the paddock the article says they landed on.

[falconx]

Pigs were never meant to fly

[onetrack]

717tech - I'd hazard a WAG that the second Jabiru landed in a paddock with trees at the far end of it! If he'd landed fully in that solidly-wooded country behind the aircraft, that Jabiru wouldn't look any near as pretty as it does now! - and we'd probably be reading about another light aircraft fatality!

[VH-XXX]

The little Jab in the article has a load of oil all over the nose leg assembly. Pilot was probably wondering what happened to his oil temperature and pressure...

[Volumex]

Shame about 7984, that does at lot of flying around AF.
ABC news reported that it collected a barb-wired fence around its undercarriage on the way in - good thing it stayed right way up.
Hopefully it will be in the air again soon.

[Flying Binghi]

Pigs were never meant to fly

They did quiet well for many a year. That 'dump and burn' thing were great to see..:cool:






.

[Perspective]

Probably why the ATSB are now conducting investigations like this

Research investigation into the reliability of light sport aeroplane engines (http://www.atsb.gov.au/publications/2013/ar-2013-107.aspx)

Most people probably would never air their true thoughts on a public
Forum about such incidents as this, I feel for fear of litigation.

Part of the problem for the ATSB is a lot of failures go unreported, plus
They don't tend To focus as much on recreational aircraft.

[Capn Bloggs]

Pilot was probably wondering what happened to his oil temperature and pressure...
I can tell him! The first went up and the second went down!

PS: What's a Jabiru??

[ravan]

....A large wading bird of the stork family????....:}

[Capt Basil Brush]

Quote:
Pilot was probably wondering what happened to his oil temperature and pressure...

I can tell him! The first went up and the second went down!

Not necessarily Bloggs. I can tell you from experience that in a BAE146 (I am sure you remember those) when you lose oil qty, the psi drops, and the temp drops. After arriving on 3 engines one day and quizzing an engineer, he said as the qty drops below a certain level, the oil level drops below where the temp sensor will read it - causing the oil gauge temp to drop. :)
(By the way this one was not the famous "catastrophic" engine failure, this one was shut down before it got to that)

[Ultralights]

rumour has it one of them ran out of motion lotion

[Aussie Bob]

There is an AD on Jabbies to replace the landing gear bolts every 500 hours. Perhaps this person forgot? It is an AD that you wuld ignore at your peril!

Or as an afternote perhaps this person was a contributing factor in the AD :confused:

[Wally Mk2]

Jabiru Are Bloody Inherently Really Ugly.....the true meaning:E:E

Wmk2

[VH-XXX]

The Jab undercarriage bolts had a size upgrade some years back (eg An4 to An5 or similar. Replacing them at 500 hours isn't so bad, $30 worth of bolts and nuts and maybe an hours work so not a big deal.

Locking up a main wheel under braking (causing skipping) is a major contributor to losing the undercarriage. It's the reason why the Vans RV 12 kits were recently modified as owners locking up the brakes were causing skipping and subsequent bending around where the undercarriage attaches.

So Aairbatic, I don't believe you would need to be concerned about the Jabiru undercarriage in general. There's a video on the front page of their website that shows the undercarriage during certification drop tests, very impressive!

PS: I may happen to own one :-)

Thanks Wally, I assume you don't want a ride then?
Oh that's right, not enough engines :-) !!

[Jack Ranga]

You bought a Jab?...............You Goose :}

[VH-XXX]

Mine doesn't have a Jab engine :-) Great airframe though, carries far more than it's empty weight in payload and at only 30hp per person. Try that in a 172 :-)

[onetrack]

There's at least one very unhappy Jabiru "crash-test-dummy" out there, who has instigated a sizeable website, asking a lot of questions about Jabirus that he wants answers to. I can't see him getting them.
Because the website owner hasn't indicated any recent updates to his website (and it appears a lot of his info is 4 to 12 yrs old), a lot of the info there may not be particularly relevant at this present time.

JabiruCrash.com - the story of my flight (and plane crash) in a Jabiru aircraft with Ron Bertram (deceased) - jabiru engine failure, Jabiru piston failure, ultralight (http://www.jabirucrash.com/)

Another item I found that is probably of great relevance and interest to Jabiru engine owners, is this following blokes claim that all factory Jabirus have their pistons installed backwards.

Jabiru have installed their pistons backwards (http://nvsr.com.au/articles/article10.html)

As it appears the Jabiru merely uses standard Holden pistons, I'd be concerned about the fact they're being used - rather than aviation-specific pistons - or tailored pistons.

I can recall a story from a bloke who worked on the Holden engine factory assembly line, from many years ago, telling me how Holdens had three markings for pistons as they lobbed in the basket for checking prior to installation. These markings were dobs of green, yellow and red paint.

The pistons that met all specifications precisely (including weight, a critical factor) were dobbed with green paint. These pistons went into export engines only.

The pistons that met specifications with a shove, went into "domestic production" engines. These pistons could have flaws in machining or casting, that were not deemed to affect engine life seriously.

Then came the final group of pistons, those marked with red. These pistons hovered between "just usable" and bordered on the, "to be scrapped" range - due to being so far outside specifications, it was dubious as to whether they would produce a full engine life.
I was advised these pistons were duly installed in the engines of fleet purchase or rental vehicles, and Govt vehicles. :(

[VH-XXX]

I've read that Jabiru Crash in detail and there are a lot of allegations and a lot of mud being thrown in the hope that some of it will stick. Not just at Jabiru but even at the guy maintainting it and questioning of his credentials (now deceased after Bankstown crash).

Long story short, the aircraft suffered an engine failure into a wooded area.

The first page of the Jabiru flight manual mentions to fly the aircraft at all times as if the engine could fail at any time. It's good advice :ok:

As for the pistons, Jabiru's answer is that they are the other way around because the rotation of the Jabiru engine is opposite to that of the Holden Commodore. They are not actually Holden pistons, they are "like" Holden pistons and they are modified from the supplier to suit the Jabiru engine.

Likewise, the Rotax 912 has 100% interchangeable rockers with the Ford Falcon :ok:

[rutan around]

Onetrack,
I'm surprised that someone of your age believes this nonsense-I can recall a story from a bloke who worked on the Holden engine factory assembly line, from many years ago, telling me how Holdens had three markings--------
Is this the same guy that worked for Mobil and helped suppress the engine that ran on water and later worked in a Condom factory where they put a pin hole in every 100th condom?
Before further efforts a made to ruin the reputation of a small Australian company perhaps you should acquire some knowledge on the subject.
This is shamelessly lifted from an article on modifying Holden engines:-
The majority of stock replacement type pistons have the gudgeon pin offset by about 0.060". The only reason for this is to reduce the tendency for the piston to slap after a cold start - the slight imbalance created by offsetting the pin makes the piston rock over relatively gently at TDC instead of "slapping" laterally from one side to the other. The amount of offset isn't great enough to have a material effect on performance, but despite this there is a persistent old wives tale to the effect that installing this type of pistons backwards will result in a power gain. If you remember any high school trigonometry (or you have a crank position vs. piston position vs. rod angle spreadsheet) you'll soon be able to work out that the small offset will have a negligible effect on rod angularity and piston thrust loads. And if you factor in the slight relocation of true TDC from reversing the pistons then the effect is even smaller. If you want to put the slugs in backwards go right ahead, you won't hurt anything. But don't expect the output to increase by any measurable amount. Of course all this only applies to stock style pistons - performance or racing pistons generally have zero offset.
Cheers RA

[Jabawocky]

onetrack

The Jabiru piston is produced in a plant that manufactures pistons for ACL. There are subtle differences but it is similar in most dimensions with the old 3.8L V6 Commodore engine, however the rest of the story is really a moot point.

The pistons are never the cause of any failure I have ever seen or heard about.

The biggest causes are likely to be the RAAus fleet and their tinkering owners.

If you think buying a C172 with an O/IO-360 in it means you have some highly scientifically special genuine Lycoming piston in it you are in for a shock. What is more it may have say a Superior Air Parts piston, and if you are ever in Texas and visit the Superior company you will find lots of parts, but not a factory, as they manufacture by sub contract from many and varied suppliers.

:ok:

[Dexta]

If you think buying a C172 with an O/IO-360 in it means you have some highly scientifically special genuine Lycoming piston in it you are in for a shock.

No, but if you look at an exhaust valve from a Jabiru engine and compare it to a 0-320 you might be in for more of a shock. Compare shaft diameters, note the head and tip welded on the Jab. Even Don from Jabiru commented that should a Jabiru valve get a bit of lead stopping it from seating correctly the head could burn off in about 15 minutes!

[VH-XXX]

No, but if you look at an exhaust valve from a Jabiru engine and compare it to a 0-320 you might be in for more of a shock. Compare shaft diameters, note the head and tip welded on the Jab. Even Don from Jabiru commented that should a Jabiru valve get a bit of lead stopping it from seating correctly the head could burn off in about 15 minutes!

One of the downsides of being both light and powerful.

A new valve design is out there and already being used, so let's hope that isn't something that will continue.

Luckily the valves are only $42 each versus $270 EACH for a Rotax 912 valve :ok:

[Jabawocky]

Don't get me wrong....I like my Lycoming IO540 :ok:

[VH-XXX]

This video is well worth the watch !

Young pilots praised for 'textbook' crash landing at Victoria Point - ABC News (Australian Broadcasting Corporation) (http://www.abc.net.au/news/2013-09-03/pilot-makes-emergency-landing-in-light-aircraft/4931182)

[Lookleft]

Just watched the video and a very impressive effort by the instructor. Although there was no sound he appeared to be pattering his way through the whole event. You could tell that his first concern after they stopped was how his student was going.:D

[Volumex]

Recalling the events, Mr Field said: "We're at 11,000 feet, we've got about a bit under two minutes before we're going to hit the ground at this point in time."

Don't Jabirus get dizzy up that high? and >5500 fpm descent rate is a smidge on the high side.

http://lh4.googleusercontent.com/-5AXLgsasVSQ/UiaZHBHRyXI/AAAAAAAAPCM/netcXbyHRjg/w727-h845-no/Jabiru+landing+-+ABC+report.jpg

Edit: I thought quoting it was enough :rolleyes:

[Jabawocky]

Young Doug is well used to landing in farm strips and his home airfield has an interesting approach for a normal landing. You should have seen it before the new big strip went in. So Old Man Ron Field should be proud of the young fella.

Well done Doug!

I like the use of the spare booster seats cushions. Very good work.

:D :ok:

[tecman]

The ABC use of the term "crash landing" is odd, too. All landings are controlled crashes, and this one seemed pretty well controlled. Seen worse at the Sunday PFL competition :)

One thing I don't see easily available are incident/accident reports for RAA aircraft (don't know if either/both of the aircraft in this thread were RAA). Having both RAA and CASA licences, I was discouraged to read in the last RAA mag that they think that reporting to members on accidents is an optional activity for the organization. I'd say it was core business.

Just as pertinently, I don't know of any single sources of individual aircraft and engine stats for this branch of aviation. If I want to know how my certified puddle-jumper compares in the accident stats, I can look up a few FAA or similar statistics. It's slightly inconvenient in that databases in different jurisdictions probably need combining, but at least there is data available publicly. If Joe Pilot wants to have a look at the stats for non-certified aircraft, to whom does he turn? For example, if I wanted to compare the Jab stats (across various models/engines) with those from other manufacturers, is the data actually available?

[Jabawocky]

If it has a VH tail whether it is Experimental, Limited or whatever it is logged and published.

If it is RAAus it is kept under lock and key by them. So you have no hope of answering that question.

The reason they do not publish is that they are not covered by the same laws that cover the ATSB. (read as ass covered)

[VH-XXX]

RA-Aus is quite a private association of which you need to be a member to view pertinent information. It is also one of the reasons why their aircraft register remains private except to the tax man. You can request to view the information on premises, but nobody wants to have to do that, so overall agreed tecman, it's a crap system.

The recent absence of crash reports in the magazine was due to someone "preparing them in their own time" and that person no longer preparing them! :mad:

Some basic reports have now been produced again but don't contain anything much more than aircraft type, location and TTIS.

I would happily volunteer to prepare some crash reports with specific details however the reports would only be as good as the information provided :( Getting them to the stage of being useful to others could be difficult unless there's something blatantly common such as an engine issue that could help someone else prevent their own failure in that area. In the GA LAME world, they've seen it all before and know what to look for so there's little value in a LAME reading crash reports for pistons falling off a Lycoming, but in the RA-Aus world where most of the pilots are the maintainers, the required information is somewhat different to the GA world.

As the FTDK says, nobody is yet to invent a new way to crash an aircraft. We've been doing the same thing since aircraft were invented and we still continue to repeat history :ouch:

[ravan]

Bl**dy good job Mr. Field!! (Volumex, if you have another look at the article, it says 1,100 feet)

[nitpicker330]

Excellent job boys, well done to walk away :ok:

Just a couple of observations from the video ( which may not be correct!! )

I've never flown a Jab and are not familiar with switch location:--

1/ they didn't appear to do to many checks after the failure? Is there any fuel pump to turn on? Mags to switch over? Mixture to play with? Fuel to check switched on? Could they have attempted to use the starter motor to get it going again?

2/ they appeared to already be at low power in a glide before the prop stopped as they didn't need to quickly lower the nose to maintain IAS. Indeed is it normal for the prop to stop windmilling in a Jab at normal glide speeds? ( unless it seized of course )

I am probably wrong but they looked way to calm under the situation.....!!

As I said at the top, well done on a successful outcome.

[Ultralights]

even without sounds, it looks to me like it would have been a very sudden failure, accompanied by a very loud and Instant BANG. maybe just a quick hit of the starter button/key would be enough to confirm that there would be no point in fuel/mag/throttle checks.

[VH-XXX]

1/ they didn't appear to do to many checks after the failure? Is there any fuel pump to turn on? Mags to switch over? Mixture to play with? Fuel to check switched on? Could they have attempted to use the starter motor to get it going again?


There is an electric fuel pump.
There are two ignition switches for the coils. Switch them on to ground and the engine stops. Not much you can do in a restart if they are already on.
No mixture control but it does have a fuel selector (on/off). He possibly glanced down to look at it but probably should have turned it off in preparation for a forced landing. (easy in hindsight)
Seems strange he didn't try the started (assumed) however as ultralight says she may have gone out with a big bang and a thump.


2/ they appeared to already be at low power in a glide before the prop stopped as they didn't need to quickly lower the nose to maintain IAS. Indeed is it normal for the prop to stop windmilling in a Jab at normal glide speeds? ( unless it seized of course )


A prop won't windmill on a Jab as there's a faid wad of compression.
At a guess from experience it would take 140 knots before it will even think about turning over.


All valid questions from a GA driver as Jabs are a little different to the norm.

No doubt he did a brilliant job of getting her down safely and he appeared to do a good job of briefing the pilot on the pending doom.

[Flying Binghi]

Reading a newspaper report, if correct, there is a claim of engine surging before failure. Suggesting fuel tap probably checked before vid starts.






.

[VH-XXX]

FYI - The cause was a cylinder popping off. The original article showed the front wheel spat covered in oil.

[Capn Bloggs]

All valid questions from a GA driver as Jabs are a little different to the norm.

Ouch! Ha Ha! :D

[tecman]

In general I'd agree with the comments re crash comics, XXX. It's always interesting to read someone else's analysis but there may not be much new. What would be invaluable, though, is an accessible database with some stats. For example, anecdotes might lead to the hypothesis that Jabs fall out of the sky regularly although, with better engines, less often than they used to. But I've been around science and engineering long enough to know that humans are incredibly bad at intuiting things like real risk and failure rates.

The only way for Joe Pilot to answer the question I posed earlier is to have access to an objective database and derived stats. If that database is confined to objective data, I don't see that the ass covering Jaba mentions need be a great worry. I'm not idealist enough to expect manufacturers to hand over the data they undoubtedly do accumulate but surely we might expect our representative organizations to be able to derive and publish basic summaries.

[nitpicker330]

Mmmmmmmm I let that observation go through to the keeper Bloggsy :hmm:

Wasn't sure if I should feel honored or insulted!!

[VH-XXX]

Oh, it certainly wasn't meant meant to be in any way insulting. Moreso many pilots that fly real GA engines like a Lycoming may not know that a Jab has coils and no mixture.

[nitpicker330]

No probs XXX, my day job is in an A330, I guess with the downturn in pay and conditions you could say Airlines are nothing more than "GA with Jets" now days!!! :ok:

[Kharon]

Watched the video with some interest: couple of things caught my attention.

The benefit of good sound training and lots of practice; apart from natural talent, the instructor has clearly done many hours of training students to forced landings; it was nice to see the "training" kick in smoothly during a real event; just another day at the office. The lessons, hard learned from way back, when engine failure and forced landings were a little more 'routine' than nowadays are still valid – even if considered, by some to be little more than a PIA or a box to be ticked. It's probably a once in lifetime event, but the stand out for me was the way the training and practice produced calm, confident management of what could, in less practiced hands become a nasty, sad event. Well done training, well done practice and nicely done that young man.

Another small, although highly debatable issue is that of circuit size; at one time it was that every landing was a 'glide' approach; the aircraft never any further away from the paddock than the glide distance. Now I'm just saying – there's merit in that the routine practice 'management' of the critical last few hundred feet (say from turning base) without donkey assistance reduced at least some of the pucker factor; and, the confidence gained from practice would be beneficial should the noise stop, sudden like.

Anyway – being totally ignorant of the "Jab", can someone provide the glide speed ? please, it probably was the camera lying (again), but the thing seemed to me to be a bit 'quick', I held my breath the last 3 seconds before touch; as I say camera and all that, but curious now.

Edit to add – even before the donkey croaks, at the first sign of 'bovver' the instructor is looking for a user friendly paddock, also it seems to me that whatever checks could be done, before during and after were done (although ignorance is bliss), watch the first few seconds again.

I do second the motion to have young men of that calibre on the flight deck; nicely done. Indeed, bravo and Choccy frogs all around....http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

[ChrisJ800]

Nice outcome into not the greatest paddock! Did anyone notice any signs of wind and direction? There is never a bonfire when you need one.

[Wally Mk2]

Interesting little Vid & under the circumstances a job well executed:ok:

A good reminder to all those out there flying SE at Low Alt (You JABBA:E). I wouldn't be trying to hard to restart the machine at that low Alt, the guy knew his priorities & stuck to them. Try a few basic re-start items if time permits once yr heading to a safe Ldg area otherwise consider that engine of no further use.
Many a plane has stalled/crashed due the pilot getting sidetracked trying to restart the donk whilst at a low Alt.
If I recall a Dove (DH104) out of EN a million years ago that went in just Sth of the drome, the pilot was continually trying to restart the failed donk after T/Off & 4got to retract the flaps after the donk failure ( I believe that was the story but could be incorrect), nasty outcome.

Wmk2

[Kharon]

Triple X-ray #36 "A prop won't windmill on a Jab as there's a faid (fair) wad of compression. At a guess from experience it would take 140 knots before it will even think about turning over." Good point Wally, I had (erroneously ??) concluded that due to the mentioned 'thumps', bangs and the way the lads immediately started searching for a paddock, that the donk was cactus; I noted the prop never even looked like budging during the descent. I demurred, due ignorance, to ask the question answered above, of compression ratio on the engine, just assumed (ass of u & me) it was seized. Don't know that a restart from that height after the 'orrible noises would have occurred to me. Paddock first, play later...:D...but it has been a long while, happy daze.

[MakeItHappenCaptain]

Not far off, Kharon. Biggest piece of the piston left is about the size of your thumb. I've seen it. If you can get the heat out of those machined heads more efficiently, they probably last a bit longer.

Always remember John McBride being asked what he knew about the Jabapu...
Walked outside and started looking around in an upwardly direction. When asked what he was doing, replied, "there should be one falling out of the sky around here sometime soon...":}:ok:

[China Flyer]

one falling out of the sky around here sometime soon

Pardon my ignorance, but are these aircraft "falling out of the sky" because of the engine they have fitted, or are you all talking about other issues as well?

I heard someone say that CASA is not responsible for investigating non VH- reg aircraft accidents; if that is true, can anyone point me in the direction of some accident/incident stats for ultralights?

[Jabawocky]

CASA don't investigate anything, ATSB do. CASA may make enquiries afterwards, but who knows where that would lead as they have no piston knowledge anyway if some of the reports in the last 10 or so years are anything to go by.

The Jab engine probably has a higher rate of destruction than others, but they do a lot of hours too.

And keep in perspective the one last week ran out of fuel allegedly. Hardly the engines fault.

Many problems seen in RAAus could be attributed to owner maintenance. And possibly the ones in schools with qualified maintenance too. Who knows.

MIHC has raised a point the heat transfer of the machined head may not be quite as good as the cast surface too, but I have a feeling it is more about airflow.

Airflow under a cowl does not do what you think it does. It defies simple logic and until you measure it and video it you tend to believe what looks like common sense. And it is very challenging when you see results that are the polar opposite.

For more info get the October AOPA magazine or the September Airsport Magazine, a great article in there.

[Kharon]

Cheers MIHC – interesting little puzzle. Soundly cursing the bump of curiosity, I went digging about for Jab information. Must say the POH is very good and the Jab folks seem honest enough about engine cooling. Most informative – Engine Cooling (http://www.jabiru.net.au/Service%20Bulletins/Engine%20files/JSL004-1%20Engine%20Cooling.pdf) – blurb was worth the few moments it took to read, Jabba is onto it. It's refreshing to see an issue being tackled openly, it's no wonder the little beasties are popular.

Hunted down the speed range – the POH I looked at placed max glide at 65 KIAS and engine out landing at 60 KIAS, which is comparable with similar aircraft. There are some interesting 'cautions' regarding in flight restart though:-

In the event that the engine is stopped during flight, it may be restarted by application of fuel & ignition, provided that the propeller is still windmilling. The propeller may stop windmilling below 50 KIAS.

Now, I've scratched that itch – well done Jabiru; nice to see that someone cares.

[China Flyer]

Thanks, Jaba.

[VH-XXX]

The propeller may stop windmilling below 50 KIAS.

I've never noticed that in the POH before. When they say "windmilling" I assume they mean it is turning over fully so to speak. At speeds around 100+ it sends to rock a little back and forth but usually won't turn over.

[Kharon]

XXX – I only looked at the J160 POH; it was the first one on the list.. It's really great that you can go to their web site, access and at no cost download lots of great information. Great service at the front end.

Section 3 - Emergency procedures (http://www.jabiru.net.au/manuals#operating) - J160.

3.3.2 Air start & Limitations.

In the event that the engine is stopped during flight, it may be restarted by application of fuel & ignition, provided that the propeller is still wind-milling. The propeller may stop wind-milling below 50 KIAS.

The Jabiru 2200 engine is a high compression (7.8:1) engine & therefore air starts when the propeller has stopped rotating, without the use of the starter, are unlikely before reaching VNE. Therefore, the following procedure addresses only air starts by use of the starter motor.

IMPORTANT – NO NOT depress starter button while propeller is rotating
There you go - last week I'd never heard of them, now I learned something.. Lurvely...http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

[VH-XXX]

Of course one could ask how I know that they don't windmill :cool:

[triathlon]

Great job at getting back on the ground safely. Well done mate

[Perspective]

What is extremely frustrating is a lot of engine failures go unreported.
Usually the engine is sent back to the factory for repair/warranty/upgrade
And returned to service. Many times I have had people say they have never
Had any problems with their Jabs, only to find out later that in fact they have had either one, or multiple engine failures.
And this is part of the problem for the ATSB at the moment.
Hardly anyone, probably 80% of the component failures go unreported.
Everyone wants to see an Aussie company succeed, but unless Useful Data can
Be collected and processed, it is difficult for them to get a true picture of what
Is happening out there, and make required recommendations.

[rutan around]

Perspective
Everyone wants to see an Aussie company succeed, but unless Useful Data can
Be collected and processed, it is difficult for them to get a true picture of what
Is happening out there, and make required recommendations.

You are absolutely correct. I've heard rumours that Jab engines more often tend to lose power rather than quit outright but I have no data on this.( Sorry Jabba ) http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/sowee.gif It would be in everyones interest to know what caused every partial failure and every complete failure. If it's a design fault---- FIX IT. If it's an installation fault ----FIX IT If it's an operator fault--- TRAIN THEM
Cheers RA

http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/reply_small.gif (http://www.pprune.org/newreply.php?do=newreply&p=8032758&noquote=1)

[Kharon]

I imagine the Jab factory has all the data – has anyone approached them?. The data would be sensitive but handled properly it could be turned into a positive. The other option is owners volunteering the info to a central data base; I don't believe it's illegal have "engine problems" but it would be naughty not to share.

XXX – .. :D....I did, in my own way get it; - http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif - I'm slow, but not quite as

Thick as some.

[poteroo]

Perspective you are absolutely correct. I'd have said 66% are 'unreported' if the subsequent emergency turns out satisfactorily and there's no public reporting. It's what is supporting the used market.

Kharon The forced landing was really well done. As it was a J170 - 60KIAS is about right for the final approach as it wasn't clear how much flap had been deployed. It looked a rather 'flat' final as they just cleared that shed - so maybe they only had half or less. Whatever - it worked on the day.

With the J160, speeds are usually up by 5 kts on the 170. Depending on weight at the time 65-70 will work fine. More often than not - the trim will be fully used to hold the attitude so it's more pilot effort to fly them any slower....probably a fair safety feature.

happy days,

[VH-XXX]

55 knots on final for our fleet of J170's. 50 knots for a short fielder. With a stall speed of <=45 knots, it makes perfect sense.

Anything higher than that is at your peril and one of the reasons why so many Jabs have had runway excursions; schools are often teaching them speeds that are far too high and when things go pear-shaped, it all happens very quickly.

At a guess his speed was probably about right as he held back-stick for quite a while and if he had been too fast, it would have started climbing.

[Wally Mk2]

I wonder whether those auto umbrella thingy's that pop out of the top of these toy planes should be more widely used.
I imagine you have a choice with those, you either pop it out if there's no suitable Ldg field within an assumed gliding distance or you go for a conventional crash Ldg (as the press would say). Cost no doubt is the deciding factor, not safety.

If someone could come up with an engine design along the lines of the old tried & proven Lyc's & Conty's which are almost bullet proof for these toy planes then they would be worshiped:)

Wmk2

[Tankengine]

1.3 VS?:confused:

[LeadSled]

Tankengine,
Precisely, but the "certified" stalling speed is CAS, not IAS, I wonder what the the static error correction is like at those low speeds.
I well remember older C-172, the IAS stalling speed was almost "off the clock", but corrected for static error was "as per the book".
Tootle pip!!

[VH-XXX]

J170 is 39 knot stall so 51 knots is about 1.3.

I stand by my mathematics.

[tecman]

Wally, I know you're a sceptic and I'm no evangelist, but I give 'quiet thanks' for my Rotax 912 S2. After years of flying the Lycs and Continentals, I admit that it took me a while to believe that the little donk was a good thing. I've seen the religious debate in other threads and have nothing much to add, except perhaps that the Rotax has done well when compared in reliability and maintenance cost terms with my other engines. My personal philosophy is to take the operation and maintenance seriously and, even if I had a choice, I'd never have my engine maintained by other than a LAME - and one I trusted. If anything, I'm even pickier with the 912 maintainers. A less agricultural touch is definitely the go!

I hate to rely on anecdotes (for the reasons mentioned in my previous advocacy of maintaining a proper RAA database) but the best information I could get when looking at alternatives is that the Rotax does do better than the smaller Jab engine in reliability terms.

[rutan around]

Lack of data is a huge problem. In theory the Jab should be more reliable simply because it has less components which could fail. It has no radiator and associated plumbing, no gearbox, no injectors , no injector pump and has a very simple ignition system. There's not much left to fail.:ugh: Is it possible it's perceived high failure rate is simply because there are a lot of them around. A lot of Holdens crash but there a lot of Holdens.
Internal combustion engines have been around for well over 100 years. It shouldn't be too difficult too pinpoint Jabs problem area if indeed there is one.
Human nature presents another problem. A mistake be it in installation, maintenance, engine operation or in flying skills is always the engines fault if nobody else saw it happen.http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/badteeth.gif Could human error be why so many incidents go unreported?

[404 Titan]

I had an engine failure in a J160 in about 1994. The studs holding one of the cylinders onto the crankcase clean pulled out of the crankcase. Luckily for me, like the two young men in the video, I had a happy outcome. It would be interesting to know if the studs pulled out of the crankcase like they did for me.

Needless to say you would have to drug me to get me into one now.:eek::uhoh::oh:

[Jack Ranga]

If you want a Jabiru, buy a paddock

[rutan around]

Titan,
Did you report the incident? Did it make it on to anyone's data base? If not why not?

[Perspective]

Rutan.

"Is it possible it's perceived high failure rate is simply because there are a lot of them around. A lot of Holdens crash but there a lot of Holdens.
Internal combustion engines have been around for well over 100 years. It shouldn't be too difficult too pinpoint Jabs problem area if indeed there is one".

I see where you are coming from Rutan, but in my experience, the failure rate
Is definitely not perceived.
And yes, light aircraft Engines (lycoming,continental) have been around a long time, time enough to put all of the lessons learned in to their Engines, long ago.
Why reinvent the wheel. I'm not saying you should not attempt to build your own engine to suit your own needs, but surely you would build on lessons past.

I remember when Rotax engines became more common, I didn't think too much of them at the time, but they have proven themselves to be an extremely reliable, well Engineered little engine.

[rutan around]

Jabba,
Some interesting data. 7571 pruners have taken an interest in Jabs problems.Only 372 have even looked at your engine management course invitation. Does that mean they worry that there is a problem but aren't interested in possibly finding a solution? Or does it mean they have complete faith in Saint Instructor who was trained by Jurassic Instructor?:ugh:
RA

[Jabawocky]

Rutan

Smart, bright and quick witted as well as very adventurous are qualities of both Mr Rutan's.

You however posses these qualities it seems, but have too much time on your hands to notice! :}

[peterc005]

Maybe this is a solution:

Jabiru Twin first taxi - YouTube (http://www.youtube.com/watch?v=Ccb5mEIX9ck&desktop_uri=%2Fwatch%3Fv%3DCcb5mEIX9ck&nomobile=1)

[rutan around]

Perspective,
Why reinvent the wheel. I'm not saying you should not attempt to build your own engine to suit your own needs, but surely you would build on lessons past.
I don't think there is anything wrong with trying to improve the wheel. eg Jabiru's excellent power to weight ratio.You just have to be careful and move quickly if or when a problem emerges.
Some improvementsmade by Continental and Lycoming have cost owners a disasterous amount of money and even cost some lives before those companies were forced kicking and screaming to rectify the problems. Lycoming's crankshafts and Continental's belled out cylinders come to mind.
RA

[Wally Mk2]

Man have they made a fairly ordinary looking toy plane even uglier with that twin thingy, it looks like a strange fish with warts!:)

A twin Jabby, twice the problems:)

'Tecy' I gather the Rotax is pretty much well known these days having been around a day or two & there would be few if any surprises out there for the owners of same.
I read with interest the Bugatti Veyron has a W16 donk returning 3MPG at full tilt (250MPH+ on 1001 HP) & the engineering design that has gone into that machine (fascinating YouTube on it all) actually has produced a stunning 3000HP (2000HP gone due heat) so why not have some higher level of design done for Aero engines, after all a Bugatti donk fails ya pull over call yr lawyer & sue the crap out of Bugatti, yr garden variety Jabba junk donk fails yr family calls the lawyer!

There's 3 basics things needed for typical low comp 'infernal' combustion engine to work, Air (that's a certainty providing ya don't clog the inlet up!) fuel & a source of ignition but you would think after a 100+yrs of stuffing around there's still problems with the basic man made design, time to start all over again I think & lets all vote Jabba Dabba Doo as the head of the new technology, over to you Jabbs & try not to waste much energy on heat will ya buddy! :)


Wmk2

[Jabawocky]

..........thats would be a disaster Wally :}

[Perspective]

Rutan,
They have a way to go before they even
Get up to the wheel, let alone improve on it!
I can easily give you a half dozen reasons why.
And We have tried to "assist" with product improvement,
The "wheel" turns slowly

[VH-XXX]

And We have tried to "assist" with product improvement

Therein lies one of their biggest problems, all of these aircraft owners with better ideas than the engine designer and manufacturer (whom are not the same companies).

You've only got to talk to the manufacturer to realize that he knows far more about engines than 99% of the operators will ever know, but yet operators of these engines that have rebuilt their old motorbike or jet ski engine usually believe that they know more than the manufacturer. Many of the "improvements" suggested by operators of these engines are a joke and if other operators followed their advice they would end up in a box (and I am not referring to the engine being in a box!)

[rutan around]

I attended a forum at Oshkosh on Jab cooling presented by Robert Gutterage. Maybe most of Jabs problems are insufficient cooling going undetected due to incorrect CHT information being presented to the pilot. Certainly Robert presented a very well researched forum backed up by hard data.Note :- He had data--- Not a bunch of ' I thinks ' He showed slides of what he did to solve the problem in his aircraft as well as before data.
Apologies to Tim Juhl for pinching the following from a forum on Jabs.
(Remember-stealing articles from one writer is plagiarism----stealing from many is research.)
I attended a forum at Oshkosh where a fellow discussed his research on cooling a Jabiru 3300. He had compared the spark plug washer type CHT sensors to ones directly in the head and showed that they pretty consistently indicated CHT's about 70° cooler than actual temperatures! If this is the case, Jab operators could be cooking their engines while thinking that their CHT's were within safe limits. He ended up designing a cooling baffling system that is nothing like what comes from the factory and claimed that was the only way he was able to get the CHT's under control.

I wonder what the rest of you Jabiru 3300 operators have to say about this? I'm not flying mine yet but will be getting ready to hang it soon.

For a summary on the fellow who made the presentation check out EAA AirVenture Oshkosh - The World's Greatest Aviation Celebration (http://www.eaaapps.org/presenterinfo.aspx?id=1973)
EAA AirVenture Oshkosh - The World's Greatest Aviation Celebration (http://www.eaaapps.org/presenterinfo.aspx?id=1973)


It's worth looking at the last web site outlining Robert's qualifications.He's the right man for the job.
For all those who want to junk the Jab engine for as yet no clearly defined problems it would be good if you reflected on the Wright R3350 turbo compound engine used in the B29 and in the Super Constellation. When those engines were first used their TBO was typically 200 to 600 hours.Ouchhttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/boohoo.gif After they learned to operate them properly (essentially by running them lean of peak) they were often getting TBOs of 3,600 hours:D all with 1940s technology. Lycoming and Continental should hang their heads in shame.
RA

[Dexta]

The difference between the companies (Rotax & Jabiru) attitude to failures, in my personal experience, is chalk & cheese. Rotax 912 with approx 1300 hours had problems, symptoms indicated crankcase fretting, called dealer/factory... "We thought we had solved that issue, please send the engine in and we will replace the crankcase free of charge, we would like to get to the bottom of this...".
Jabiru 3300 in factory built aircraft at 280 hours, meticulously maintained etc. en-route ran rough for 10sec then stopped dead, found a flat bit of ground and walked away. Aircraft sent back to factory for repair by insurance Co. before we got a good look at the engine. When we asked what happened we were given the run-around, then we were accused of "thrashing" the engine, then they "lost" the bits, and when we insisted it be sent back did they said we could have a new engine for free minus rebate for hours. We never found out what went wrong (I suspect it dropped a valve).
One company seems to want to improve reliability, one want to cover its behind, ones reputation seems to be growing, one seems to be getting worse....

[rutan around]

Sorry I can't get Robert Gutteridge's web site to cut and paste so here it is.
Name: Robert Gutteridge Title: Mr. Biography: Academics: BSME degree, registered Professional Mechanical Engineer (retired), career involved machine design with emphasis on heat transfer in both heavy industrial and electronics industries. Aviation: 32 years experience, ground up restoration Champion 7FC, extensive maintenance on Cessna Aircraft including engine overhaul, built a Jabiru E-LSA kit with many redesigns to enchance safety and pilot convenience. Completed 16 hour LSA course for Repairman Inspection Airplane, 2 day course covering Jabiru Engine Installation & Rebuild. Currently serving as an EAA Tech Counselor. Volunteer at Pacific Coast Air Museum on aircraft maintenance crew. Private pilot with instrument rating, 2200 hours flight time. Presentations: Wednesday, 7/31/2013 - 8:30 AM - 9:45 AM - Forum Pavilion 01 - Map (http://www.eaaapps.org/images/K09.jpg)
Cooling the Jabiru 3300 (http://www.eaaapps.org/moreinfo.aspx?id=6322) - The presentation will cover my three year effort investigating and improving the cooling of Jabiru's 3300 engine. We will begin with upgrades to the temperature sensor equipment which improved the accuracy, consistency and usability of those readings. Tell tail signs of over heating will be discussed as well as the effect of high operating temperatures on metallurgical properties and its possible consequence. Finishing the forum will be a discussion of my new baffling system and the results obtained.
Presented by: Robert Gutteridge (http://www.eaaapps.org/presenterinfo.aspx?id=1973)
* Add this Presentation to My Itinerary (http://www.eaaapps.org/presenterinfo.aspx?id=1973&add=6322)

[Dexta]

The problem is though, with the stupid LSA regs, you cannot modify your aircraft if you want to use it for training (and keep it as a 24- rego). So you can't fix the cooling, fit fuel injection, fix the intake plenum etc. unless the factory approve mod. If the factory doesn't think there is a problem, they are not going to approve the mod.

[Perspective]

XXX. No assumptions please.
No, I'm not a Jab owner, but a couple of decades
Maintaining aircraft you learn a thing or two.
One of our team has probably some of the highest hours,
Hands on maintaining these things also.
As I said, we all want to see them succeed,
But you have to open to industry, particularly considering the
Experience gained in the field.

[onetrack]

In my experience, there are too many manufacturers who are quite prepared to produce a mechanical product and release it for general sale without the necessary extensive reliability testing. They rely on the client being the "test bed".

In the case of aircraft engine manufacturers, I would suspect that the smaller the manufacturer, the lesser the amount of effort and $$'s spent on reliability testing.

There should be free and frequent disclosure of any mechanical or design-related aircraft engine problems, and a database available online. The dissemination of knowledge and discussion of faults should override any need to protect a companys reputation.
After all, we do live in the Information Age, don't we? - not the Dark Ages!

[404 Titan]

Rutan around

The Jab was VH registered and was reported at the time as per the regs.

[rutan around]

Titan
If all problems were reported as yours was and the information made generally available faults might be eliminated much more quickly than appears to be the case now. You have probably seen the AD found at the address below even though it came out 7 years after your potential disaster. It makes quite interesting reading.
https://www.google.com.au/search?q=Jabiru+engine+studs&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&gws_rd=cr&ei=9RMsUpejO8ehigeI24GoAw

[Lancair70]

I know the story says Cessna, but heck it was white, had a single engine and the wing on top, A Cessna to any journo. However I have it on good authority is was a Jabiru

Emergency at Ballina airport as plane flips near runway | Northern Star (http://www.northernstar.com.au/news/emergency-ballina-airport-plane-flips-near-runway/2024316/)

[Volumex]

7984 is back in the air again. :ok:

[spinex]

Volumex do we know what caused it to fail? So far makeithappencaptain is the only one that has offered a first hand account of the damage - or is this another that will disappear into the Bundy Triangle?

There is a lot to like about Jabs, but having flown 7984 I eventually decided that departing AF to the East in a Jab was outside my comfort zone.

[Volumex]

No idea - I just heard it doing circuits on AF TWR frequency this afternoon.

[VH-XXX]

If you are referring to the one in the video, it popped a cylinder / broke a stud. Hence the oil on the front wheel spat.

[spinex]

Cheers XXX, that's the one I meant.

[spinex]

I hear the rumour mill is being fed the line that this engine had old style through bolts that should have been changed as per SB, but weren't hence the failure? Anyone know any more - smacks of the standard Bundy response of operator/LAME error, but who knows.