Bad Experience with Jabiru

[Old Koreelah]

I assumed that Col, but it doesn't make sense. Lots of Jabs have been sold in North America and I'm sure there's more than one in each of Oz and NZ. S Africa is also an important market.

 

 

[coljones]

I assumed that Col, but it doesn't make sense. Lots of Jabs have been sold in North America and I'm sure there's more than one in each of Oz and NZ. S Africa is also an important market.

If you believe the naysayers you would form the impression that these are mass graves of Jabirus that engaged in ritual mass suicide after discovering that they weren't Rotaxes. Oh, the shame of not being born with 4 little coloured hats. ??

 

 

[turboplanner]

Sounds like more obfuscation to me; I'd suggest they are the locations of Jabiru dealers around the world.

 

This thread was about an experience in Australia so there's not a lot of point in beating up overseas products where nothing really stood out as a cluster.

 

Including production figures is a waste of time since many of the older engines which reached TBO,  and were replaced have to be taken out

 

Many of the older aircraft have long gone to the tip and have to be taken out

 

Every engine which failed and was replaced by a new one has to be taken out

 

The overseas engines which had no problems has to be taken out

 

This thread was about problems a person had in Australia, so it's a question of how many Jabirus are operating in Australia

 

The public statistic is that RAA state that there are almost 3500 registered aircraft. They did NOT say 3500 Jabirus, so you have to take away all the other makes of engine before you get to the number of Jabirus registered in Australia, and that is the group that would have any personal interest in the status of their aircraft today.

 

And the bottom line about that group is that we are not seeing any reports about the new engines failing on the trip down from the factory, or failing full stop.

 

 

[Bruce Tuncks]

My old Jabiru engine ( It was one of the first to come with an oil cooler ) has been completely reliable in the air ( I say it this way because I did damage it with overheating  on a ground run ) and is coming up to 700 hours. All the compressions are good and there are no oil leaks.  One day I will replace it with the latest alloy Jabiru engine and will have a new engine in a 17 year-old airframe.

 

The old plus new engines will be cheaper than one rotax would have been, and I don't have to feel ashamed of having a cultural cringe.

 

 

[Jabba jenny]

Bruce, I couldn't agree more!  My old Jabiru is 20 years old, airframe done over 6000 hours (was a training aircraft for a few years) and current engjne now done 800 hours. I'm pretty sure this aircraft went through the same rough treatment as most training aircraft, so it proves how tough and forgiving they really are. My engjne still runs beautifully, no leaks, great pressure.  I wouldn't hesitate to buy another Jabiru, engine or aircraft.

 

 

[kgwilson]

Jabiru have mentioned that there are around 1000 Jabirus operating in Australia. Of the 6500 engines produced there was a large contract with a US based UAV company for some years. I don't know if this is still happening

 

 

[Old Koreelah]

Jabiru have mentioned that there are around 1000 Jabirus operating in Australia. Of the 6500 engines produced there was a large contract with a US based UAV company for some years. I don't know if this is still happening

At NatFly one year Stiffy told us about the use of Jab engines by the US military. When evaluating the engine, they flew a standard Jab to (from memory) 22,000ft and found it was still climbing.

 

They used a variety of engines in different drones. One nasty trick was to regularly send one out powered by the incredibly noisy Norton rotary engine. After the other team got accustomed to its habits, they'd send out a quiet Jab-powered one and give them a big surprise.

 

 

[fly_tornado]

UAV using avgas?

 

 

[Jabiru7252]

I had a quick watch ! I never saw carb heat go on ! I never saw fuel pump go on ! I saw a quick response of communication ! I saw little effort to slow this aircraft on landing as the stick was going back and forward ! Please tell me if I saw this wrong and why !    

Very few people, very few, ever react the way we are taught, especially the first time things go pear shaped. That's well known to anybody who has studied human factors to any real depth. How many hours did this guy have? How many engine failures did he experience? 

 

 

[Camel]

Very few people, very few, ever react the way we are taught, especially the first time things go pear shaped. That's well known to anybody who has studied human factors to any real depth. How many hours did this guy have? How many engine failures did he experience? 

I have had two problems relating to partial loss of power, one was ice on take off caused by excessive taxi time and required heat instantly and it still coughed and spluttered for a while as I lined up for landing, applied heat, swapped tanks and checked mixture rich, it came back into life and I climbed, failure to do those checks, mainly heat would have ended up in a rough paddock.  Sure no one is perfect and we forget but some things like carb heat, pump on and mixture rich are very important.  The other incident was on take off and it was a human factors mistake, Lycomings can foul plugs taxing so I leaned while taxing, checks done and left it lean until ready, well guess what happened, when the engine sputtered and near died I did the checks and put mixture in first as I realized I had made that error ! 

 

My point is old mate in video could well have had carb ice and nothing was done ! He had a engine failure and maybe it was preventable or should I say recoverable.  My training and every BFR involved a simulated engine failure and my GA instructor would pull power on take off if I took my hand off the throttle. 

 

 

[pmccarthy]

My understanding is that you can’t lean a Lycoming while taxiing. At taxi it is running on the idle jet. If you pul mixture there is no increase in CHT until you hit the idle cutoff. Then you can get some leaning if you are careful prior to cutoff but it is not advised by Lycoming. Above 1000 rpm it transitions to the main jet and then the mixture control works.

 

 

[nickduncs84]

I have had two problems relating to partial loss of power, one was ice on take off caused by excessive taxi time and required heat instantly and it still coughed and spluttered for a while as I lined up for landing, applied heat, swapped tanks and checked mixture rich, it came back into life and I climbed, failure to do those checks, mainly heat would have ended up in a rough paddock.  Sure no one is perfect and we forget but some things like carb heat, pump on and mixture rich are very important.  The other incident was on take off and it was a human factors mistake, Lycomings can foul plugs taxing so I leaned while taxing, checks done and left it lean until ready, well guess what happened, when the engine sputtered and near died I did the checks and put mixture in first as I realized I had made that error ! 

My point is old mate in video could well have had carb ice and nothing was done ! He had a engine failure and maybe it was preventable or should I say recoverable.  My training and every BFR involved a simulated engine failure and my GA instructor would pull power on take off if I took my hand off the throttle. 

It was a blown cylinder from what I was told. He landed and both he and the aircraft were fine. Pretty long bow to be pointing any of the blame at the pilot. 

 

 

[Bruce Tuncks]

Nick, I would like to know more about the "blown cylinder". Maybe there was poor maintenance involved.

 

A mate of mine once had an engine failure ( starting at an exhaust valve ) in a Jabiru and I asked him how the engine felt on the turnover test that morning.

 

He had never heard of the turnover test even though Jabiru have it as a requirement.

 

This was so bizarre that I looked into it and came to the conclusion that some ex-GA instructors, used to impulse magnetos, have erroneously transferred a turnover ban to Jabirus.

 

My bet is that that engine which failed would have given plenty of warning. 

 

 

[Yenn]

Surely you do a turnover test with a magneto equipped engine. Switches off, fuel off, mixture cut off and gently pull through. You will hear the clack of the magneto firing at TDC and usually nothing untoward happens. I have been flying 50 plus years and am still to have a cylinder fire at pull through. Without the pull through you are denying yourself of any knowledge of valve or rings condition.

 

As far as leaning during taxi, I do it always and I set it so that it runs smoothly at idle and if I push the throttle in it will gasp and fail. Set it so that it is only slightly leaned and you can get to full throttle, but not full power. Kep doing that through a take off and you could well end up with detonation problems.

 

 

[facthunter]

Blown cylinder is not a very enlightening description. Sometimes the engine can still  give some power  with a damaged cylinder, With other damage it will destroy the motor . If the piston is still able to go up and down you are better off than if the cylinder has detached from the base. A lot of Pratt and Whitney failures were shrink band (cylinder head to cylinder join) this is due old age and fatigue of the metal. If a valve stem fails (relatively common on a jabiru as a cause of failure) it's usually the result of overheating (high EGT's) and stem stretching. and is a result of other factors. peculiar to how it's operated. The manually adjusted valves  would show this in the disappearing of the clearance settings. The hydraulic lifters mask this until their range of automatic adjustment is exceeded. then they close up When that happens the sealing will not  occurr and the valve will get excessively hot and maybe cause detonation by  acting as an ignition source. If the valve head comes off it goes through the crown of the piston which tends to break up, and the motor destroy itself..

 

   IF the motor develops a vibration or noise, land soon if possible, as it's not likely to get better by itself.   A motor that's been over revved or overheated should be inspected even IF it's still running OK. Nev

 

 

[nickduncs84]

Just passing on what I was told from the pilot. Personally for a low hour pilot I thought he did extremely well. I won’t get into the religious debate around Jabs. Personally I loved flying them and bang for buck the 230 has to be the best aircraft on the market. Speed, climb performance, baggage space. It really is a great plane. That being said, I don’t have the same confidence in the engine as I do a lycoming/continental. I know that’s a religious debate in itself. Bruce, you are probably right about the maintenance side of things and I reckon if I had your experience and actually knew what I was doing, I’d be just as comfortable as you. I guess to a simpleton jab mx seems to be more mysterious than a lycoming. BTW I don’t reserve this opinion for jabs only. I wouldn’t put my family in the back of one of those piper Malibu’s for example. 

 

 

[Bruce Tuncks]

Nick, no matter what you fly, the daily inspection is the real line of defense and you don't need to be an expert to have a suspicion that you check out before flying.

 

I reckon lycomings are good engines too and accept that they are tougher than a Jabiru,. But the gliding club here sure has had problems with them over the years. At one time, we were having cracked cylinders every few weeks. Sure, glider towing is tough on an engine.   We have a Jabiru with a towhook which is not used.  Sometimes the 260 horse lycomings are short on power, so a 120 horsepower Jab is too low-powered for a 2 seater on a hot day. On test, it did ok with a Libelle on a cool day. And I reckon Yenn has great advice on checking a magneto engine. I'd do that ( with fear ) if I had one.

 

 

[ODowneyEng]

I had a quick watch ! I never saw carb heat go on ! I never saw fuel pump go on ! I saw a quick response of communication ! I saw little effort to slow this aircraft on landing as the stick was going back and forward ! Please tell me if I saw this wrong and why !    

My same observations