CASA proposed operational restrictions on Jabiru Powered Aircraft.

[motzartmerv]

The current CASA discussion draft is causing huge amounts of comment and debate.

 

I am interested to know how much support there would be in our ranks for this action by CASA.

 

Obviously if implemented, this action will be devastating to many in the RAA , both privately and for operators, FTF's etc.

 

As usual, the Jabiru engine debate has divided the community, but I want to know if even the so called "jab bashers" would support this drastic action by CASA.

 

 

[Guest Howard Hughes]

Clearly something needs to be done, just what (and to not devastate RAA at the same time) is the question.

 

 

[bexrbetter]

I do not support the proposed action but I agree some action needs to be taken.

 

 

[rgmwa]

This issue has attracted some attention in the US as well, and it seems to me that post #24 in this link to the VAF forum sums up the situation pretty well. http://www.vansairforce.com/community/showthread.php?t=119556&page=3

 

rgmwa

 

 

[turboplanner]

Since we haven't seen any CASA decision yet, which could range quite widely or cold be exactly what people want, this is a little premature, but one consideration is that it could save your life, your partner or friend's life and a great big lawsuit, for the sake of still flying, but going quietly until there is a fix.

 

 

[kgwilson]

I have a brand new Jab 3300 in my Sierra which has yet to have its first start. I bought it with the knowledge that there were issues with Jab engines. I downloaded and read the NASA 3405 report on "Aerodynamics and cooling of horizontally opposed aircraft engine installation", 152 pages of extremely detailed and thorough analysis completed in 1981 and I have taken a very pragmatic approach to the cooling system using Garry Morgans intake ducts, a separate NACA duct intake for the large 7 row oil cooler mounted at the bottom of the firewall and a 60mm diameter intake in line with the top of the sump. I also have Garrys Cobra head with a separation vane in front of the carb intake which allows easy change by bending it one way or the other if the left side runs hotter than the right or vice versa. The airflow is smooth from intake to exhaust which is over 1 metre wide & 100mm deep with a 20mm suction lip.

 

It is my opinion that most of the issues have their root cause in overheating. I have flown Garry's aircraft and they do run cool. There are none in flying schools but it seems that none of Garrys aircraft with Jab engines have had problems. The oldest Jab at our airfield has one of the thick finned head 3300 engines but does not have the Jabiru "fence" in front of the cylinders which turbulates the inflow and has a very large exhaust with suction lip and has more than 950 trouble free hours on the clock.

 

I voted for option 2. There are issues and they need to be dealt with. CASA in its proposal is way over the top when they did not have any data on which to base their decision (still don't to my knowledge) & they have proposed to contravene the rights of home builders to install an engine of their choice.

 

 

[turboplanner]

When you say "none of Garrys aircraft with Jab engines have had problems" - you didn't read Bigglesworth's comments?

 

 

[Jabiru Phil]

Owner pilot of a Jab I know of has an adjustable cooling system.

 

He just winds out or closes the aperture to balance the temp.

 

Bit like the old Fordson kerosine tractor system that I used in the early 50's.

 

As did most Kero tractors of that era.

 

According to him, it works a treat.

 

Phil

 

 

[Yenn]

When we see the results of CASAs research we can get abetter idea of how necessary it was. CSA has said that it respects Jab engineering, or words to that effect. They have also given varying numbers of incidents with engines, but so far no actual numbers o failures. Nor ofreasons or failures.

 

With all the bad mouthing of Jab that has been going on in the past CASA would be forgiven for acting, but have they got the right information.

 

My personal opinion is that through bolt failures and valve problems seem to be the danger areas. Running on mogas can cause detonation as you never know what the quality of the fuel is and that could be the cause of the through bolt failures.

 

 

[motzartmerv]

Yes Yenn, the fuel issue is very much on my radar too, although, there are several examples of 100% Avgas jabs having the same issue.

 

 

[facthunter]

Avgas is a controlled product . Mogas is anybody's guess. People can adulterate it at any stage of it's distribution It also goes off and can have a vapour lock problem.. Nev

 

 

[dazza 38]

My KTM 1190 will burn a hole in a piston if the fuel has ethanol in it. I use Caltex premium 95 I know it doesn't contain any Ethanol and it is quality fuel.

 

 

[facthunter]

IF you run any fuel containing ethanol and your engine management system doesn't compensate for it you will be running LEAN. Nev

 

 

[Yenn]

I am surprised that avgas run engines would have through bolt failures. maybe my theory is not correct.

 

 

[planesmaker]

I doubt it's fuel related, if detonation is a problem surely there would be damage evidence on pistons. Doesn't take long to start to melt a piston with detonation.

 

Dmech could be on to something with resonance.

 

One thing I am sure of , Jabiru don't know what is causing them to break. I had to just shake my head when they put out a SB changing the nuts for nuts with more thread???? It wasn't the nuts that were the problem. Just fitted new bolts to 2200 and they came with bigger 12 point nuts that required using a 1/2" crows foot(instead of 7/16"). Bolt diameter remained the same, yes that should fix it,really?Tom

 

 

[Downunder]

Do they increase the torque when putting on bigger nuts?

 

More thread and bigger contact face would reduce the actual tension/torque if the same spec was used, to my thinking anyway as there would be more friction.

 

Maybe not enough to worry about.

 

 

[planesmaker]

Contact area the same although they have increased torque and no loctite. Bigger nut meant we had to acquire another special tool. Tom

 

 

[jetjr]

the whole bigger nut thing is old history

 

I believe there were some early failures where bolt was stripped, so not as stupid as made out to be

 

As it now turns out that isnt the problem

 

Never heard of the bigger nut diameter, doubt a bigger one would fit considering old issues with barrel distortion due to some nuts having less radiused corners.

 

There are larger bolts in new versions

 

The current proposal will promote more of these urgent fixes, costing owners dearly will little result

 

 

[Downunder]

Someone should make up a "family tree" type flow chart with all the mods.....would be interesting...

 

 

[SDQDI]

I was just wondering what actions people had in mind when they said they don't agree with CASAs methods but still want something done? Personally I would like to see some acknowledgement of 19 or exp registered and for those aircraft to continue without further restrictions but other than that I think they are somewhere close to the mark.

 

How do you get jab on board if what you are doing doesn't affect them?

 

And finally how many jab operators would need to be affected to economically force jab to act? I ask that as if no one is affected then obviously nothing would need to happen but how many is too many and how many is enough?

 

Obviously I don't have any solutions but with everyone saying something must be done just not this surely someone has a suggestion?

 

I don't mean to inflame this conversation but would like some constructive suggestions.

 

 

[turboplanner]

It's a good point SQ, everybody wants to go to heaven, but nobody wants to die.

 

Although Motz's poll has only drawn votes from 1% of the members, it's good to see the level of responsibility expressed by the majority of the voters.

 

While the situation has been out of our hands all along, and will be decided between CASA and Jabiru, it would be worthwhile to look at the constructive suggestions you recommend.

 

 

[facthunter]

I'm not going to suggest anything specifically technical here as I don't think it is appropriate to go much further than I already have.. The ISSUE appears to be a disconnect between the two parties who are involved in two versions of the engine. It is probably about stubbornness and money. Possible the CASA should force an arbitration or deal from them to address any outstanding faults that can be defined. CASA may have no legal means of doing this.

 

Processes that get more factual knowledge (is there any other kind? but you know what I mean) to all operators and owners would help.

 

Train and approve a number of L1's and L2's on the specific issues that are agreed. and use them as a basis for spreading information.

 

Have qualified people like from Deakin University etc do some analysis of questionable aspects of the design as/if discovered. No design is perfect.

 

I'm going to break my rule. (First line on page) See if a front mounted flywheel/ starter gear can be expedited.

 

Note this is written in a hurry so better than nothing. Nev

 

 

[SDQDI]

But how do CASA do/force all that nev? There has to be some limitations brought in.

 

I have been thinking about it a little more and can't see why 19 reg couldn't be exempted from this. After all they won't be used for training unless the owner builder is being trained in it and they should be aloud to take that risk (going solo) in their own plane. And any passengers of 19 reg are/should be aware of the extra risks of homebuilts. 19 reg won't be going over any populated area so that doesn't affect them anyway.

 

But other than that I'm not sure what changes anyone else had in mind?

 

 

[DonRamsay]

Fact: there is a body of research work done by Ian Bent.

 

Fact: Jabiru themselves have not been doing nothing in terms of trying to eliminate problems but perhaps not enough.

 

Fact: CASA may not have legal force but can be very persuasive with threats. Even a proposed draft has had a major impact.

 

The key parties Jabiru, CASA and RA-Aus are in discussions and, to some extent, in negotiations.

 

Some good will come from this whole process but a great deal of unnecessary harm has already been done due to heavy handed action by CASA. I can't know whether CASA's severe actions came from exasperating frustration with Jabiru or from megalomania or incompetence or, as some suggested, a strong disinclination for Recreational Aviation to exist.

 

 

[kgwilson]

I agree that the harm has already been done by the heavy handed process from CASA. It was handled in a very pompous manner and then they tried to justify the process with a further 2 page explanation. This is the CASA culture in operation and may change once the new director comes on board but I imagine this will be slow and may be painful for some current staff who will resist any change. On the other hand CASA may continue to ignore the Forsyth report.

 

One thing I believe will be a certainty, is if the draft instrument is implemented without modification, there will be action (possibly legal challenges and/or a class action) taken by home builders in RA & GA as it effectively denies the builder the right to install an engine of their choice, a right which has existed since the 80s.