Dafydd Llewellyn

More power to your arm. If they're serious about putting in a new computer system, a sorting routine for accident / incident reports should not be too difficult a thing - but don't load poor Darren up with it.

You have a potential consumer protection organisation in the RAA - talk to them.

It has as far as I'm concerned; I've not been active on the website all that long. Please give me an indication of the thread on which you gave those data. I have to say, getting meaningful information is like getting blood out of a stone.

Well, if you are correct and 30% of 3110 are Jabiru motors, then we have 13 "engine problem" incidents & accidents in 933 aircraft with Jabiru engines. What time interval does this cover? As Skeptic points out, that still doesn't get a failure rate unless we have an average annual usage rate. Guessing some more, if the annual average utilisation were, say, 60 hours per year and those results were for one year, that works out at one engine problem for every 4300 hours. Once we get a failure rate, it's possible to make some sort of comparison. However if one supposes that the overall breakdown is something like 30% Jabiru, 60% Rotax and 10% other types, and fairly similar utilisation rates, one is looking at nearly four times the rate for Jabirus as for Rotaxes. Why has it taken so long for these numbers to emerge? I, for one, have been asking for them for quite a while. This is the sort of thing this forum needs to be doing. I'd still like to see a further breakdown into the type of engine problem - it's surely not asking too much to classify the failures according to what broke; e.g. crankshaft, valve, throughbolt, etcetera; that sort of factual information must also be available to RAA. The question of why it broke, is what needs the research - and I don't expect a body like RAA to be in a position to delve into that. This is the reason Ian Bent has been doing so much research, and why I am building an engine test cell. It's nice to know that the effort may be worth while. What are you lot doing about it? Complaining to Mummy may be about all RAA can reasonably do; but surely the rest of you can do a bit better than whinge?

Ta - that's a start, at last. A couple of points, if you can clarify the data: (1) The breakdown shows Overall Engine Problems (I assume this excludes fuel mismanagement) : Jabiru vs Rotax: 14 Jabiru vs 7 Rotax; which if I understand it, is made up of: Incidents: Rough Engine - 10 (4 Rotax, 6 Jabiru); Engine Failure - 7 (1 Rotax, 6 Jabiru), and Accidents: Engine Failure - 3 (2 Rotax, 1 Jabiru) I make the totals of that 13 Jabiru, 7 Rotax. (2) What are the total numbers of aircraft with Jabiru engines versus Rotax 4 - stroke engines? (3) What do we know about the causes of the engine problems (e.g. Through Bolts, valves, carby icing, etc)? (4) What are the figures for Rotax two-stroke and Rotax four-stroke, separately, please?

I'd have to agree. Can you supply a link to those statistics, please?

Obviously, everybody would like to invent a better safety pin. They still need to certificate (i) Their engines and (ii) The installation, before they can be used on other than VH experimental or -19 registered aircraft. As Don Ramsay pointed out, there are one or two 912 installations in Jabirus that have gone the CAR 35 route. That's not so easy to do under CASR 21 Subpart M; it's likely to require an STC under subpart D.

The trouble with that, is that the statistics are exactly what we have NOT seen. What we've seen is a small percentage of the Jabiru population - and we don't know how small - going down for reasons that have not as yet been defined; plus a known history of through-bolt failures - which were addressed by a Jabiru Service Bulletin and a free factory modification - which certain parties on this thread chose to ignore - and some exhaust valve failures. I not so long ago was asked to express a professional opinion on a 912 broken crankshaft, that resulted in a double fatality. None of these engines are as good as I'd like to see; but all the arm-waving and shouting isn't going to fix that. It can't be fixed until the research has been done to identify the real causes. Ian Bent has done an enormous amount of research, and is I believe pretty much on top of the causes, and what can be done to fix them; and if you own a -19 aircraft, or a VH experimental, that uses a Jab engine, it's worth contacting him. His fixes won't become available for other categories until they achieve the necessary CASA approvals - and work is proceeding on that. Jabiru cannot be expected to endorse these modifications until they do achieve CASA approval; that will be the time for people to start jumping around. If somebody wants to move faster than this process, go to it - but the message is, put up or shut up.

Certainly, a lot of hot air. Some of it going into the carburettor might help.

No, Pal, it doesn't. For a -19 aeroplane, or VH experimental, CASA approval is not necessary. If you have a -19 aeroplane, you can use Ian Bent's modifications, OR Rotec, OR your home-grown option, OR any other thing you like. I'm doing that with a 582 for that matter. Go do your own thing by all means, and THEN tell us about it. That's why we have the experimental provisions in CASR 21.191 thru 21.195, as explained in CASA AC 21.10. For anything else, CASA approval IS necessary.

Well, I have better things to do than trade insults on this forum. Did none of you notice that the engine in the photo I posted is fitted with one of Ian Bent's alternators? The problem (if there is one, that has not been positively demonstrated, despite all the assertions) won't be fixed by blather; it needs actual research. That photo shows that research is happening. With a bit of luck, it may show how to improve the margins of these engines; but just setting up to do the research is a major exercise. If somebody has a bright idea, they need to get off their backsides and prove it; and then push it through the process of CASA approval. Rotec has gone part way; but that is not sufficient. In the meantime, I agree totally with Rick-P.

East-West Airlines management's lawyer tried to apply their notion of what a contractor should carry by indemnity to me, in regard to the design contracting I did for them over the modifications to the Laser Airborne Depth Sounder F-27, VH-EWP; I simply pointed out that they needed me more than I needed them, and that topic was dropped. The aircraft reached honourable retirement a couple of years ago. The scarcity of aeronautical engineers had its uses, as far as I was concerned.

Thanks, Turbs. Well worth spelling that out for RAA members on this website. Don't know about the availability of public liability insurance for professional aeronautical engineers; it was hardly relevant under the QLD Professional Engineers Act. The public didn't beat a physical path to my door; it was all done by email and/or FAX. If there was physical presence needed, I went to the client, not vice-versa. I live on a very out-of-the-way rural property. For any aircraft, one needs insurance against the strict liability of the Damage by Aircraft Act (federal) which covers public liability to persons on the ground; and, I think, a public liability cover for other airspace users. Re 4.01, the RAA manuals have effect solely as a condition for the exemptions granted to RAA registered aircraft, in CAO 95.55 - so there is no way they can extend to non-RAA aircraft. That said, the normal regulatory requirement to get prior permission to use a private airfield, should bring to light any operations manager's existence, and simple courtesy should apply, if no more serious consideration does. Our "home field" is our own private strip, and it's definitely not a training field. We may fly-in to other fields, which will normally be gliding fields; but mostly we plan to go on safari with the aircraft on its trailer, simply for the convenience of having wheels, so we'd get whatever briefing there may be before we commit aviation at any site.

If you have insurance your insurer handles all that, but don't kid yourself that you can minimise your assets and get away with it. Two young guys with a very old panel van towing a very old car with a rope which was under specification for breaking strain are currently in the process of doing 6 1/2 years, and as far as I can find that was Australia's first mechanical specification case. I looked for it a couple of weeks ago and couldn't find it, but if I do I'll post it. That has to be a criminal penalty, not a civil one, n'est-ce pas?

David, you're 100% right. I've operated that way all my life, except between 1991 and 2001, when I was trapped by the QLD Act. The premiums I paid during that time were a dead loss. However, to be a "man of straw" and make it stick, you have to have been in that situation for quite a few years. Bill Whitney made no bones about it - he had a placard on his wall, stating that he did not carry insurance. Didn't stop any of his clients.

Neither. QLD has a Professional Engineers Act, and it required one to carry insurance. Out of the blue, all the aeronautical engineers registered in QLD were notified that their cover would not be renewed; I think the underwriters perceived too great a risk. The QLD Act had to be revised. I've never had a claim in my 35 years as a CASA design signatory, or my almost 50 years as a professional engineer. Same thing affects suppliers; there are many products that people will not sell if they know it's for use on an aircraft. G. James aluminium used to make the extrusions for lift struts for Australian aircraft manufacturers; they stopped on the instructions of their underwriters. Now Jabiru get their extrusions from India, I think. The fact that lift-struts are 100% proof-tested made no difference to the underwriters. The simple fact is that carrying insurance makes you a target - and you do not get your day in court, the insurer decides. One of my CAR 35 acquaintances had professional indemnity insurance; he was asked to approve the design of the seat that had been built for the Bandierante, by the Australian importers. He performed the structural tests required by FAR 23.561 - which was the applicable design standard; and it passed, so under CAR 35 he had to approve it. However, a fat fool getting into the aircraft caught his foot on the leg of the seat in front, and came down heavily on the centre seat-belt attachment, injuring his coccxyx. Being a smart fool and an insurance agent, he sued my friend for $25,000. The insurer naturally decided to settle, so my friend had to pay the $15,000 excess, despite having an unassailable defence in the wording of CAR 35. AND his premium was doubled - so he retired. He was a considerable loss to Australian aviation - one of the best engineers I've ever known. As it stands, the lawyers use contingency fee billing and the underwriters simply add what their actuarial calculations show is necessary to the premiums, and between the two, it's an unholy racket - tho I very much doubt anybody would get anywhere trying to prove any collusion; after all, what lawyer would represent you?

Did that 25 years ago.

Here we go again. Ta Ta

Professional liability insurance stopped being available for aeronautical engineers around 2001.

Ah - why didn't you say that the first time? The certification basis for the Jabiru 2200 is JAR 22H. The same certification basis was used for the Rotax 912 A series. It's au fond, a European standard for motor-glider engines - which was deemed appropriate for other recreational aeroplanes. The standard for Lycomings etc, is FAR Part 33; and this standard also is used for the Rotax 912F and S series. JAR 22H is very similar to FAR 33 except that the endurance run is 50 hours, versus 150 hours for FAR 33. However, JAR 22H makes it much easier for the manufacturer to use commercially-available components - whereas FAR 33 build requirements mean the manufacturer has to have traceability practically back to the ore from which the metal was smelted.

Thanks, David. If the installation detail design changes in a type-certificated aircraft, the cooling tests are required to be re-done. Jabiru builds its certificated aircraft under a CASA Production Certificate; and the issue of "Conformity" - i.e. making each one in strict compliance with the Type Design - is something CASA polices assiduously, at least now they have come to grips with Part 21, and set up a manufacturing QA branch i.e. since about 2008 or so. LSA models can be modified with much less formality - which makes that option much more attractive to a manufacturer - so they should not be mentioned in the same breath as certificated models; they are chalk and cheese. Overall, I agree with you that the cooling system can be improved. I doubt there is any designer who considers his design perfect; the problem is when to decide to stop fiddling with it. Type certification is usually that point. The suitability of instruments for their purpose is not a subject that arises in certification, certainly under the relaxed standards for recreational aircraft; perhaps it should. However, cost comes into that to a considerable degree; the cost of TSO'ed CHT instrument is probably about ten times that of a VDO commercial-grade instrument; multiply that by all the instruments in the panel, and you have a substantial increase in cost. Making the safest aircraft in the World achieves nothing if nobody buys it. You all accept low-grade Chinese altimeters and airspeed indicators. Is the Jabiru any different to the rest of its competition in that regard? The Blanik has military-standard instruments, which is one of the reasons I like it. But people are happy to buy gliders with the cheapest instruments available, because they cost less. The plain truth is that the market has to require a common standard across the board, or no manufacturer can afford to supply anything but the lowest common denominator. You wanted cheaper aeroplanes - and you got them. The Jab is amazing value for its price. Make up your B minds!

I'm not claiming that GFA procedures are cutting edge, any more than GAAP is; the bit I object to is making the individual liable for any perceived shortcoming in the procedures. Following the procedures and keeping your eyes open should be all that duty of care requires. There's a parallel, here; the wording of CAR 35 in relation to the approval of aircraft modifications was to the effect that if CASA or the Authorised Person was satisfied that the design of the modification complied with (the appropriate) aircraft design standard in force under the regulations, the CASA or the A.P. MUST approve the modification. In other words, neither CASA nor the A.P. was held responsible for what the design standard did or did not contain; and the design standards are put in place by Federal parliament. This provided good safety, and limited liability. It satisfied the duty of care. However, it came to an end in June 2011, and was replaced by CASR 21 subpart M, which goes further - it requires the A.P. to certify that the design is suitable for its intended purpose - which in effect makes each A.P. responsible for the deficiencies (as may be perceived by a Court) of the design standard - which is a formula for anarchy and chaos, in the fullness of time. I refused to have my design authority automatically transferred to the new system, for that reason. As a result of this change in the regulations, CAR 35 engineers are retiring as fast as they can afford to; and the cost of approvals has quadrupled. The effect on overall aviation safety has yet to become clear; by the time it does, the persons responsible for this change will have long gone. The effect of unbounded Duty of Care will inevitably be to destroy private aviation. I don't regard that as a desirable outcome, but doubtless the airlines do. If I were 20 years younger, I'd consider migrating to New Zealand, they seem to have retained their sanity rather better.

Um - I'm still somewhat in the dark. Every GA aircraft has its maintenance system identified in the Log Book Statement - on the first page of its log book. If it has a Lycoming engine, the Log Book Statement will normally specify the appropriate Lycoming maintenance manual. If it's a VH-registered Jabiru, it will specify the appropriate Jabiru maintenance manual. The specification of these in the Log Book Statement makes them mandatory. An owner or operator can apply to CASA to alter or vary the maintenance system; fleet operators often develop their own maintenance system. I have no idea how RAA handles that - or even if it does address it at all. Does that answer your question?

A Gliding club duty pilot's function is mainly to make sure the strip is clear for a glider in the circuit, and if the club uses winch launching, hold a launch if there's another aircraft anywhere near the zone used by the winch cable - and it's necessary, since in general, gliders can't go around. So he will keep an eye and an ear for incoming gliders, and hold a launch or order a stationary glider to be moved off the runway, as necessary. All that is entirely sensible and logical, and an obvious duty of care. But it does NOT extend to directing incoming gliders. I can see that if there are a number of RAA aircraft all using the same field, some form of ground marshalling could be necessary. However, the old "all-over field" procedure that was in use at Moorabbin mainly resulted in a silent tower; the tower sprang into action if somebody was obviously in trouble, and held all takeoffs and ordered all other aircraft in the circuit to continue to fly the circuit at 1000 feet, until the excitement was over. The way the tower operated at Camden, with mixed gliding and power operations, was (and no doubt still is) an object lesson - but the Camden controllers are VERY experienced professionals. I would dread to see what a hash an amateur RAA controller could make of something like that. So my point is, that the GAAP procedure is something that is drummed into every GA pilot's head, and at non-towered fields it works pretty well - so long as everybody can see everybody else. That can be very difficult if somebody's inbound, out of the sunset; and in a slow aircraft, you need eyes in the back of your head. The gliding world's approach to this is FLARM; but unless everybody has one and uses it, it's of little practical use.

The principle of interrupted fins was used on the Wright R 1820 and 3350 cylinder barrels, using stamped aluminium-sheet fins pressed or clipped onto the barrel. It was NOT used on the cylinder heads, which retained the classical "Pompadour" fin style. You do not find this sort of interrupted finning on a Lycoming or a Continental engine, which run around 50 horsepower per cylinder. Nor was it used by Pratt & Whitney, BMW, Bristol, etc. I think the development of air-cooled aircraft engine cylinders up to around 200 horsepower per cylinder, is a rather more appropriate datum for an aero engine, than motorcycle practice. The Jab engine is running 20 HP per cylinder, so it's making rather conservative use of this established practice. The merit or otherwise of the finning style depends on many factors, but the main one is how the overall airflow for cooling is to be managed. Normal pressure-cowled aircraft practice, is to recover the dynamic pressure from the speed of the airflow relative to the aircraft, in a duct or chamber on one side of the cylinders, and use that to force the flow between the cylinders, aided by whatever depression can be provided by the cowl outlet. With horizontally-opposed or in-line engine layout, that involves turning the flow through 90 degrees; with a radial, no turn is necessary. The form of cylinder-head finning you describe seems more appropriate to uncowled cylinders, i.e. 1920 aero-engine practice. Things have moved on from there. The form of the cooling provisions in the test cell is a consequence of the form of finning airflow adopted by the engine designer, not the cause of it. Let's see some test cell results for your cooling concepts, Rex? Preferable results witnessed by CASA.