Dafydd Llewellyn

CAMit could also lift a whole lot of liability burdens off Rod's shoulders, once their mod. gets a formal approval. If somebody else gets an STC to install a CAMit engine, Rod can simply sell them an airframe. OR he could offer to install the CAMit engine that is purchased by the customer directly from CAMit. He cannot reasonably be expected to do that until the CAMit mods have an appropriate formal approval under the regulations. As I said, people are working on that.

It also achieves compliance with the law. You want to change that, go change the law. Exp. Cat and CAO 95.55.1.5 provide an alternative. It's one or the other.

All the Jabiru 2200s used in training schools are, I think you will find, on either Type Certificated airframes or LSA certified airframes. Every factory-built Jabiru up to the J160C was Type certificated; after that the LSA rule came in and Jabiru was in a position to make use of it, so they did. The Jabiru 2200 J and 2200C are type certificated; I do not know whether they have other models that are self-certified under the LSA rules. The advantage in using a TC'd engine on an experimental or CAO 95.55.1.5 aeroplane comes in two places - firstly, the hours required to be flown-off in a restricted area; secondly, the operating limitations that will subsequently be placed on the aircraft. I don't know how RAA handle those matters, but see the appendices to CASA AC 21.10. I'm not familiar with how RAA handles the use of non-approved parts or non-approved aircraft modifications; this may be one of the aspects that is quite unsatisfactorily regulated, as a consequence of the RAA not using Certificates of Airworthiness. That's Darren Barnfield's problem, and I do not envy him. But in regard to a VH aeroplane, look up CAR 42U. I was not trying to be judgemental in regard to Jabiru; merely to point out the legal consequences. Rod stated them correctly, IMHO.

I would advise readers to keep the basics in mind: 1. If you modify a type-certificated engine, propeller or aircraft IN ANY WAY (and that means interfering with what is in its parts catalog, or by altering its adjustments from what they are supposed to be) WITHOUT HAVING A FORMAL APPROVAL TO DO SO - which means, you must have approved data as defined in CAR 2A - OR you allow the work to be performed by anybody who does not have a maintenance authority that covers the work, your insurance will be null & void, unless you have your insurer's agreement to cover the modified product (LOL). 2. The approval can take a number of forms: It can be a substitute part that is approved under a PMA (American) or APMA (Australian). It can be a major modification that is approved via a Supplemental Type Certificate. It can be a minor modification that is approved via an Engineering Order under CASR subpart 21.M. It can be a modification that is mandated by an Airworthiness Directive. It can be a modification that is allowed by the manufacturer under a field service document such as a Service Bulletin or Service Letter. These are all set out, in order of precedence, in CAR 2A. 3. If you perform an unapproved modification to a type certificated product used in a type certificated aircraft, you will have committed a criminal offence under the regulations. It's no defence whatever to grumble about lack of support from the manufacturer; the foregoing stands regardless. If the engine or propeller is used in an experimental aircraft, rather than in a TC'd aircraft, modifying it without approved data voids its status as a certificated component; this is likely to void any operating conditions and also to void the insurance - but so far as I am aware, it's not a criminal offence in its own right, unless perhaps you fail to make the situation known to the responsible authority. I am not aware of any formal approval for the fitment of the ROTEC water-cooled heads, or for that matter CAMit components, to a certificated Jabiru engine. At present, these components can only be fitted to engines used in an experimental (including, I suggest, CAO 95.55.1.5) aircraft - but you'd better let both RAA and your insurer know about it. I do know that a lot of effort is going into achieving an appropriate approval status for CAMit mods, but it will be a little longer before that reaches fruitition. In the meantime, they can be used where such formal approval is not required. If I had a 95.55.1.5 aircraft, I'd certainly use them. What Rod Stiff has said is quite correct (with the possible exception of the bit about surrendering Lycoming data plates - tho Rod may have more recent knowledge of that than I do). Whatever one's views may be about his products, they do not alter the validity of what he has said.

I was referring to the amendment Act 1988. I'm not entering into a debate on that aspect; I would point out that the Jabiru 2200 engine has a Type Certificate issued by CASA; you can work out for yourself what that means under the TPA. What constitutes that engine is defined by its Type Design (See CASR 21.031). The best available quide to that is the parts catalog. I don't think cylinder head thermocouples are things you will find listed in the part catalog, if so adding additional sensors of that nature would not constitute a modification to the engine. They may, however, constitute a modification to the aircraft - unless they are supplementary to what is supplied by Jabiru, rather than a replacement for it. RAA registration seems to confuse LSA and TC aircraft, so it's not - as far as I can see - a reliable guide to which aircraft require mods to be approved under CASR 21.M and which require them to be approved by the manufacturer. However you seem to have a rather confused understanding about all this, so I suggest you research the subject. Or, as you suggest, stick to -19 aircraft.

I suggest you read the Trade Practices Act 1988.

No - firstly, I'm talking about a certificated ENGINE, not a certificated installation. Secondly, if you look at CASR 21.191, there are about ten experimental purposes, only one of which is educational. CAO 95.55.1.5 parallels only CASR 21.191(g).

Get real. If Jabiru give a public approval for the fitment of a CAMit engine into their LSA-certified aircraft, that means Jabiru would pick up the liability for something they do not control and have not designed. That's hardly a reasonable ask. However, when the CAMit package has an approval from CASA, that relieves Jabiru from liability for the engine. Until that happens, FFS stop complaining about Jabiru not accepting the CAMit mods.

You would call it a non-certificated engine. There are two types of engine used in experimental / -19 registered aircraft, and only two: Type-certificated and non-type-certificated.

If you modify a type-certificated engine, other than in accordance with approved data (See CARs 1988, regulation 2A) it is no longer a type certificated engine. The manufacturer can no longer be held liable for it, and its warranty will be void. So I would rather imagine that a pragmatic manufacturer might not actually mind that much if people persist in modifying his product; he will mind if he gets the bad press for the consequences. I'd not heard that bit of scuttlebut about Lycoming engines in experimental aircraft, however. Since even TC'd aircraft may need to be flown under an experimental certificate on occasion to get some modification approved (e.g. the installation of role equipment), and this does not result in Lycoming requiring the engine data plate to be removed, I doubt it's correct. Didn't happen whilst I was flying the Seabird Seeker on an exp. Cert, for its certification flight testing, either. If the aircraft is operating under normal GA rules, making an unapproved modification is a criminal offence. See CAR 42U.

An RAA -19 aircraft is the equivalent of a GA Experimental amateur-built aircraft; provided it meets the requirements of CAO 95.55.1.5 - i.e. the major portion rule, and the category stall speed limit, etc, YOU are in effect the designer. The fundamental principle of the experimental provisions in CASR Part 21 is 180 degrees opposite to the fundamental principle of all other aircraft; in regard to all other aircraft (ALL aircraft, prior to the introduction of CASR Part 21. 191 thru 21.195, in 1998) the fundamental principle is that CASA protects people from their own stupidity and ignorance. For aircraft that come under CASR 21.191 and CAO 95.55.1.5, the principle is voluntary acceptance of risk. If you want to understand this better, look at CASA AC 21.10. As George Markey was wont to say - you can make an experimental aircraft out of jelly and custard - CASA can't stop you. What they CAN do is decide who can fly it, where, and when. (Probably McMurdo Sound, in a blizzard, in that case). Presumably RAA can make similar constraints, tho I do not know if they have ever recognised their responsibility in this area. So this freedom comes with strings. Certificated aircraft have different strings, and LSA aircraft have yet another set of strings. A chaque un, son gout.

Look, I'll say it again - the weight increase IS NOT the result of some magical physical effect of the floats that somehow makes the aircraft stronger. It's either the result of the original designers deciding to put out a float version of the aircraft, which they justified by analysis and/or test, for a higher weight. If Cessna advertise the 172 as a four-place aircraft, their sales Dept. presumably would want the seaplane version to also be a four-place aircraft - and to have anything like the same disposable load, the MTOW would have to increase. Standards such as FAR 23 and CAR 3 had an upper weight limit of 12,500 lbs (5700 Kg) so there was no regulatory "lid" on the MTOW; Cessna could add some additional structure and a larger diameter fine-pitch propeller, or whatever it took. OR it's a subsequent modification, justified under the Supplemental Type certificate process, by either the OEM or a third party - probably the float manufacturer. Either way, any weight increase has to be justified as complying with the original certification design standard. When you come to the LSA rules, the MTOW the designer uses has to be pretty much the upper limit allowed by the category, or the aircraft will not be commercially competetive. The "lid" is set very restrictively, so the designer will inevitably be banging his head on it. So the writers of the rule decided to allow an extra 50 Kg for the designer to use, if he was designing a float version. It's for the DESIGNER to use, NOT something anybody can take advantage of by bunging floats onto an aircraft that was not originally designed for them. The STC process IS NOT AVAILABLE for LSA aircraft, because they don't have a TC in the first place, so no third party can come along afterwards and add a float kit to an LSA aircraft - it HAS to be built in to the original design. So the title of this thread is misleading - the MTOW of an LSA aircraft does NOT increase with floats - unless that was designed into the aircraft by its manufacturer. With a certificated aircraft, the STC process is available; and that's very likely the way most GA float conversions were approved.

I'm not the authoritative source of information on this; but my understanding is that if it has the Jabiru part number, it's not the revised CAMIT design. CAMIT makes Jabiru parts, to Jabiru's design, under Jabiru's Production certificate, which means - as I understand it - that only Jabiru can issue release notes for them. CAMIT has its own Production Certificate, but it's under CASR 21.133(2B), which means the parts made under that PC have to be ordered on a "one off" basis - that was how it was done for the Blanik life-extension parts kits. There is a lot to do to extend this to parts for general supply.

Not yet; I understand that considerable effort is happening to get the approval to do so.

Are you confusing the new CAMIT barrels with Jabiru barrels? The CAMIT barrels certainly do have larger through bolts, a thicker flange and a thicker barrel wall in the vicinity of the flange. Dunno about the "latest" Jabiru barrels - that engine cannot have had the new CAMIT barrels.

Well, not so surprising, because the LADS project (which I mentioned earlier) was done in Salisbury, SA - the best they could do for the LADS project was 401 alloy, which ain't good enough for cylinder heads. That's almost twenty years ago - but unless people are demanding something akin to cylinder head castings, how are they going to become familiar with those alloys, and the problems of casting deep cooling fins? - Go look at a Lycoming head. You're looking at closely-spaced fins of around 30:1 depth to thickness ratio. You want to see GOOD foundry technique? Go to France.

Were they aluminium or bronze? GMH built Gipsies for the Tiger Moths used for the Empire Pilot's Training Scheme; they were early Mk 1s, I think, with bronze heads - I had one, in my Auster Mk III. You're dead right about small production runs; CNC is much easier from a QA standpoint. Porosity is a major problem for any kind of cylinder head.

Nev, they could be made of unobtanium, but it cuts no ice unless they STC the engine for them.

They're water-cooled - so an entirely different ball game to a closely-finned air-cooled head. Has ROTEC obtained a supplemental type certificate for those heads?

Interesting - has he ever tried casting 242 alloy? I suspect it needs some sort of "impact moulding" technique to be sufficiently free of porosity in an air-cooled cylinder head; the fins on a Lycoming head are pretty formidable to cast. Most Australian foundries seem to use mainly silicon eutectic alloy, which runs like water and is barely stronger than Kraft cheese, or the occasional one that can manage 601 alloy, for wheels. I had some peripheral contact with a "difficult" casting for the Laser Airborne Depth Sounder, and the best anybody could do for that was 401, which is still well short of what is needed for a cylinder head that works at Lycoming-type temperatures. The wrought alloys are generally completely free from porosity, so they lend themselves well to billet machining - but that puts considerable constraint on the form of the cylinder fins. Take a good look at the finning on a Pratt & Whitney R1830, and ask your brother how one could do that. However, that's not the point of this thread; the point is that it is NOT the choice of crankcase material that is the issue with the Jabiru through-bolts. There are about six contributory factors, as far as I can see, and Ian Bent has done extensive research into all of them. The Devil is in the detail, and there are a whole bunch of relevant details. Ian can explain them better than I can.

As you can see from my earlier post, the data for 5083 (which was the material in Jabiru heads for a long time) do not go above 90 degrees farenheit. The data for 6061 go to 600 degrees farenheit, which is well above the maximum permissible head temperature. These data are from MIL-Handbook-5 ("Metallic materials for aerospace vehicle structures" which is jointly published by the FAA and the U.S. Dept of defense; it can be downloaded from the net, and is the definitive document for aircraft materials). So whilst I do not fully understand your question, the data in my previous post are all I have available. Lycoming & Continental cylinder heads are a quite different alloy, BTW. I do know that Rod Stiff started out with cast crankcases, but the rejection rate due to porosity was such that he had to abandon them; the Australian aluminium casting industry is not, it appears, capable of casting something like a Lycoming cylinder head.

Halon is permitted in aircraft, I think you will find, but how you can get hold of it I do not know; this is something I would suggest you ask CASA. Dry powder extinguishant is sudden death for a metal aircraft; I've seen a Metro written off because a mechanic used a dry powder extinguisher inside it to put out a minor fire in maintenance (a soda syphon would have done the job).

Maj, you've raised this issue before, and it is just as invalid now as it was then. Attached are the data for 5083 (the Jabiru crankcase material), 6061, and cast 355 alloy (which is what Lycoming and Continental use). At (say) 90F, the expansion coefficients (alpha in the graphs and the table) are: 5083: 13.2 x 10^-6 inches per inch per degree farenheit; 6061: 12.65 x 10^-6 inches per inch per degree farenheit; 355 : 12.4 x 10^-6 inches per inch per degree farenheit. Note that the values make no distinction whatever between wrought or cast forms. So the difference amounts to a bit less than 6.5% between 5083 and 355, with 6061 in between them. This hardly justifies your assertion.

Sensible question; I'm not familiar with the RAA training syllabus, but if it's the same as the old restricted PPL syllabus, you should, I suspect, have been taught how to use this. Essentially, it consists of using the ailerons and the rudder against one another - so-called "cross controls" - so the aircraft is tracking along the projected runway centreline, but with one wing down and the nose pointing off to the opposite side. This is sometimes called a "forward slip" (if people want to be pedantic). Used this way, it's a means of increasing the drag - by presenting the fuselage side area somewhat - which does much what dive brakes do for a glider. In a cross-wind, you use it differently; line the fuselage up with the runway centreline and keep it there with rudder, and lower the windward wing tip sufficiently to counter the lateral drift due to the crosswind component; you can hold this all the way to a touchdown on the upwind undercarriage leg - in a high-wing aircraft. Some caution is needed in a low-wing aircraft, or you may scrape a wingtip. That's the plus side. The negative side of the equation is that if you stall the aircraft with crossed controls, it will do its best to enter a spin. So you need to watch the speed like a hawk whilst doing this. Most pitot heads start to under-read at yaw angles exceeding about 10 or 12 degrees - so if you maintain the same indicated airspeed, the real airspeed will be higher than what you see - which means not much risk of stalling, but you may exceed the flap speed without being aware of it. I used to use slipping a lot when flying a Super Cub for glider towing - but after a while, the flap hinge brackets started to show cracks; the pitot error was the reason for that. So be careful about slipping with the flaps extended, unless the flap extension speed is at least (say) 15 knots higher than the approach speed. Also, if you hold the slip all the way to touch-down, it's important to arrive very, very gently - because a typical spring-leg undercarriage (or the pivoted undercarriage legs on Cubs or Austers etc) become dead rigid if the line of the resultant force at the wheel happens to pass through the point of attachment of the leg to the lower longeron. So there are some points to watch to use this technique safely; and there are some aircraft in which slipping is prohibited with the flaps extended - the DHC-1 for one. So read the fine print in the Flight manual.