Dafydd Llewellyn

The wheels float; the seat cushions float. Very curious there's no debris . . .

Ganagobie, itn't it?

True - but it affects the resale value.

Gliders have gone to extremes; and as in any composite airframe, it depends on just how they are put together. They can be very, very good, or they can be horrid - and you cannot tell which by looking at them. The early foam-filled wing Jabirus are remarkably good airframes from a structural standpoint. The later Jab types with the fuel in the wings have better handling and better performance, as well as better general utility - but I do not know anything about their ultimate durability. Of the Jab types, I liked the J 160C a lot; but if I had one now, I'd put a CAMit engine in it. You have to respect the glass undercarriage legs. Not really paddock aeroplanes, however, even with the big wheel options. I tend to be very wary of GRP gliders that were built with the main spar cap roving bands inside the skin sandwich, and which had a spar web that was connected to the skins by bog and good luck, at wing assembly. That joint is completely un-inspectable; and if it fails, you ain't got a wing. However, they do not seem to be falling out of the sky in any quantity - yet. Nevertheless, they have become aeronautical "white goods" and they are useless for anything except exactly what they were designed for. They are essentially "throw-away" aircraft, not designed to be maintained. Nobody is building anything of the ilk of a K13 any more. So if you want to spend $120 K or so in order to fly gliding competitions furiously for five years or so, and then throw it away, modern plastic fantastic gliders are just that - fantastic. Personally, that kind of flying doesn't appeal to me any more. For my opinion on RAA aircraft generally, see my thread Caveat Emptor on this site. They are almost all built to watered-down design standards - the ones certificated to JAR-VLA or higher are the best in this regard; you can find out which they are by downloading their Type certificate Data Sheets from their certificating authority's website. I consider the advent of LSA as potentially de-stabilising for the whole industry, because the LSA rules are a recipe for regulation by litigation. There are too many players in the market, and the shake-out will be bad for a fair percentage of owners; I would not touch one myself. Also, they try to be both trainers and useful personal aircraft - and that's really a contradiction of terms; for a trainer, the mission is to fly the aircraft. For a useful personal aircraft, the mission is to fly the mission - the aircraft should damn near fly itself. No aircraft can be good at both these requirements; they are diametrically opposite. So what we have are neither fish nor fowl.

Well, you're not alone on that, I suspect. But if this thread is to serve any useful purpose by indicating to manufacturers what the market wants, then we need to tell them.

Yes, well the PA28-140 that I had, had 6000 hours of training on it when I bought it. Its main problem was that it let the rain in, so the carpets were perpetually saturated - so I had to strip all that out and do some corrosion repairs. Piper's build quality was not good. The Blanik I'm modifying has 3076 hours - so its known safe life after the mod. will be just under 9000 hours. I'd not want to get into a Savannah (or damn near any recreational aeroplane, especially one with cantilever wings) with anything like those hours. The philosophy of recreational aeroplanes in regard to fatigue life, is that when they start falling out of the sky, the authorities will write ADs for them. Sort of like shutting the gate after the horse has departed. You're probably a lot safer in one that has a strut-braced wing - provided the strut itself and its load path through the bottom of the fuselage is properly engineered. Do keep a watchful eye on the lift strut load path.

That'd be a Bergfalke 4; I never had the opportunity to fly one - only the Berg III, which handles like a truck compared to the Blanik.

Yes, the Savannah is one possibility - tho I can't say I'm impressed by the quality of the engineering in its design. The constraint of 600 Kg does mean that sort of aircraft has to be very lightly built. Given what's around, it's one of the "least worst" options. What's its fatigue life? (rhetorical question). I know what the safe life of our Blanik is, and how much it is reduced when the engine goes on it. The problem with the weight limitations of recreational aircraft is that they HAVE to be built down to a weight. The Jabiru airframe is a remarkable achievement, given that constraint. If I were limited to what's on the market, and 20 years younger, I'd probably look for a Maule M5-180; but that's not a recreational aircraft. Yes, it has a fabric-covered fuselage - but as I have a hangar, I could live with that for its other merits. However I couldn't maintain it myself, whereas I can maintain the Blanik myself, so it would be outside my current means.

Well, I happen to own an STC to extend their lives from 4000 hours to 12,000 hours, so that's not a problem - tho it IS a cost to be considered. Look up STC SVA-542 on the CASA website.

I wasn't trying to point to any particular type; the question was, "what do people want in a recreational aircraft?" I think the answer must depend on a number of peripheral matters, which will differ greatly from one person to another. For example, do you have hangarage available? I happen (by choice) to live on a rural block & have my own (short) airstrip & a hangar. Most people do not have that; and so their choice is likely to be constrained. If you are paying for hangarage, folding wings are a considerable advantage. If you have to leave it tied down in the open - as I did when I had a PA 28-140, there are a different set of constraints. Cost is a major consideration for everybody, but it's affected by things like the availability of maintenance facilities, insurance, fuel efficiency, etc, which will have different importance for different people. So, really, it's a silly question. Do you want to use the aircraft mainly to go places - i.e. do you want to get there quickly - or do you want to really enjoy looking at the countryside? Are you simply obsessed with speed? (That gets boring after a while). So it's much more practical to ask, "what do people NOT want in a recreational aircraft?" Here's my list: I don't want open cockpits. I don't want fabric covering. I don't want an aircraft whose fatigue life is completely unknown. I don't want a flimsy, "Reynolds Wrap" special, held together with pop rivets. I don't want an aircraft whose GC limits and flight envelope limits are unknown. I don't want an aircraft that is likely to overturn in an emergency landing, from which escape is then impossible. I don't want an aircraft that has marginal stability in any normal flight condition; or that has poor control harmonisation. I don't want an aircraft that is incapable of routinely operating from a croppie strip or a paddock. I don't want a nosewheel aircraft that has either a small nosewheel or inadequate propeller clearance; I prefer taildraggers for those reasons. I don't want a nosewheel aircraft whose crosswind capability is limited by "wheelbarrowing". That's ten "don't wants", for starters. I could go on. What's your list?

Thanks, but I'm doing a motorized Blanik, which does it all better than the Savannah (except for take-off distance, I suspect - but not by much)

I couldn't agree more, Andy; CASA relies on people not being able to afford to fight them in court. It's very far from justice.

I must say, I suspect the correct title of this thread should have been "What do people NOT want in a recreational aircraft?" A couple of observations: 1. A stall speed claim under 35 knots almost always means the airspeed system has enormous error. Anybody who suffers from the delusion that their aircraft really stalls that slow, needs to read CASA AC 21.40 (can't give the link; it's on the CASA website, www.casa.gov.au under "CASR 1998 - Part 21). A Blanik stalls below 33 kts CAS with full flap - but it has 19.15 square metres of wing, and a max weight of 500 Kg, and fowler flaps. That's 26 Kg / square metre wing loading. You got 25 knots stall on 40 Kg/sq M? Horse shit! Adding VGs and leading-edge slats can reduce the stall speed by about 6% IF the elevator authority is sufficient (usually it isn't). 2. If it has to live out in the open, metal is the only practical choice - but the very thin gauges on recreational aircraft are very prone to hail damage. 3. A fast single-engine aircraft is nice - until you have to put it down in a paddock. Small wheels mean less drag - until you have to put it down in a paddock. A low wing is nice for field-of-view - but if it overturns when you have to put it down in a paddock, can you get out of it? 4. The question is not whether you will have to put it down in a paddock, but when. I've done so on several occasions in my PA 28-140, not because of engine problems, and I chose it because it had a nose wheel the same size as the main wheels, (600 x 6) and a generally robust undercarriage - and you could get out of it in the event of an overturn. If you use a single-engine aircraft to travel cross-country, knowing it's suitable for a paddock landing is a significant safety advantage. If you choose an aircraft that is fundamentally unsuitable for off-airfield landing, it better have a very reliable engine. 5. A claimed cruise speed higher than about 2.5 times the stall speed, generally ignores the need to prevent the wings from clapping hands due to an up-gust. This is far too prevalent; many importers are unconscionable about their cruise speed claims. A clean aircraft may well be capable of flying faster than 2.5 times the stall speed, but do you understand the safety issues in doing so? Most recreational aircraft design standards do not require the manufacturer to declare a "maximum structural cruise" or a "Maximum rough air" speed; but it's usually around 2.5 times the stall speed. So if it flies fast, it will also land fast. I can't offhand think of anything more potentially dangerous than a Lightning Bug with an AMW engine, if you fly it beyond glide range of a bitumen runway. . . . 6. If you choose the option of a paddock-capable aircraft, consider the aspect of protection against wires coming through the windscreen. Paddocks have wires. 7. The slowest aircraft is still about twice as fast point-to-point as the fastest you can get there by car in the real world. Yes, a PA 28-140 feels as slow as a wet week, at 5000 feet - but that's an illusion. What you are seeing is that the World is a fairly big place; in a car, you can likely see about 10 Km. In an aircraft, you can see 100 Km - so of course it feels slow - but it ain't, really.

Don, just to set the record straight: Elimination of "regulation by exemption" was a major driver of the Review of regulations 1996, set up by John Sharpe. Dick Smith first pointed the finger at it in his book "Two years in the Aviation Hall of Doom", and it was an identified aim. I was a member of the steering committee of that review, for two years; in case people have forgotten, it's still happening, though a lot of the original concepts have been distorted. Getting rid of "regulation by exemption" has been on CASA's agenda now for at least two decades - and things are slowly moving that way. The principal area of "regulation by exemption" is of course the 95 series Civil Aviation Orders, which are ALL exemption-based; and I'd venture to suggest that had the change been more precipitous it would have been a catastrophic shock for the various recreational aviation sectors, whose members seem allergic to reading the regulations, let alone observing them. The change essentially involves re-writing the regulations so that instead of saying "You can't do that, unless . . ." they say "You can do that, provided . . ." . Under the old system, exemptions were the only way to have an alternative to main-stream aviation. The attempt represented by Part 103, was in my view a very mistaken approach; it was in effect a straight-jacket that would have strangled development of recreational aviation within a decade or two. It was attractive at the time because it appeared to provide room for growth - but it was essentially a straight-jacket that was two sizes too large at the time, so that appearance was illusory. Recreational aviation is not going to stand still; the RAA mis-management schemozzle has set it back in Australia for a while; but it must either grow or die; it cannot remain static. The advent of the RPL is in fact a doorway - for those that choose to use it - into the larger aviation world, from the recreational aviation world. It's an opportunity, not a threat. RAA needs to work out how to use it as such. Yes, the AAAA submission was excellent. Our old regulations are piecemeal and ad-hoc. It's instructive to look at FAR Part 91; it manages to bring all the aspects of recreational aviation as they exist in the U.S.A. into the same arena as GA, without stomping on the activities - tho it makes organisations such as RAA irrelevant; and it's short & sweet compared to the CASA attempt at a Part 91. The New Zealanders have been smart enough to adopt it, without trying to "improve" it. We should be that smart.

See http://www.recreationalflying.com/threads/caveat-emptor.67826/

Could you get a weekend casual job with your local motor wrecker? That will teach you basic spanner work faster than anything else I can think of. After a couple of weekends at that, do what Downunder recommends; but first, look through the overhaul manuals at your local newsagent, and pick a make & model for which good how to do it instructions are in the manual. Start with an older model engine that has a carburettor and 2 valves per cylinder; modern engines have so many bells & whistles on them that it's a bit bewildering for a newbie. If there's a Tech. college course on DIY car maintenance, that would likely be a good place to start. That will get you a pretty fair basic introduction to engines - at least, liquid-cooled ones. Aircraft materials and hardware are quite a bit different to the sort of thing Bunnings etc sell; that's something to pick up after you get used to grease under the fingernails & basic mechanical principles. I started with model planes & lawnmowers, too. Overhauling something like a Briggs & Stratton fire pump motor will teach you quite a lot - and the pieces are not so heavy if you drop them on your toe . . .

No, Nev - If you read the description to which John Brandon provided the link, there's no bending moment on the crank - or more precisely, the gearbox output shaft - because the blade/counterweight assembly is hinged there. A hinge won't tranfer a bending moment; that's what it's for, after all. There is neither a bending moment due to the thrust being from a single blade, nor from propeller "P" effect, nor from gyroscopic loads. The gearbox output shaft has a holiday compared to the normal setup. The blade drag force causes a run-out of about 4 mm at the propeller hub - i.e. the propeller runs about 2 mm offset, because that amount of offset generates a centrifugal load that balances the in-plane force on the blade; and yes, the engine mount has to be designed for that, which means the normal method of four rubber blocks on the four bolts at the bottom of the crankcase is quite unsuitable. It won't trouble the carburettor because it won't be mounted on the engine; I'm going to use a CD carbie (Bing type 64) mounted on the pylon structure, underneath the engine and feeding the rotary valve via a Y-branch that is flexible connected at both ends; the motion on the rubbers is no worse than for the usual cantilever mounting. The Rotax 2-cylinder engines throw their propellers around in a circle anyway, due to the residual out-of-balance of the two cylinders; but because the engine RPM is so high, the amplitude is small. I learned that back in the -80s with a redrive I designed for a Blanik 532 installation that had a heavy MT electric-feathering prop. on it (26 lbs). It showed up as heavy fretting wear on the redrive output shaft under the outboard bearing.

Good question. However, divide the number of RAA registered aircraft by 250 and you have roughly the number of renewals the TM has to get through in a day. That may explain, in part, why the job was not done as thoroughly as it should have been, in the past. In effect, RAA has been using the TM and registration renewals to make money, NOT for what it needs to do to serve the members. It's still trying to do so, as far as I can see. So the RAA system is wrong, and needs to be fixed. You're the members, get on your hind legs and do summat about it.

Right on all counts - except I think RAA has been negligent; the reason you give explains why, but it's not an excuse. Pursuing that is not likely to be worth the effort unfortunately; but it should be recognised that this is the case. Equally, the previous owners have also been negligent. Having said that, may I respectfully point out that the "drifting" behaviour of both RAA airworthiness status and of RAA pilot certificate endorsements would not have occurred if AUF/RAA had not set out to "simplify" the whole business by eliminating both the Certificate of Airworthiness and the pilot licence from its world? If you all want this unsatisfactory situation to not recur in the future, IMHO the best way to achieve that would be to insist that RAA, when it gets to the end of the present registration muddle, issues a certificate of airworthiness for each registered aircraft? Then you will have a record the you can produce at need. Similarly, the pilot certificate should specify all your endorsements. This whole problem has arisen because RAA has been more interested in using aircraft registration and pilot certificate renewals as a source of income, rather than as records of the safety status of the aircraft and the pilot. Gliders have Certificates of Airworthiness. They are a one-time issue; what you pay for is the paperwork for the mandatory annual inspection. The inspection results in a Maintenance Release. The record of that goes back to GFA, who keep it on the aircraft file. If GFA can do this, RAA has no excuse. I'm overhauling a 40 year old glider; all its paperwork is in order, as it should be. Roll on, the RPL; it will force proper record-keeping. The situation for aircraft "accepted" under CAO 95.25 is rather murky; they were not certificated, but were "accepted" on the basis of a comprehensive report from a CAR 35 engineer (who thereby took on an open-ended liability). That acceptance basis implies that a modification to such an aircraft can in principle, also be approved by a CAR 35 engineer - if he's willing to accept the liability (which is much greater than what he accepted in approving a mod. for a certificated aircraft; all he has to do for that is to ensure it complies with the original design standard). When I was an active CAR 35 engineer, I did several such approvals - so some owners did do it correctly. There is at present, to my knowledge, no legal basis under which CAO 95.25 aircraft could be issued with a C of A; so for them an alternative piece of paper needs to be created. CAR 35 engineers no longer exist; they are now CASR 21.M engineers, and they operate under more restrictive constraints; so it's a bit late to be trying to catch-up with approvals that should have been made decades ago - but perhaps not yet impossible. However CASR 21M Authorised Persons must become CASR 21.J Approved Design Organisations within the next four years, and I doubt any of those will touch a 95.25 aircraft, so don't sit around sucking your thumbs. The overall message is that those aircraft have really seen their day, and as far as the system is concerned, are overdue to be scrapped. Sorry, but them's the facts.

Normally, correctly-given airworthiness approvals remain valid indefinitely. If CASA has an issue with one, this normally surfaces early in the piece.

Yes, there are a number of variations on the theme around. Single-bladers seem to be used mostly on retracting engine types, to minimise the size of the cut-out needed in the fuselage. Two-bladers are of course common on rubber-band powered model aircraft; I built one as a child. The novelty lies not so much in the single-blade propeller, as in the form of engine mounting necessary to allow it to self-balance for the blade drag that acts in the plane of rotation.

Yes. Polyurethane is best.

Ask somebody who has the necessary approval before you make that assumption. I retired out of that game two years ago, so I'm not fully current with the constraints.

Yes, of course - trouble is, it's a two-hour drive to & from Brisbane airport. And I usually need wheels at the other end, which is often Mittagong or Hervey Bay. Look at the complete journey, not just the bit of it between airport lounges.

No, it's a public debate; anybody can oppose it if they wish. I have just as much right to express my opinion as you do to yours.