Dieselten

Reading this thread - even with the large amount of good, sound technical knowledge and sheer practical common sense it contains - seems to me rather like arguing about how many angels can dance on the head of a pin. Dogma and doctrine, argued with the ferocity of wizened old clerics haggling over abstruse point of canon law. What I am not seeing - anywhere - is any suggestion that the torque on Jabiru through-bolts be periodically re-checked! Perhaps I am excessively stupid, naieve or just plain thick, but if these can loosen and cycle until they break, then checking them seems the blindingly obvious thing to do. And yet no-one appears to think this is worthwhile, least of all the factory that makes the thing in the first place. They tell us it is buttoned up and will run 2000 hours. Well, there is a steadily growing list of failures which constitutes evidence to the contrary. Do we have to lose lives before someone decides this might be a good idea? If the cause of through-bolt breakage is nuts loosening, allowing the bolts to begin cycling until they ultimately suffer a fatigue-fracture, then surely it makes perfect sense to re-check torque at regular intervals? Yet no-one seems to have suggested this. Jabiru glue the nuts on both ends with Loctite 620 and there is nothing in the service manual about re-checking the torque - ever. If the torque Jabiru uses is correct, then why glue both nuts on any given through-bolt? Are they holding the engine together with a torqued nut (and the pre-loaded through-bolt) or are they holding the engine together with Loctite 620? If the torque is correct then no adhesive should be required on one of the two nuts on any given through-bolt. If the torque is not correct then the Loctite 620 is merely masking the problem. Maybe Jabiru have to bite the bullet and introduce a timed through-bolt torque-check. Even the time and effort in removing the cylinder-heads and checking the torque on the lower through-bolts is far less than the inconvenience and expense of having an engine re-build. I have had so much grief from their engine on my aircraft that I will be getting a LAME to re-check the torque at 500 hours when I replace all the exhaust-valves (they won't even do 1000 hours). I'm a pragmatist. I need an engine that runs reliably, not one that breaks at random intervals because a bolt fails when the failure could be prevented by an extra bit of preventative maintenance which the manufacturer claims is not necessary. Theories about why these things fail is all very well. I want results. I've had a belly-full of the theory!

I quite understand Clive J's point-of-view. I am in the "unofficial/un-paid test-pilot" stage with my second-incarnation 2.2l Jabiru engine. To beat the first incarnation it merely has to do 675 hours without breaking through-bolts, burning out exhaust-valves, leaking oil like an blown-out oil-well, or cracking the base of a rear cylinder. My first Rotax 582 lasted longer and was still running sweetly when it went for a rebuild! Personal opinion follows:- If Jabiru abandoned making engines and just fitted Rotax 912/914 engines, they'd have to open another factory just to keep up with the demand for airframes. They wouldn't be able to make them fast enough, and within three years they'd have ten thousand airframes being hauled around by the little Austrian "engine that could" instead of the little Australian "engine that couldn't".

"Fly The Wing". Irrespective of whether you fly 3-axis or weight-shift. Bank left - turn left. Wing level- fly straight & level Bank right - turn right. Push bar forward - increases AoA, you fly slower. Pull bar back - AoA decreases, you fly faster. A wing doesn't know what sort of aeroplane it is attached to - it only knows how to make lift. Think - and fly - angle-of-bank and angle-of-attack. In a strong crosswind, land a trike directly into the wind, diagonally across the runway. Your groundspeed will be minimal, with zero sideways drift. You will probably need to apply power to get to the other side of the runway. Turn the crosswind into a headwind. Fly the wing, not hands, arms and feet. Make the wing go where it has to go and the rest of the aeroplane, be it a 747, an RV, an SR-71 or a trike, will go there with it. Fly the damn wing!

A Greenie decided to build a plane. Because aircraft are anathema to the Greens, he also decided to make it the stealthiest, quietest, most invisible airplane ever built, far more so then even the vaunted Skunk Works had ever produced. Clearly this would require some unique materials and methods of construction. Reluctant to use anything that required the sacrifice of a living thing, or involve the expenditure of any form of energy to produce (such as metal) he constructed it entirely from naturally-occurring materials which he found lying around. For the wings he used the unshakable scientific expertise and knowledge of the environmentalists. Although invisible, he felt this was so solid and strong it would lift anything. After all, everyone believes that science is always impartial and unchallengable. For the powerplant he decided to use hot-air, because it obviously worked so well in balloons. So he went to Canberra, where this material is present in unusual abundance. He found the primary source at Parliament House, and brought back an enormous quantity which, paradoxically, fitted inside a small shopping-bag. Whilst in Canberra he also found something even he realised he would need in order to get his airplane to fly - a huge quantity of spin for the propeller. Everywhere he went in Canberra he encountered spin in unbelievable quantities, so he returned from his trip to the nation's capital with two essentials for aviation - massive quantities of air, and something to spin his propeller. Because the airframe was so light, and the power of hot air and spin so powerful, the aircraft would easily carry over a hundred people with just a single engine. Maintenance costs would be minimal. For the fuselage and empennage he decided to use the invisible fabric of broken political promises. The invisibility of this material matched that of his chosen wing-material, so he felt he was really on his game when it came time to mate the wings to the fuselage. To join them he used the irrefutable logic of the Left, where one only has to say a thing is so and it automatically is, and has been for all measureable time. He simply said "let the wings be joined to the fuselage" and lo! it was so. Came the day when this environmentally-friendly, carbon-neutral, zero-emission wonder was to be unveiled to a waiting crowd of press, politicians, dignitaries and general hangers-on. The aircraft was covered in a cloth, laser-lights played against a background of fog, mood-music played in the background from hidden speakers. The builder made a speech, applause was duly given, politicians made speeches praising him for building such a wonderous machine, the cloth was withdrawn to gasps of astonishment and then all the politicians were invited to board the aircraft, with the builder (who was also the pilot, since he knew more about the aircraft than anyone else) for the first flight. They made their way onto the invisible aircraft, strapped themselves into their invisible seats and then the propeller started to spin and they all taxied out to the runway. Soundlessly they took off and climbed to three thousand feet. Then something miraculous and quite wonderful happened. One of the news camera-men on the ground realised it was all a huge hoax. "Hey fellas, this is all bull$#it!” he yelled. The news-crews then captured the spectacle of the entire plane-load of passengers falling to their deaths from three thousand feet as the spell was broken and the invisible Green aircraft was revealed to be nothing more than hot-air, spin and a bunch of self-seeking politicians and a Greenie trying to pull the wool over the public's eyes. After this, the world was a much better and safer place.

These are incremental changes in an airframe which needs relatively little changing anyway. The new panel is a mixed blessing as the curved section makes it a little more difficult for students to ensure they are "wings level"...sitting in the right side it's much easier. Better (stronger) door-restraints and doors that seal properly in the door-frames should be the next "tweaks". These are minor annoyances which would benefit from some work at build-time on factory-built machines. Basically the J160 airfame is durable, low maintenance and tough as nails...just what a trainer should be.

80 hours or so after the rebuild (due broken through-bolts - see previous posts this thread) my 2.2l Jabiru engine has crankcase-fretting, oil seeping out from the front cylinder bases, and pretty clear evidence of impending through-bolt failure. It's heading back up the road to Bundaberg for yet another visit to the doctor. There must be a single word to describe how I am feeling at this time, but the English language appears curiously deficient in the precise term which adequately sums up my present state-of-mind.

Approx 200 hours per annum for my figures above.

Budget for an engine rebuild at 675 hours. Approx $8450 should cover it if it's just broken through-bolts. Budget for at least one new propeller every two years. $1400 should suffice. Budget for one set of maingear tyres and tubes every three months. $100 per set should suffice. Budget for one set of new brake calipers every two years. About $160 should suffice. Budget for four new oil filters every year. About $33 should suffice. Budget for about ten litres of oil a year. About $70-10o should suffice. Budget for two fuel filters and two air-filters a year. About $50 should suffice. Budget for a top-end overhaul every 500 hours. About $400 should suffice (including parts). Budget for a new oil-pressure sender every year. About $60 should suffice. Budget for fuel at 15 litres per hour as a good working average hourly burn-rate.

Some very interesting links to music popping up on this thread so I thought I'd add one of my own favourites. For an example of the "Master of Touch and Tone", the late and great Mr JohnHughey on pedal-steel, plug in your headphones and follow this link:- Some very fine picking from one of the legends, now sadly gone.

That's a 12-volt 17 Amp-hour absorbed glass mat sealed lead-acid battery and any specialty battery shop will have it or an equivalent.

What I find helpful when teaching circuits with relatively inexperienced students is to do a half-hour session, have a short break to refresh and de-stress, then do another half-hour. This avoids the fatigue that sets in at about the 48-minute mark in a solid hour of circuits and gets rid of the poor landings and sloppy circuits which result from a tired student grimly labouring away and then going home thinking "this is too hard, I'm never going to get this right". I try to get my students going home after a lesson with their confidence up and looking forward to their next flight, not dreading it. Learning is faster if learning is fun. A good pre-flight briefing about what you are specifically looking for in their circuit-flying is also very necessary, but the short break halfway through the hour can be a major help to a student who is somewhat overwhelmed with how much happens in the circuit.

Speed-picking or speed-playing (on pretty much any instrument) is very impressive and I greatly admire those who have put the time into perfecting that aspect of playing. However, on my instrument of choice (pedal-steel guitar), tone and touch are most highly prized to bring out the emotion of the music and help the listener connect with it. One of the highest tasks of the musician is to the conduit between the music and the listener. I call it being a "good and true servant of the music". I have no intention of taking anything away from the super-fast pickers, but I'll take "touch and tone" over sheer speed any day. When your playing can bring genuine tears of appreciation to your audience's eye(s), then you're starting to become one with your instrument. I still enjoy speed-picking though, especially from a "tight" Bluegrass band.

Anyone finding a mint Hamilton 21 Marine mechanical chronometer looking for a good home I have space on my mantlepiece next to my Glashutte, Wempe, Tamaya and Seiko quartz marine chronometers. Historic Timekeepers Marine Chronometer Services in the US may have restored aircraft clocks available, but I am guessing you already know that website anyway. (www.historictimekeepers.com)

Transponder and calibrated encoder - necessary. Strobes - Necessary. New nuts and longer through-bolts on engine - necessary and don't leave without them!

Another thing to keep in mind is that the higher up any organisation you go the more the office-holders become "role-players" instead of "task-achievers". So, trying to get a senior official to approve something he doesn't know anything about invariably gets a negative response because the new idea is not perceived as helping the official build his empire, increase his prestige, or gain promotion. He's a role-player. Whether the SAR effort is successful or not, he'll still look good. Often the best approach is to simply go out and do the job and achieve a successful result. Task achieved. Once presented with a fait accompli and the usual media coverage, few bureaucrats or senior officials will nay-say the use of non-standard assets, or non-approved personnel. What they will do is find a way to take all the credit. Basically the blokes on the ground are task-achievers. The higher up the food-chain you go, no matter what the organisation or how good the intentions, you just meet layer after layer of role-players and empire-builders. Having seen some classic examples of what happens when the bureacrats are left to run the show and ignore advice from the chaps at the "sharp-end" (remember the Four Corners program entitled "Search Without Rescue"?), I'd think twice, and twice again, before I ever offered my services in any capacity to anyone involved in Search and Rescue. I also visted AMSA HQ in Canberra quite a while ago and after that visit I decided to go down with the ship rather than await rescue. It's a quicker way of dying. BTW, for those who may think I have become disillusioned, you are completely wrong. I had no illusions to start with.

Ran mine on 98 Octane BP Ultimate for a while. Ran beautifully. No detonation problems at all, but very susceptible to carby-icing on humid winter mornings. This was very annoying unless you knew what was going on and took care to clear the carby before takeoff. My 912 Rotax runs on nothing but BP Ultimate. BTW, I have never found alcohol in BP Ultimate. "No-Name" or discount outlets are not selling the same 98-octane product...I found 10% alcohol in 98-octane fuel from "Enhance" in Albion Park Rail. (They clearly state they have alcohol in their fuel, so you can't say you haven't been warned.) IMO the failing through-bolt issue isn't related to fuel octane-rating (and never was), it's related to the old-style (half-height) nuts on the through-bolts. Why else would Jabiru change to a new, longer style of (12-point) nut and increase the length of the through-bolts to accommodate them? If you want to see where the problem is, look for the changes in the replacement parts after the factory has worked on the unit, and ask yourself why there is a service bulletin out about through-bolts and new nuts. Your Jab engine will fun perfectly on 98 Octane fuel as long as it comes from one of the three big brands. I only use the BP product because there are several outlets nearby and it's convenient. It loves Avgas, though.

My first blue-top 582 went 762 hours and was still running when it was sent away for a rebuild. My first Jabiru 2.2l engine made 675 hours before it failed. Just for comparison. Unlike motor vehicle engines, aircraft engines are consumable items. They run, then they break or wear out or run out of hours. You re-build or replace them and start the logbook from zero hours again. It's all part of the never-ending cycle of aircraft-engine life.

If I recall correctly, microlights with the 582 Rotax accept a 72" prop. The pitch-angle would be somwhere between 13-17 degrees, such that the static RPM at max throttle on the ground doesn't exceed about 6200RPM, which means it will not exceed 6500RPM in-flight. The pitching of a prop for a 2-stroke is critical! The propeller is the load that ultimately determines how hard the 2-stroke works. Get it wrong and you can damage the engine severely in a very short time. Major Millard would have more up-to-date info. Shoot him a PM and see if he can help.

All I have ever put in my 912 UL S is 98 Octane BP Ultimate. Runs like a top. Oil and filter-changes every 50 hours (AeroShell Sport Plus 4). I have never found alcohol in BP Ultimate. I found 10% alcohol in 98-octane unleaded from a discount supplier. Fortunately it wasn't destined for my aircraft.

A bit of trivia on Torque-Seal. The solvent in it is methanol and ethanol, just in case it goes a bit hard in the tube. Very useful stuff.

After ten years in the merchant marine as a radio officer I had little trouble transitioning to airborne radio practice (I do miss the morse though). I observed many pilots delight in speaking fluent "mumble" at 110 words-per-minute. Others like using non-standard phraseology, liberally interspersed with "um" and "ah". Others remove the first word with their PTT. Some manage to combine all these attributes. Our friends from the sub-continent add to this with thick, even impenetrable accents and an inability to formulate a reply when they are asked something non-standard. They don't speak English as their first language and they don't think it either. I regard this as "part of the rich tapestry of life". After listening to Koreans on ships trying to speak English (with a very thick Korean accent) to Greeks on ships trying to speak English (with a very thick Greek accent), there are few transmissions I cannot make some sense of. Occasionally, just occasionally, you hear someone who speaks clearly, at a modest pace, says what they have to say using standard terminology and then gets off the air. It's refreshing. So, speak clearly, slow down and when in doubt, mentally rehearse your radio call first, then make it on-air. It's not rocket science; it's much harder.

Jabiru are scrupulously honouring their rebuilt engine warranty. I'm more than satisfied with this outcome.

Relatively few factory-built STOL ultralights are available for training, especially ab initio. Usually people train first on a Gazelle, or a Jabiru, or a Lightwing, or a Tecnam, then get some time on something like a Savannah VG or a CH701 after they have got their pilot certificate. I don't know of any RA-Aus organisations that have specific STOL a/c for training. A Gazelle will give you useful experience on a high-drag airframe, then I'd suggest getting a few rides with an instructor in a factory-built Savannah - if you can find one. Once you have your pilot certificate is is simply a "conversion" to a different type of aircraft. If it is your own Savannah, that's different, you can still be trained to fly it. Conversion training in a kit-built STOL aircraft you don't actually own is outside the intent of the regulations.

My understanding is the coil-pack is from a Kubota tractor. Take it to a Kubota spares outlet and see if they can source a replacement.

My engine rebuild was my very own engine, not a factory rebuilt unit from someone else. That was part of the lengthy delay...I wanted the same engine back which I sent them. It had to wait in the queue until it could be rebuilt, then it had to wait in the queue for the engine test-stand run-in. I don't know how many other engines were in the workshop for rebuilds at the time. I also don't know what delays were caused by catastrophoic flooding around the area just after Christmas. Basically I chose a very bad time to have an engine-failure - 2 days before Christmas, and I also chose a very bad manufacturer because the factory was in an area which had a major flood. In retrospect these were both very bad decisions. Next time I have an engine failure, I'll try to choose a better time of the year and an engine from a different manufacturer. Warranty for rebuilt engines is 200 hours or 12 months.