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Jaba-who

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Jaba-who last won the day on April 9

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About Jaba-who

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    Cairns, Atherton
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  1. As I interpret this: There’s no control over the carby. Essentially the carby does its thing and the device uses the CHT and EGT etc to detect which cylinders have temp changes and from these deduces that the rich cylinders can be leaned by injecting air so that the temps can be adjusted to bring them all close together. Again some assumption on my part. To make the system work properly you would have to rejet the carby to make the hottest one ( presumably the leanest one) still not too lean because this system can’t make a lean one rich only drag rich ones down to match a lean one. Assumptions on my part.
  2. Not knocking him, I’m happy for anyone to do this sort of stuff, but yep. Ive read a few stories about this type of circumnavigation and I think all of them ended up being “multipart” trips in the end due to having to stop because of seasonal bad weather in one place or other. The first book of these types of thing I read was the guy who flew the first R22 helicopter round Oz. If I recall he did part one year and finished it the next. Stopped at some point due weather which lasted for weeks and he had to go back to work etc. so came back a year or something later and picked up where he stopped. Our flying group used to do a 10 day trip somewhere across Oz every year for a decade or so in the the early 2000s and it was always a problem of juggling opposite weather pattern at opposite ends of the country.
  3. We’ve been through these horsefeathers argument so many times I shouldn’t even respond. I promise this will be the last one many aircraft of many types change engines for reasons other than a failed engine. Jabiru in particular have brought out 4 generations with multiple changes within these generations. Each time they have offered upgrades ( at significant cost) or trade ins on old generations. It’s been cheaper ( or equal cost) to get a whole new engine. - I did this with my gen 2 at 550 hours when I wanted to upgrade to the new roller cams and the new recessed pistons. Exact same $ to get a new one in a box within a week or wait 3 months for the old one to be upgraded. No brainer. Have heard of flying school who rather than overhaul their engines at 1000 hrs just changed them for a new one. Prop strike - if you have a few year old engine. Instead of all the tests and X-rays upgrading to a new one is a sensible option considering how cheap they are. Its been long stated many many times that until you get the detail at every individual with an engine-airframe time discrepancy you can not draw any conclusions as to the reason for that discrepancy.
  4. Until you present statistical evidence of that - ie that most Jab engines will be rebuilt at well under a 1000 hours - you can’t say it. I can say that it’s not correct in our flying group. We’ve had five engines over about 10 years in 3 aircraft. One of them had a single cylinder head replaced and then two were replaced because it was cheaper to replace the whole engine then to upgrade to the new pistons and roller cams. In the whole Jabiru world - I don’t know. What has been proved is there’s a wide expanse of observer bias in the aviation world. ( not just with Jabiru) where individuals get a gut feeling about something and then selectively ignore similar issues in all other brands and fixate and amplify events (or unsupported statements) involving their target. So statements like yours really do need to be backed up by some statistics before they are made else they just feed more gut feelings and generate a life of their own.
  5. Uuhhhmmm? Che?? The figures i was quoting and which were clearly explained were reliability figures as mentioned initially. figures associated specifically with engine malfunctions as used by CASA. At no time was I, nor will I, compare the types of things you have outlined.
  6. The Gen 4 engines are in production and have been for more than a year. You can buy one now off the shelf. They aren’t in any form of development or test phase. ( beyond the continual assessment and upgrades that all engines go through where if a problem surfaces they come up with changes. Just because it’s not the same as yours or because it was an early engine doesn’t mean it’s a test engine or they are using it as an experiment on the students of the school as trial engine.
  7. Well actually he’s not quite as statistically out as you first surmise. If you recall CASA used figures ( dodgy I admit but they used these in their imposing restrictions and repeated the broad estimations to the senate estimate hearing. These were: 40 engine failures or major mechanical problems and this equated to 2.6 per 10000 hours of flight. Their total figures for rotax were 1.5 per 10000 hours and LyCon at 0.8. On these figures the imposed the restrictions as they stated that they considered anything over 1.0 unacceptable - but oddly did not impose any on Rotax. But when the figures were pulled out under FOI laws and were looked at it turned out that only about 12 (as best I recall) were real problems all the others were fuel issues, other non engine component failures and several were flights into controlled airspace without clearance! etc (as we are all pretty much aware) So the real jab numbers went down to approximately a third of the published numbers (12/40) so in fact it was a bit over a third of 2.6 - let’s say 0.8 or 0.9! On a par with LyCon (if the numbers were correct - which they undoubtedly were NOT Because CASA got them without them from the RAAAus without them being carefully acquired. But still they clearly were NO WHERE near the figures CASA used. Why were they believed by CASA - a huge observer bias where they happily ignored the events happening with other engines and noisily beat their chests about the jab ones. The LyCon figures are more likely to be correct being mostly GA where things are reported more accurately, but just like the Jab numbers being probably wrong so were the Rotax figuresbut CASA were happy to use them because they appeared to show Jabs in a bad light. So all up we have no correct numbers but clearly the jab figures are no where as bad as people claimed and on the figures available actually yep- they are broadly comparable to LyCons and Rotaxes.
  8. Not sure who or what have you the idea they are testing the engines for Jabiru. Thats just bollocks.
  9. Nah. I have to be careful and always adjectify that one. Have a number of mates ( one flying and two not) who slave at the coalface of the law so i have to be ever mindful of that. Just like I never assume all practitioners of my art are as altruistic as I am!
  10. Nothing is ever " at owners risk". There will always be a vulturous lawyer and an easily manipulated widow when these things go pear shaped. It's amazing how the law so easily removes all fault from the dead victim and transfers it the living - especially if the living have deep pockets or are perceived to have deep pockets.
  11. Bit of an odd story. I don't know how true all this is. Scuttlebutt round the local traps this morning. IFR equipped C182 and IFR capable pilot ( don't know if he was on an IFR plan or if was current) Left Charters Towers with a phone call made to a maintenance facility in Townsville about going there for an oil change ( that's the story - oil change is really not a big deal to do yourself) but also had a passenger waiting for him at Mt Garnet airstrip to be picked up and taken to Atherton. I don't know if the planned time of pickup allowed for the trip to Townsville as well or if he had double booked himself. Didn't go to Townsville but headed directly off toward Mt Garnet but at some point didn't go to Mt Garnet either and tracked further east and headed toward Atherton. Crashed about 20 km from Atherton ( way past and offtrack for Mt Garnet so must have made a plan to bypass it. ) the passenger at Mt Garnet raised the alarm when he never appeared but by then he had already bypassed it and headed for Atherton. No contact or message about changing plan. Theres radio coverage at altitude in some Of the areas areas but lower down it gets patchy. I've flown that area heaps of times and there's variable mobile phone coverage as well at altitude. I was at Atherton Airport at the time and the weather was good all afternoon mostly all blue sky though a bit windy. I didn't take much notice if there was bad weather to the south west where he crashed. Often is cloud there but as best I recall it was clear there. Starts making you wonder if he was confusional at the time. Medical issue maybe???
  12. Cost predominantly. Jabiru sold engines with fuel injection to military customers for a while so they have the technology. but it would cost more than they make to have the injection systems certified for use in manned aircraft. Theres less and less money in recreational aircraft and engines. And it’s being split up between more and more manufactures. If it’s not financially viable it won’t happen.
  13. No single carb system delivers even fuel mixture to all cylinders. Even lycos and conts have uneven distribution. It’s just that they don’t measure it on most aircraft so you don’t know it, and they are big heavy cylinders which handle heat better so the cylinders don’t fail as much ( but still plenty do. ) if they are uneven so there isn’t the effort put to sort out uneven distribution cos it’s not as important. But jabs are really light, don’t have the heat sink capability of a massive amount of metal etc. so distribution becomes more important and more of us monitor every cylinder for both CHT and EGT. Yenn - you are conflating two different issues. The carby is not unreliable and it’s reliability and function is not affected or changed by the fuel control unit they’ve come up with. The carby does its bit more or less as its supposed to ( but personally I reckon it does it as marked but it’s a crap idea and I have long wished I had a normal carby that I could control leaning etc but that’s a different story. ) But the new control unit does all its stuff downstream of the carby and basically makes up for fact the mechanical pathway ( not the carby) stuffs up the work of the carby. It would be just fine if we had it feeding just one cylinder. What concerns me with the new system is it seems - maybe I’m wrong - that it relies on some cylinders running rich and then leans them match the leaner ones. Wonder how we deal with situation where none are rich ( they’re just right say) and some are already lean. Then it leans out the just right ones too make them lean to match the lean one. So now you run them all lean. So then you have to rejet the carby. Bigger job pulling carby out put it back retest it pull it out again if needed. Big job.
  14. But non-mil spec stuff of different types can be red as well. Unless you know what it is it would be very unwise to take any notice of colour.
  15. Do a google search etc or call the company. As as far as I am aware brake fluids can be all colours. Ive used a number of brands that have been green, clear or red and they are the same stuff
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