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Oscar

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Posts posted by Oscar

  1. One has to ask whether the appeal of buying an aircraft that relies on a 'bang off and then crash' device for spin recovery is, in fact, a reflection on the purchasers. The 'Volvo Driver' analogy seems somewhat appropriate.

     

    Perhaps it is the aeronautical equivalent of ABS brakes and stability control. As someone who grew up with and participated in a number of forms of motorsport, both of these are nice things to have for vegged-out everyday driving - but are NOT a substitute for proper training and control reactions, and I prefer to NOT have them on the vehicles I drive.

     

    As a trained and approved RFS 'bush driver' - meaning I am approved to take a fire-fighting vehicle with other personnel on board into the serious bush, on tracks you would not ordinarily consider as passable unless a hardcore 4WD driver, I can state categorically that ABS is the last damn thing you want on the vehicle. The standard action from any RFS member with 'bush driver' training if required to work on steep country is to remove the ABS fuse if ABS is fitted - ABS intervention will cause complete loss of braking control on slippery downhill slopes.

     

    A BRS-type system should be an additional level of safety available if NO OTHER means of remediation for a predictable situation is available - i.e. structural / control circuit failure. That the FAA allowed an aircraft manufacturer to sell what is, effectively, a sub-standard product with an add-on feature that ameliorates the effects of the lack of conformance to the required standard, is a serious question. That - as a result of the bi-lateral agreement with the USA, Australia has to accept this aircraft - is an issue that should also cause concern.

     

     

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  2. There are two 'Bats, both in Australia. The Mk II is currently being re-engined from the original 582, and the new owner of that plus the mouldings (which are works of art, made in the USA) is I believe actively considering the possibility of going into some sort of production, but there's quite a way to go before that might happen.

     

    However, the 'Bat is a very different beast to the Sapphire, particularly under the skin, where the production techniques required are several orders of magnitude more high-tech in order to handle the stresses of open aerobatic championship-level work and it would not be a cheap aircraft, in terms of $$ for kgs of aircraft, to produce. It's also -from pilot reports - a typically 'demanding' aircraft to fly, in that it's not something intended for relaxing cross-country work; George Markey's sole intent for the design was for something that one takes out on the weekends and does unlimited aerobatics in in 20-minute or so bursts to satisfy that urge. Pitts performance at a fraction of the cost of a Pitts was his basic premise - and the market for that turned out not to really exist.

     

     

  3.   Quote
    An awful lot of fatalities in that accident list in just one model which is relatively new.

    Which is a major reason why my apparently confusingly-worded earlier post alluded to the idea that pulling the 'chute was the best option for the pilot in the circumstances if the thing had, as reported, started to depart from what the pilot considered to be 'controlled flight' (and it doesn't really matter whether that was a spiral dive or spin entry in this context, what matters is whether the pilot felt it was going out of his control).

     

    You have the situation where an aircraft is notorious for a fatality rate of roughly twice that of comparable aircraft and the statistics are out there to support that. The company that makes that aircraft proudly boasts that with the use of the 'chute, your chances (statistically) of being killed are about halved - or, put another way, by using the chute you bring yourself back to just an average chance of being killed. To me, that would make the presence of the big red handle in that particular aircraft far more of a 'primary safety' element than it would be in something that had a better history of incident survivability.

     

    To put it another way, if you have a reasonable fear that the damn thing is more likely than most to kill you UNLESS you pull the big red handle, wouldn't you put that option on the front burner if things go pear-shaped? In a different aircraft, you might (probably would and should) look for all other options before deciding 'it's this, or nothing'. In say a Jab. 430, the nearby golf-course might have been a feasible option, knowing that the thing would almost certainly end up somewhat damaged but also knowing they offer pretty good secondary safety. In a Maule, it would possibly be no more worry than having run out of beer and stopping by the 18th hole to grab a few cans from the Clubhouse...

     

     

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  4. As idle rumination, not intended to inflame the ether (though even 'g'day can be taken the wrong way by some), I rather doubt that this pilot in this situation had much in the way of options other than the 'chute, and it's quite possibly a paradigm case of using one being the difference between a good outcome and a possibly very, very bad one.

     

    Personally, I'm not enamoured of them BUT if I routinely flew over unlandable country, I'd seriously consider installing one. Preferably, I believe, to NOT be in a position where they are the resource of last recourse, and certainly, to me it's bad airmanship to wittingly put oneself in the situation where one is relying on the red handle if there are other sensible choices.

     

    If one reads the ATSB report I referenced earlier, a pilot who: a) takes off in an aircraft that has already exhibited unusually high oil consumption the day before the flight; b) does not abide by the POH regarding the minimun recommended oil level for operation for topping-up before take-off, and c) flies for several hours with dropping oil pressure being reported without making a precautionary landing - indeed, overflying a suitable airfield when the reported oil pressure was seriously low, despite the POH instructions - and then elects to pull the handle rather than attempting a landing in a large, cleared, flat paddock - would (I suspect) have some discussion with his insurance company before they wrote out a cheque.

     

    The 'chute doesn't save the aircraft from major damage; both the photos in the ATSB report and the media reports from the Lawson crash show that the Cirrus undercart does NOT withstand landing under the chute. You get to walk away from a wrecked aircraft. That's certainly better than NOT getting to walk away. Is it always the best possible outcome of a problem? HMMMM.

     

     

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  5.   Quote
    No worries oscar, was only replying to what you said, not the eyewitnesses.You did call a spiral a spin. Surprised that a cunning linguist such as yourself would make such an error;)

    Cheers

    All good, Merv.. it's those little quotation marks that maybe confused you, they're a shorthand way of indicating that what is between them is taken from other text or conversation. I do seem to recall that recently , a low loop resulting in a serious crash in the UK was described by an eyewitness as 'a somersault'. Well, you just can't trust the Press to get it right, can you?

     

     

  6.   Quote
    Oscar, I don't want to be a nit picky bugga, but since when does 'if it started a spiral' that it means a stall and spin entry? Its either spinning or spiraling and if these things are notorious at not coming out of a spin, and it was in a spin, it would be spinning.

    David - I reckon, from some of the 'eyewitness comments', that the commentators would hardly be reliable witnesses to the difference between a spiral dive and spin entry, and (and this is more presumption on my part, obviously) if it was sufficiently low that people looked up at the cessation of engine noise, possibly the pilot was feeling insecure about the amount of height available for recovery anyway? According to more recent news, the pilot reported his altitude as approx. 4,000 feet when the noise stopped, and Lawson's elevation is nearly 2400, so by my calculation he was about 1600 AGL.

     

    However, it's a moot point, but the pilot is around to tell the story, which is good. If you look at that area on Google Earth, there are pretty much zero Cirrus-friendly emergency landing spots; the pilot may have been merely doing a turn in the general direction of the nearby golf course before pulling the handle, I guess we'll find out eventually. Just looking at the general area, I can't see anywhere that I'd be comfortable in trying to land a Cirrus, the BRS was (I think) the only realistic option, and your idea that he may have been simply slowing up to pull the chute anyway is as plausible as any theory.

     

    It does seem that at least some Cirrus pilots go for the handle even in apparently benign situations - like that bloke in late 2012 who ended up in the middle of a large flat paddock near Gilgandra that a lot of pilots would consider pretty much ideal. (https://www.atsb.gov.au/publications/investigation_reports/2012/aair/ao-2012-154.aspx) If you look at the final report, there are several photos of the landing site, and it's fine wheat stubble for bloody miles in every direction. Does that say anything about the perception - if not the fact - that anything less than a large length of black tarmac is not the place they feel comfortable about trying to land the thing on?

     

      Quote
    Ummm.. Got any BAK books in your library?

    Merv - I am signed out for spins (in gliders, at least). I may be a bit rusty but I think muscle memory would suffice over reading the BAK handbook, even these days. A minimum of three fully-developed turns, demonstrated both with an instructor and solo, was in those days required for signature.

     

     

    • Haha 1
  7. Latest ABC report says it was in Sayers Street Lawson; a check on Google Maps shows it ended up probably about 20 metres away from some serious HT lines. There is a golf course about 200 metres from where he ended up, but longest fairway appears to be about 300 metres. Those are some really, really lucky passengers. BRS was about 99% the only chance in the circumstances, which is different from saying that perhaps the circumstances should not have arisen and he shouldn't have been above serious tiger country without enough bug-out height. Katoomba Airport is about 11k away.

     

     

  8. I heard somewhere that the Cirrus has a BRS as standard because it doesn't meet FAR spin recovery requirements, so if it 'started a spiral' and that means a stall and spin-entry, then pulling the red handle is the only way out. So, the pilot probably did the right thing in the circumstances, having first done a rather silly thing by taking off in it.

     

     

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  9. Recovery and movement of aircraft other than sitting on their own wheels is something that needs to be done (where possible, obviously) with very considerable care and the input of expert knowledge.

     

    I've been repairing over several years a Jab that played 'dead ants' after an EFATO; apart from the broken fin replacement, the major repair work was a result of inexpert recovery techniques, where lifting apparatus was allowed to load the airframe in ways it was never designed to handle, cracking the 'glass on the fuselage. And Jabs are bloody tough, so someone did something in a really ham-fisted way.

     

    I've moved quite a few interesting aircraft in bits around the countryside on trucks / trailers, from a Victa from East Sale to Brisbane and back, to several Sea Furies, a Messerschmidt 262, A Kittyhawk, a Mosquito bomber, a Zero, my own Jab Sydney-Toowomba - Caloundra and return, bits of a B-25, Canberra bomber, Meteor, the Ultrabat Toowoomba - Bundaberg, some others I can't recall instantly. All without damage.

     

    The critical thing for doing such movement is to make damn sure the loads are carried on bits of the aircraft that are designed to handle those loads. Often, you need a decent spreader bar to do the lifting, you cannot just throw a sling around something. Then, the tie-down points on the transport need careful consideration, as does the location of padding etc.

     

    If all you are doing is removing a totalled aircraft from a difficult site e.g. to clear a busy airstrip, then time is of the essence and further damage is probably both unavoidable and basically collateral to the accident. However, if you have the 'luxury' of taking a bit of time, getting expert advice and if necessary fabricating stuff to do the job properly, you will save yourself later grief (aka money in repairs..).

     

     

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  10.   Quote
    All technically correct as alwaysBUT could way simpler answer

    What if there was a cause of the breakage like leaking induction tubes, serious leaning and detonation or maybe just running too lean.

     

    Bolting engine back together and running again will have the expected result.....same again.

     

    As Oscar said no one said Jabiru did repairs and even if they did do they have skills to determine failure cause.

     

    Supports the view that explanation for failures is critically important however often difficult, so data on engine operation becomes equally important......... were EGT and CHT being monitored?

     

    Other point here is that isnt the first 50 hours after major work a common point in life for engines to fail?

    Absolutely agree on all points you make - and I think two of those are extremely important that they be recognised.

     

    The first is - as many have stated on the various Jab. engine problem threads - that it is VERY important to determine what was the actual CAUSE. There has been way too much conjecture derived from the RESULT (usually that the through-bolts are simply too weak, and for the original 5/16 bolts, that's a pretty fair conclusion, but it certainly isn't the whole story).

     

    And the second point you make that should be inscribed on the wall of every repair shop (including Jabiru's own) is that bolting the engine back together and running again will - highly likely - have the same result. Unless one can accurately determine a manufacturing fault (e.g. bad batch of components) or an obvious installation fault, then failing to learn from the lessons of history - and all that..

     

     

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  11.   Quote
    InterestingMy 3300 solid was rebuilt by jab weeks before this was announced, took it back and had bolts replaced no probs. they did not do nor was it in the instructions for others (somewhere is a set of instructions) to do the studs as mentioned above, to do these means splitting case I think. New nuts are fitted

    jj - if Jabiru did not replaced the studs, then that is certainly not in accordance with either the 2011 (JSB 031-1) or the subsequent 2013 (JSB 031-2) Service Bulletins. Both of those require bolts and studs to be replaced, plus fitting oversize crankcase dowels. Further, putting the 'new' 12-point nuts on old studs would not allow the required thread engagement, which necessitates slightly longer bolts and studs. If the pre-tension on old bolts / studs has diminished enough to allow any movement of the cranckases there is the possibility of the Loctite case joining medium becoming damaged, which allows more crankcase movement which becomes cumulative damage over time, further reducing the bolt/stud pre-tension and allowing more destructive loading as described above - or in less technical terms, allowing the engine to effectively beat itself to death from the inside out, as it were.

     

    Suffice it to say that CAMit have completely re-engineered the whole bolt/stud/nuts and crankcase joining technique system; it may look similar from the outside but it most certainly isn't!

     

     

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  12.   Quote
    Well what about hearing from you in nearly every thread about CAMit? Is that not counted as ambush advertisement? I know engine reliability is an important issue and I appreciate all the serious discussion including your inputs in regards to CAMit's work but when someone makes a joke don't take it so serious.

    There are CAMit engine owners out there reporting on their experiences. There is a guy with precisely zero runs on the board throwing ordure. Who are you inclined to believe?

     

     

  13.   Quote
    Cheer up people fair dinkum he was making a joke and having a bit of a dig no need to tear him to pieces 093_celebrate.gif.b819cda4acf84f8ea794b849a8b7287c.gif

    Sorry, but that's not good enough. Engine reliability is a life-important issue; that sort of self-serving cr&p from a clown way outside where the buses run of serious development work for the benefit of every Jabiru engine owner is nothing but ambush advertisement for his own (unrealised, and as yet completely unproven to even exist) product. You are being conned.

     

     

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  14.   Quote
    006_laugh.gif.0f7b82c13a0ec29502c5fb56c616f069.gif 011_clap.gif.c796ec930025ef6b94efb6b089d30b16.gif Come in spinner ...The post wasn't aimed at the competence of Camit in anyway, I was however taking a poke at your constant flooding of the forum about them.

     

    Hope that helps.

    No, you are transparently self-interested in denigrating the work of any engine manufacturer, despite the fact that you have no product to offer. You don't even bother to correctly attribute CAMit. It's called 'trolling', and it's recognised as one of the lowest forms of contribution to on-line discussion, the modern equivalent of xeroxing your buttocks at the Office Christmas party.

     

     

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  15.   Quote
    Update for anyone interested:Went for a spin the other week and took the 120 up with a brand new motor (recon, I assume) fitted after it failed again, but on different head bolts, less than 12hrs after my incident and repair. Lucky for them they were only in circuits.

    TT=844hrs before 2nd failure.

     

    Hopefully this new reco won't suffer the same fate....

    In Post #9 you stated that the LAME had replaced the through bolts - that is NOT a factory rebuild, that is a field rebuild. Now you tell us that it failed again, but: 'on different head bolts'. WHO did the 'repair' before it failed 12 hours later? Replacing head bolts has no systemic connection with the failure of through-bolts; however, head warping through over-temp operation and through-bolt failure resulting from detonation as a result of operation in an over-temp condition has a very definite systemic connection. New head-bolts will NOT correct an over-temp damaged head.

     

    The necessity for forensic examination of damage is NOT some idle conceit of forum members, it is a necessary condition for understanding what has happened, what remedial action needs to be done and what lessons can be learned. Rather than simply throw out shallow commentary, would it not be in your OWN interests to help in the process of improving the engine you might, one day be flying behind over Corryong? The only insult here is one you give yourself by not (apparently) being bothered to find out all the relevant information before posting- and presenting that information so that others can contribute to the information-gathering process.

     

    'recon, I assume'? Since you don't know, how is it that we are supposed to accept as completely accurate the rest of the information you have supplied concerning the operational history of the engine(s) concerned? You state that it's not your aircraft, so to be fair in your commentary, surely you should add the source(s) of your information regarding the actual condition, work etc. done on the engine(s) so forum members can evaluate the reliability of that information.

     

    You are in a position to provide useful information to all Jabiru engine owners and users - including yourself. The end result of good information could be improvements in the engine that you - like many others - fly behind.

     

     

    • Agree 4
  16.   Quote
    Phhht, if the Jab had a Camit engine it would be as close to VTOL as you could get.I heard Chuck Norris designed them.

    By which comment, you demonstrate the level of your competence to appreciate proper engineering. You were doing somewhat better with your: 'and NEXT week, I'll have the answer to all the world's aero-engine problems!'

     

    Stick to your day job. CAMit engines are flying and turning in excellent results. All we have from you is some photos of crankcases..

     

     

  17.   Quote
    Do Jabiru cylinders break? Laurie

    It would be interesting to know about the statistical incidence of that. What the standard barrels certainly DO, is bend at the base flange (particularly under detonation) and thus add a major stretching moment to the through bolts that either breaks them or reduces the clamping force so the crankcases start working (or 'fretting') against each other that starts a chain of minor damage that then continues with compounding results. The thicker bases that CAMit have introduced in conjunction with the inhibition on shutdown idea seems to me to be a sensible and cost-effective way to be able to employ steel barrels.

     

     

  18. So, one presumes, it would be a very necessary piece of knowledge to know the actual wing section and the characteristics of the stall behaviour before just deciding that 'it look the same as' and bunging on some vgs and expecting the results to be similar to that experienced on something else?

     

    This is needed information; since becoming involved in RAA-class aviation I've noticed a worrying propensity on the part of some people to rely on 'what some bloke in the clubhouse told me' combined with the ever-present 'we don't need no engineers' syndrome - and way too much of that is treated as gospel because it comes from the mouths of apparent 'experts', some of whom are L2's venturing into areas in which they have no actual competence.

     

     

    • Agree 2
  19. There's always room for improvements, but don't forget that the Seeker work was accomplished over a considerable period of time and effort and flown by an experienced (and qualified) Test pilot with all the necessary safety gear attached - especially a carefully-developed spin chute that had itself been tuned to the specific aircraft. Plus, a certified TAS probe to ensure that results were real.

     

    It certainly appears that the use of vgs should be considered always as part of a 'system', where the various interactions of components that affect the aerodynamics are very carefully considered. As Dafydd has pointed out, it's not just all about the wing and separation being controlled in a more desirable way than many designs deliver. How and what the tail feathers do downstream of the airflow off the wings is important.

     

    While pretty much all of the reporting on the 'aftermarket' attachment of vgs is generally positive, I suspect that there could be a world of difference between a conservative use of them to 'smooth out' nasty sudden separation characteristics and deciding that a large bucket of them and some glue can change your lead sled into a Piper Cub. I personally wonder - as a complete non-engineer - what structural effect on the wing spar loading you might get from considerably increasing the lift available outboard while the inboard section unloads. I'd be a tad unhappy (if only very briefly) if my strut-braced thingywot with a full load of fuel in the wing tanks decided to give up the outboard section when hauling out of a tight site because I was taking full advantage of my new 'stol' capability..

     

     

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  20. ABSOLUTELY not.... I'm just an amateur etymologist. Libido is, as we know, the hopeful stories we tell ourselves that we still have it, even if we can't catch them nowadays to prove it, lubido is what we have when we dally FAR too long amongst the containers of 10W-50 at Supercheap, pretending that we're just reading the specifications. Still, what I do in my own garage is MY bloody business, thank you kindly.

     

     

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  21.   Quote
    Good point Nev. Most of us don't notice a gradual deterioration, whether it's our eyesight, hearing or lubido. The vibration level is another one; without regular reference to another aircraft, who'd notice an increasingly out of balance prop?I tend to write numbers on my flightplan as the engine warms up. Could I monitor prop balance by comparing the wobbly scrawl with previous ones?

    Lubido? Is that the measure of our sexual arousal in terms of the lubrication factor? 008_roflmao.gif.692a1fa1bc264885482c2a384583e343.gif

     

    Apologies; back to my kennel now.

     

     

  22. Er, the 6LXB in my boat had modern bearings.. and a 400K miles TBO for road use (or 40K hours for boat/auxiliary power use) - and it was legendary that trawlers would exceed that by 10 times or more, running on lard and kicks. I think the shaft alone weighed more than an installed 3300, though I could check - I still have one. When Cummins bought Gardner, they closed down the manufacturing facility, because they considered the engine too expensive to produce.

     

    And that's the point: you can't expect - as you say - a cheap aero-engine to deliver that sort of reliability.

     

     

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