geoffreywh Posted May 24, 2010 Share Posted May 24, 2010 I had just 100 hourly'd a J230, Factory built 100 hours old. I flew with the owner and commented on the amount of vibration . I came back to the airfield the next day and checked the prop. All was within specs. Strange, I thought, although torqued up the prop bolts didn't feel right. ( they (Jab) use bolts and nuts with a stack of cup washers to retain tension). You have to hold the bolt with a spanner whilst tightening with the torque wrench. Holding the spanner I could feel more torque than I should have. I know it sounds unlikely but after 50 years working on motorcycles you get a "feel" for unusual things......So rightly or wrongly I turned up the torque, still the same feel. Bad. Now what?.. Feeling that I may have stretched the bolts I went and got new ones (An4-46a...180km drive!) plus new nuts. Removing the original bolts I was HORRIFIED to see that the nuts were torqued up against the end of the threaded part of the bolts!!!! PLUS the bolts removed were 1/4 inch longer than the parts listed ones. PLUS they had washers under the bolts and nuts (not specified on the parts list). So some bright spark at the factory had used wrong bolts, used washers to take up the slack, got it COMPLETELY wrong and sent the aircraft out with a prop held on at bugger all inch pounds. I thought that there was a lot of thread showing on original bolts. They did their best to set me up for a liability suit when the prop came off! ......... Link to comment Share on other sites More sharing options...
sseeker Posted May 24, 2010 Share Posted May 24, 2010 Disappointing to see such poor effort in such an Australian icon and a beautiful aircraft, what's happening now? -Andrew Link to comment Share on other sites More sharing options...
Guest burbles1 Posted May 24, 2010 Share Posted May 24, 2010 That's the sort of thing that can lead to hundreds of deaths on RPT - when the wrong parts are used, that are made of the wrong material with inadequate strength. Pretty shameful. Check Ian's post http://www.recreationalflying.com/forum/casa/98216-casa-final-caap-51-2-1-detecting-reporting-suspected-unapproved-parts.html#post200189 Link to comment Share on other sites More sharing options...
markendee Posted May 24, 2010 Share Posted May 24, 2010 A product is only as good as it's quality control. If the person using the wrong bolts new that it would be picked up by an inspector it's my guess he or she would not have fitted them. Who test flies the finished factory built aircraft? Lots of questions here. Mark D Link to comment Share on other sites More sharing options...
monty Posted May 24, 2010 Share Posted May 24, 2010 Sorry to hear this Geoff, I suppose it was the last thing fitted on a Friday afternoon and they were thinking about the weekend or something. Have you contacted the person you bought it off? or the manufacturer where it was built? and what did they have to say.I don't think anyone will admit liability. However I am glad to see that you had the common sense to investigate the vibes and not just fly it because that is how it came from new.That's how easy someone can have an accident. Well done Geoff!! Monty Link to comment Share on other sites More sharing options...
Tomo Posted May 24, 2010 Share Posted May 24, 2010 That is sad to hear Geoff, I'm a little bit disappointed myself. However I am glad to see that you had the common sense to investigate the vibes and not just fly it because that is how it came from new. I have to congratulate you on that as well. Sadly, you'll be surprised how much work we get that has resulted in that exact thing -(not aviation btw)- bolts bottoming out, running out of thread etc etc... On reconditioned items, and new. Unfortunately it's just one of those things. Not ideally a small matter on something like a prop though... that's plain dangerous. Link to comment Share on other sites More sharing options...
GraemeK Posted May 24, 2010 Share Posted May 24, 2010 Very disappointing if that occurred in the Jab factory .... But well done Geoff in picking it up - it just shows how important depth of experience (backed up by gut feel) is in detecting problems before things go badly pear shaped. How many of us would have picked it up? Link to comment Share on other sites More sharing options...
Guest basscheffers Posted May 24, 2010 Share Posted May 24, 2010 You never did say if that was the source of the vibration, did you find it? Link to comment Share on other sites More sharing options...
riverduk Posted May 24, 2010 Share Posted May 24, 2010 bolts bottoming out, running out of thread etc etc... On reconditioned items, and new. Unfortunately it's just one of those things. Just one of those things ???? If I was spending 80 - 90K or more on a new aircraft, no matter the brand I can assure you if I found poor workmanship or quality control had been applied to it's manufacturing process, it sure as hell would not be "just one of those things" It must be assumed that the owner has on more than one occasion taken friends or family members up for a fly in his new pride & joy in the preceding 100 hours, putting not only himself but others at risk, had the bolts / prop let go. I hope that the first phone call Geoff made was to the factory to let them know that incorrect parts were fitted from new so that they can check out how a situation like this arose. I also hope that the factory has the the courage to check it out and not just sweep it under the carpet, as so many companies seem to do these days. Geoff, I also hope you did ring the factory before you posted this thread as they do deserve a right of reply. Having said all that, congrats on a job excellently done, it just goes to show that you can not buy experience, it must be earned over time, to me it sounds very likely that your 50 years on motorcycles held you in good stead in this situation and because of that the aircraft is a lot safer than it was, cheers, the Duk. Link to comment Share on other sites More sharing options...
geoffreywh Posted May 25, 2010 Author Share Posted May 25, 2010 an update...Yes it seems that the loose prop was the source of vibration. I cannot be certain until I fly in the 230 again. I have written to the factory and sent some of the bolts back to them asking for an explanation (and reimbursment for the bolts!). I will also send a letter to the RAA for their "incidents and accidents page". I have noticed while working on Jabiru's several instances of poor quality control or just poor design ......i.e. There is a flexi tube that connects the aircleaner box to the carb. The between the flexi tube and the carb. there is a short fibreglass tube.This fibreglass tube (about 3 mm wall) is held onto the carb by a hose clamp. The trouble starts when you tighten the hose clamp. You will find that the fibreglass tube may pull off the carb quite easily due to the fact that the hose clamp cannot tighten down onto the carb mouth. The f/glass tube does not allow any shrinkage. Solution? slot the tube or use "monster power" hose clamps and tighten with a socket. Otherwise your fuel mixture will go really wrong (weakened, lots) It's such a shame as they (Jabiru's) could be so good. But as often quoted "The devil lies in the details".......Geoff Link to comment Share on other sites More sharing options...
facthunter Posted May 25, 2010 Share Posted May 25, 2010 Few interesting points One lesson here. IF you have a vibration in an aircraft engine get back on the ground and investigate it. Something is always wrong. The other interesting point, is how come there are incorrect length bolts around in a factory to be ABLE to install them incorrectly? Murphy's Law. ( the gudgeon pin circlips have been changed from a square section to a round one. How long before they are installed incorrectly?). Remember that when you think you have a foolproof system, fools use such incredible ingenuity to get around it....Nev. Link to comment Share on other sites More sharing options...
Guest basscheffers Posted May 25, 2010 Share Posted May 25, 2010 Well, you get what you pay for and there is a reason most LSAs with similar performance to a J160 cost 50% extra. (or more!) You feel it in the controls, you hear about it in the cold start problems and see it in the regular 400 hour aircraft being sold with a 200 hour engine. Don't get me wrong, Jabs have an excellent safety record and get many people flying for relatively little money. I have flown them and would be more than happy to fly them again. But I wouldn't buy one. Link to comment Share on other sites More sharing options...
Bruce Tuncks Posted May 25, 2010 Share Posted May 25, 2010 Jabiru quality control Well I sure would buy a Jabiru again. Now there is no doubt that the factory stuffed up with these prop bolts, luckily this one was sold to a smart guy, one who deserves an apology. But no matter how much money you spend, there is no guarantee that you won't get something like this happen. Multi-million dollar aircraft have the odd fault like this, alas they are all built by fallible people, and when a couple of mistakes coincide ( in this case the worker and the factory inspector) then such a thing slips through. The story is a good lesson about maintenance. Bruce Link to comment Share on other sites More sharing options...
Vorticity Posted May 25, 2010 Share Posted May 25, 2010 Unacceptable from jabiru but not isolated. I've seen a tecnam where the flaps were built incorrectly. There is definatley value in doing a very thorough acceptance inspection when you buy an aircraft. Don't completely trust a busy assembly line no matter if it is in Bundaberg, Europe or the US. Link to comment Share on other sites More sharing options...
Modest Pilot Posted May 27, 2010 Share Posted May 27, 2010 The Sensenich prop (bought from Jabiru) require bolts 1/8" longer than the regular prop. Wonder if this was the mistake Link to comment Share on other sites More sharing options...
Tomo Posted May 27, 2010 Share Posted May 27, 2010 Just one of those things ???? If I was spending 80 - 90K or more on a new aircraft, no matter the brand I can assure you if I found poor workmanship or quality control had been applied to it's manufacturing process, it sure as hell would not be "just one of those things" Yes I understand you're reasoning, and I certainly wouldn't like the fact if it was mine. But things do happen, and just yesterday a brand new item was found faulty only after it was put to use - which then required a complete pull down to replace it. Down time on a machine plus labour costs the company the product was from, money. Even though it was a product that was robot made and lots of quality control, it failed under load... Not an excuse, but things do happen! :ah_oh: Link to comment Share on other sites More sharing options...
jetjr Posted May 31, 2010 Share Posted May 31, 2010 "The Sensenich prop (bought from Jabiru) require bolts 1/8" longer than the regular prop. Wonder if this was the mistake" Ill put money this was the problem Should have been picked up in test flights though Link to comment Share on other sites More sharing options...
Steve Donald Posted July 10, 2010 Share Posted July 10, 2010 Mistakes happen As careful as one can be things sometimes go wrong, parts failure or human factor combinened , Just recently a near new Cessna 206 in Darwin had a routine service and the lame noticed that in the tailplane had a whole row of rivet's which had missed the stringer rib they were into nothing but the skin. Just shows it can happen and does happen, hence keep a close eye on everything especially new Aircraft or anything for that matter, even if the percentage of build faults are very low you never no when it will occur but rest assured it will. keep a regular good look for the first 100hrs check bolt tensions engine mounts' exhaust, intakes, carb mounts, under-cart, wheel bearings brake ajustment , i recently saw a 912 hanging on loose bolts at 50hrs not good. Happy flying Link to comment Share on other sites More sharing options...
Guest hatrack Posted July 10, 2010 Share Posted July 10, 2010 I know a bloke who had one strut 40 mm longer than the other on his factory built Jab. Dont like badmouthing , but dont like to hide the truth either. Link to comment Share on other sites More sharing options...
Steve Donald Posted July 12, 2010 Share Posted July 12, 2010 Did he do a lot of flying in circles?Seriously though, did the plane get delivered like that? How could it pass a test flight? At what stage was it discovered? No offence, but I'm having a great deal of difficulty in believing this is possible. Hi hey that put's one wing about 150mm higher on 1 side at the wingtip, it would fly like a duck with a broken wing, hell it would look odd and so obvious Hmmm it would take 2 bottles of scotch and a hack saw to manage that mistake. Link to comment Share on other sites More sharing options...
Guest Maj Millard Posted July 12, 2010 Share Posted July 12, 2010 Or two bottles of Bundy ?..... Link to comment Share on other sites More sharing options...
geoffreywh Posted July 13, 2010 Author Share Posted July 13, 2010 update mk 11 I just received a package from Jabiru containing 6 prop bolts of the correct length! No reply no explanation and, more important NO MONEY, Anybody want them? 20 bucks plus postage will get them to your door! Geoff Link to comment Share on other sites More sharing options...
Steve Donald Posted July 15, 2010 Share Posted July 15, 2010 bolts hey hang onto them the rest of the Airplane might rock uo next week. lol:keen: Link to comment Share on other sites More sharing options...
Guest Kevin the Penniless Posted July 18, 2010 Share Posted July 18, 2010 I had a radio failure due to extremely poor wiring on the push to talk button. I sent photos to Jabiru and NEVER got an explanation as to why the soldering and wiring was so poorly done. Link to comment Share on other sites More sharing options...
Tomo Posted July 18, 2010 Share Posted July 18, 2010 I had a radio failure due to extremely poor wiring on the push to talk button. I sent photos to Jabiru and NEVER got an explanation as to why the soldering and wiring was so poorly done. Just today we had a microphone cable play up on us, it was pretty new, so I quickly pulled the end off, and it was easy as heck to see what the problem was! The striped wire was way longer than needed, and it was very badly done. Fixed it up. But it was from new? Not cheap either.... makes you wonder don't it. Link to comment Share on other sites More sharing options...
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