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550 hour old jab going fine


Bruce Tuncks

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The current 182 I am flying with Lycoming IO-540 was at about 2380 hours (on condition) when I took it up last week. Its running great. How many jabs and rotax's do that? But how many jabs and rotax's cost upward of $40k for a replacement engine? I have seen the lycoming 360 variants up there too.

 

Horses for courses, this really is a silly debate. I love seeing personal opinion get in the way of solid facts.

 

 

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The current 182 I am flying with Lycoming IO-540 was at about 2380 hours (on condition) when I took it up last week. Its running great. How many jabs and rotax's do that? But how many jabs and rotax's cost upward of $40k for a replacement engine? I have seen the lycoming 360 variants up there too.Horses for courses, this really is a silly debate. I love seeing personal opinion get in the way of solid facts.

come to think of it, the rotax 914 and the latest 912 straddle $40k....

 

also like to add my 2c worth on those lovely Victa products. I bought one years ago when I think it had their own engine? which lasted about an hour. The replacement machine, upgraded to an alloy frame and electric start, arrived with the spark plug poking out at an odd angle. Not impressed, got refunded.

 

They now have Briggs & Stratton motors mainly, probably because they are Briggs & Strattons.

 

The Victa 150 I used was much more reliable, but they did stall a lot. But it had a lycoming motor.

 

 

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Oil changes would have to be the most necessary of the maintenance chores, but even an oil change is not without risk.

 

This guy I knew climbed out of a crashed Cessna, through where the windscreen had been, while soaked with avgas.

 

It was a rented plane from Parafield and the sump-plug had not been tightened properly after an oil change by a LAME.

 

 

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You can make any engine unreliable. Lack of use is a factor with many aircraft that just sit without any inhibiting at all. It takes over an hour to thoroughly warm up an engine in the air and that's the only way to eliminate water condensation from it .Your oil should reach about 95 degrees C or it will end up cloudy. Firing it up now and again for ten minutes is doing more damage than good. Exhaust valve stems can really deteriorate with corrosion and pitting due straight out rusting. Nev

 

 

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Not just the aircraft that are at risk from lack of exercise. It is 4 times as risky to be inactive as it is to fly.

 

There was this research guy recently called for type 2 diabetes to be re-named " lack of exercise syndrome".

 

In South Australia the need for a medical to retain a driver's license between 70 and 75 has been discontinued as it was doing more harm than good. I wrote this stuff to the CASA consultation on medicals for pilots... I wonder if they will take any notice.

 

 

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so how was it the sump plug fell out? did the LAME forget to tighten it , then forget to wire it too ? Very difficult to believe.

Stranger things have happened BUT imo lack of maintenance causes more failures than incorrect maintenance.

 

 

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In aviation "it's going OK leave it alone" is not the right thing. You don't wait for it to fail. You anticipate it and check or replace and thereby prevent it. Check intervals are from general performance criteria in a stable (predictable) operating environment. Variations of operational environment SHOULD require modified inspections, but often this degree of sophistication is never achieved because the "Strictness" of the established regime is stressed and it's what might be called "too hard" to vary and provide loopholes. Maintenance doesn't envisage leaving things loose unlockwired, untested (where specified) or missing. That's just poor unacceptable breakdown of the process . Evidence of this is the prevalence of "Incidents" after maintenance, needing follow up attention. Just shouldn't be the case, but often is. Therefore be wary of any abnormal performance of a system and have it checked if noticed, post service. Nev

 

 

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Not just the aircraft that are at risk from lack of exercise. It is 4 times as risky to be inactive as it is to fly.There was this research guy recently called for type 2 diabetes to be re-named " lack of exercise syndrome".

In South Australia the need for a medical to retain a driver's license between 70 and 75 has been discontinued as it was doing more harm than good. I wrote this stuff to the CASA consultation on medicals for pilots... I wonder if they will take any notice.

Bruce, clearly the most dangerous place is bed. Most people die in bed.

 

 

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And the most dangerous time is after maintenance

 

Back in the days when I used to hire aircraft I was much more nit pickingly thorough with a plane just out of maintenance, than one with a few hours since maintenance. I was forever finding little things wrong, such as screws missing from an inspection cover. I never found a really serious problem, but that may have been luck. I know of one aircraft, sent for maintenance due to low power. Maintainers insisted that nothing was wrong. Pilot had an engine failure on take off when returning home. Cause a burnt exhaust valve.

 

It was a C172, not a Jab

 

 

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Bruce, I have no issue with your comment (basically) that 'over-maintenance' may introduce problems that did not exist.

 

HOWEVER - lack of proper inspection and rectification of problems is more than equally dangerous.

 

As you may be aware, I have been re-furbishing / re-building a post-crash similar Jab to yours, though mine is older ( airframe #50) and with more hours ( around 2700, mostly in flying school use). It was originally VH-reg ( the first VH-reg Jab. built, in fact) so it had been either LAME or L2 inspected every 100 hours.

 

That's 27 inspections.

 

In the last couple of weeks, I have been re-installing - with re-furbishing- (amongst other things) the flap actuation mechanism. I think your aircraft will have the same set-up: a manual flap handle with three detente positions: zero flap, take-off, and landing. There is a linkage rod between the flap handle and the flap actuation cross-tube - the one behind your head - horn.

 

When we dismantled the crashed airframe (an EFATO), we noticed that the rod-end at the cross-tube horn had broken at the shank - which we put aside for later work- and assumed it was crash damage. Didn't take any attention to it.

 

When I came to re-assemble, I looked at the mechanism - and it was immediately apparent that there were serious problems. The rod-ends at BOTH ends of the linkage rod between the flap handle and the flap actuating cross-tube were being badly fouled through lack of proper installation. There are witness marks on the linkage rod and wear on the cross-tube horn, plus breakage of the 'shroud' on the inner face of the flap handle.

 

The thread on the male rod-end at the flap cross-tube horn was so badly bent that it was at best hanging on by a straw. This is not trivial: the first fatal in a Victa air-tourer was caused by exactly the same bending failure from an improperly-installed rod-end.

 

Also, the 'button' on the backside of the flap handle that engages with the flap detente holes, was badly distorted, with very little engagement with the detente holes in the back-plate. Not quite as likely to be a critical failure if it disengaged - but if you are in a tight situation, you'd like your flap setting to be held properly - yes? Especially in an EFATO situation where you grab full-flap to get the bugger on the ground where best possible..

 

This is what had failed to be noticed by proper ( and professional) inspection and rectification:

 

Flaphandlebits.jpg.3f0cf862cff870809e05f5b287621817.jpg

 

 

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Good work Oscar. You won't get any argument from me about inspections in general. When my Jab was nearing completion, anybody with technical skills who came to visit was asked to do an inspection. I got something important noticed by a ships engineer during this time.

 

I am a bit surprised that the fault you have found survived the major LAME inspection which is required before flight. In my case, I had grumbled about the cost of this guy, but the inspection was a requirement to sign off the build. In the event, I thought he was very thorough and well worth the money.

 

Not that I left any deliberate things for him to find, like I did with a building inspector at Alice Springs when I left out most of the bolts which held the roof trusses onto the walls . ( No he didn't notice and while I didn't tell him at the time, I have told the story ever since)

 

Getting back to Jabirus, I reckon its a good idea even now to have an inspection from a knowledgeable person if you can get one. When Avocet visited a few years ago he obliged and I got a couple of good tips from him.

 

The crash I am referring to was in about 1966. The Cessna had departed Parafield and was on climb out to the SE when the pilot lost oil pressure. He turned back but the engine stopped and his landing ended upside down in a vineyard near Yatala jail. The pilot later told me that it was an untightened sump-plug and obviously it was not lock-wired either.

 

Mike Busch says how workshops are a "distraction rich" environment and I imagine something happened and the plug was forgotten.

 

 

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It's about the money Turbs.

 

In some types of operation there are inspectors for every step.

 

Perhaps more resources spent on inspection and checking than on doing the job.

 

But in the sort of place we would use, there would normally be just one mechanic assigned to a job. Imagine he is interrupted to check out an unrelated parts delivery and then it is lunch time and he forgets that sump-plug. After all, it was finger tight so it looked alright.

 

 

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Distraction has been a factor in many serious accidents. Called to the phone office etc is well as the discontinuity of shift changes.. If you are working on your plane and someone comes and talks to you especially about something that really attracts your full attention, you should recheck all you were doing at the time you were interrupted /distracted. Nev

 

 

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It's about the money Turbs.In some types of operation there are inspectors for every step.

Perhaps more resources spent on inspection and checking than on doing the job.

 

But in the sort of place we would use, there would normally be just one mechanic assigned to a job. Imagine he is interrupted to check out an unrelated parts delivery and then it is lunch time and he forgets that sump-plug. After all, it was finger tight so it looked alright.

If this is the norm for your operations its time to change them.

The vast majority of mechanics are careful, and don't do their work with their mates chattering around them; that's the point I made in my last post.

 

 

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Not my operation Turbs, although I do admit to a "distraction mistake" that was noticed on the ground before flight.

 

The statistics support Facthunter's statement about maintenance mistakes being a significant source of accidents.

 

One defense is to recheck everything yourself, which might mean you have to be there before cowls and covers go back on. Another is to follow Mike Busch and treat the first flight after maintenance as a test flight with the mindset that something might go wrong.

 

In the case of the sump-plug, if that first flight had been kept near the airfield, the plane would not have been wrecked.

 

 

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It's not only maintenance. How many of us insist quiet from our passengers at critical flight times?

Let's stick with maintenance before opening a whole new subject of pilots (of which tens of thousands also do not get involved in pilot-fault forced landings and crashes, lost positions and fuel exhaustion).

The picture you're painting points to taking maintenance authority off RA pilots, primarily using the academic statements of someone who may or may not have had practical experience, whereas the true picture, when you look at RAA statistics is that the overwhelming majority of owners and pilots are doing the right thing.

 

 

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Just to clarify ...ALL my considerations are from GA and done in approved workshops. A lot of it is in the crash comic and other from personal (and almost... That is close contacts) experience. Whatever happens in the U/L movement is not as well documented and I've only seen what I have seen (naturally) and that's very varied. ALL areas have their shortfalls, but I'm convinced that owner maintenance can be as good as the alternative, If people are educated (trained) as is appropriate for what they do. An Operator has the responsibility of ensuring that what is required is carried out, regardless of who performs the task. Nev

 

 

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I don't know how Turbs connects what I am saying about distractions with taking maintenance away from owners and giving it to professional shops. The opposite conclusion could be drawn but that would be just as wrong. Personally, I reckon that owner-maintenance needs defending and expanding, and I would like to see more schools conducted. In fact I would help organize and contribute to this activity and the RAAus has been told this.

 

In my many years of experience, owner-maintainers are as good as professional shops but in a different way... the owner is not under the same pressures of time and money and so tends to be more thorough. As long as the owner-maintainer sticks to the areas where he is educated to operate, there should be good work done, as Nev points out.

 

I have noticed that the best maintainers, both amateur and professional, are humble enough to seek advice and help when they are in any doubt about what to do. This site is a wonderful place to get good stuff from experienced people.

 

An arrogant attitude is dangerous I reckon, even in an otherwise smart bloke. And a distraction-rich environment is something to watch out for too.

 

 

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All are good points however finding a non arrogant, professional LAME or L2 with in depth real current knowledge on all variants of Jabiru isnt easy.

 

That manual flap mechanisim is pretty ordinary even when new. Sure had a few frights with it releasing from St 2 to 1 on short final, not only in terms of aircraft performance but the loud bang it makes.

 

Ive seen numerous attempts to improve with limited success

 

Get rid of it and fit electric version, if you have wings off it can be mounted pretty simply. Worst failure mode you have ten is flaps that wont come down or up, in either case you can handle it.

 

 

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I don't know how Turbs connects what I am saying about distractions with taking maintenance away from owners and giving it to professional shops. The opposite conclusion could be drawn but that would be just as wrong. Personally, I reckon that owner-maintenance needs defending and expanding, and I would like to see more schools conducted. In fact I would help organize and contribute to this activity and the RAAus has been told this.In my many years of experience, owner-maintainers are as good as professional shops but in a different way... the owner is not under the same pressures of time and money and so tends to be more thorough. As long as the owner-maintainer sticks to the areas where he is educated to operate, there should be good work done, as Nev points out.

 

I have noticed that the best maintainers, both amateur and professional, are humble enough to seek advice and help when they are in any doubt about what to do. This site is a wonderful place to get good stuff from experienced people.

 

An arrogant attitude is dangerous I reckon, even in an otherwise smart bloke. And a distraction-rich environment is something to watch out for too.

Bruce, could not agree more that owner-maintenance BY KNOWLEDGEABLE OWNERS is a good thing. I don't wish to go int the details, but refurbishing our aircraft has shown up so many bits of dodgy work by an L2 ( and ex-LAME) that it would make your hair drop out. We have discussed some of this directly with RAA, and produced the log-books, which shocked Jarred. - And the entries and examples we showed, were from an L2 held in high regard by some of the RAA community (though GA owners operating at Bankstown knew his reputation as a LAME and many steered clear of him).

 

But: 'by knowledgeable owners' is a key factor. I believe (though have no first-hand knowledge of this) that the SAA provides far better training and information than is readily available to RAA owners. I used to hold an approval for both minor repairs and CoA inspections for Glass and Wood gliders from the Dept. of Transport (yes, there's a clue to how ancient I am!) - and they did not hand those out with Weeties packet coupons, I had to be trained to an acceptable standard. FWIW, none of my repaired or CoA'd aircraft had any problems.

 

RAA is slowly moving towards generating the sort of information that Owner-Maintainers need to have on hand. But, I have to say as a personal opinion, that an on-line questionnaire is simply not sufficient evidence of experience for anybody.

 

There is a phrase that we all know: 'Lover's Hands'. It is applied to those who 'F@ck everything they touch'. And we all know such people. They wouldn't recognise when they have stripped a nut on tightening it. They tend to believe in 'urban myth' more than science or physics. They are the sort of people who say: 'VNE is always conservative, I've flown my XYZ 10kts in excess and nothing happened'. They are the sort of people who will tell you that 'if the oil isn't black or creamy-coloured, the engine is just fine, sport'.

 

It would be a significant step forward for Owner-Maintenance, if regional centres could hold training courses to cover maintenance beyond just looking at things to see if they are still apparently attached..

 

 

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Good comment jetjr.Many years ago, a good glider guy died when ONE flap of the HP14 glider he had built let go on finals. If this ever happens to you then you have about half a second to raise the other flap to match, or you die. So that flap connection sure is important on the Jabiru.

 

 

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