Maintenance and Pilots on the ball.
Propeller Overhaul
Actually the CASA SDR data shows that there have been many propeller failures - mostly caused by maintenance faults after overhaul!
Luckily a few canny people were able to show CASA the error of thier ways and the proposed ammendment to AD/Prop/1 died where it started.
Luckily a few canny people were able to show CASA the error of thier ways and the proposed ammendment to AD/Prop/1 died where it started.
Like CVD, CASA will resurrect the prop AD at an opportune moment.
Squawk, the error comes from assuming that the propeller failure is due to time in service and not number of revolutions / hours flown / duty cycle / environment / engine management practices / number of starts / etc.
If there was a graph that demonstrated that failure rate per 100hours was directly proportional to age then you might have something, otherwise you don't have anything and may actually be increasing the failure rate by fiddling with something that is working perfectly well.
I spent hours and hours painstakingly collecting data and graphing all this stuff pre personal computer. Hard time maintenance intervals is a blunt instrument for preventing failure in service in most cases. Best thing to do is design stuff that fails gracefully, slowly and visibly, admittedly perhaps not easy to do with a propeller hub.
If there was a graph that demonstrated that failure rate per 100hours was directly proportional to age then you might have something, otherwise you don't have anything and may actually be increasing the failure rate by fiddling with something that is working perfectly well.
I spent hours and hours painstakingly collecting data and graphing all this stuff pre personal computer. Hard time maintenance intervals is a blunt instrument for preventing failure in service in most cases. Best thing to do is design stuff that fails gracefully, slowly and visibly, admittedly perhaps not easy to do with a propeller hub.
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Actually the CASA SDR data shows that there have been many propeller failures - mostly caused by maintenance faults after overhaul!
Luckily a few canny people were able to show CASA the error of thier ways and the proposed ammendment to AD/Prop/1 died where it started.
Luckily a few canny people were able to show CASA the error of thier ways and the proposed ammendment to AD/Prop/1 died where it started.
I must thank you for your help on that, it was outstanding 
Pb, if they try it again you can be sure at least three of us will kill it off just as quick....actually quicker, we have all their data to use against them at will.
Given that CASA produced the thought bubble without an objective analysis of its own data in the first place, I hope your optimism is justified. (And more power to Mr P's arm and everyone else who called BS on the first attempt. Unfortunately, no amount of data deterred CASA from reinstating the BS periodic instrument calibration check requirements.)
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For the engine nerds among you.
Pilot had the bugs fixed properly and sent in this video. If Carl Goblet was able to get youtube in the after life he would be a very happy man
35" 2450 and 60+dF LOP. And running smooth.
Enjoy
Pilot had the bugs fixed properly and sent in this video. If Carl Goblet was able to get youtube in the after life he would be a very happy man
35" 2450 and 60+dF LOP. And running smooth.
Enjoy
I can smell the cookd clys and burnt valvs from hear! (Where's yr right when we need him?)
Arguments based on an objective assessment of valid data and risk are not "puerile", except for those who can't stand their superstition-based beliefs being challenged.
"Puerile" is suggesting that those of us whose lives depend on propellors are advocating that we just fly them until they fail.
Pointing out what an objective assessment of the data shows will increase the risk of propellor problems actually contributes to safety. That assessment results in a strategy for reducing the risk of problems and failures by not having arbitrary time-based mandatory meddling.
You're not from CASA by any chance? Or make money out of propellor overhauls?
"Puerile" is suggesting that those of us whose lives depend on propellors are advocating that we just fly them until they fail.
Pointing out what an objective assessment of the data shows will increase the risk of propellor problems actually contributes to safety. That assessment results in a strategy for reducing the risk of problems and failures by not having arbitrary time-based mandatory meddling.
You're not from CASA by any chance? Or make money out of propellor overhauls?
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Lighten up leady
Drive your prop till its destroyed. Doesn't concern me.
Probably both CASA and prop overhaul shop owner for all you know.
BTW your post #27 epitomises puerile
Drive your prop till its destroyed. Doesn't concern me.
Probably both CASA and prop overhaul shop owner for all you know.
BTW your post #27 epitomises puerile
I'll take that as a 'yes'.
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Eddie and Yr right are not one and the same, trust me.
But for Eddie's benefit, the prop issue relates to an AD requiring props to be overhauled at a defined time which on a charter plane would not be a problem, because it would do the hours inside that time. But for a private plane doing 200 hours a year or less it was madness.
The data showed there were no such serious issues, and the notion of propellors typically on a dusty old C172 that had not seen a LAME in 20-30 years suddenly becoming compliant with a new AD was childishly naive at best. Those few rogues that were never in the system would not ever become part of the system anyway.
What would happen is plenty of props that were of a certain date would be removed when the manufacturer did not warrant it and the data showed the vast majority of the defects were as a result of being removed and refitted after work was done.
This had nothing to do with routine maintenance at all.
Feel free to give me a ring Eddie and there will be a class in Adelaide in November (date tbc) if you are up for it mate.
But for Eddie's benefit, the prop issue relates to an AD requiring props to be overhauled at a defined time which on a charter plane would not be a problem, because it would do the hours inside that time. But for a private plane doing 200 hours a year or less it was madness.
The data showed there were no such serious issues, and the notion of propellors typically on a dusty old C172 that had not seen a LAME in 20-30 years suddenly becoming compliant with a new AD was childishly naive at best. Those few rogues that were never in the system would not ever become part of the system anyway.
What would happen is plenty of props that were of a certain date would be removed when the manufacturer did not warrant it and the data showed the vast majority of the defects were as a result of being removed and refitted after work was done.
This had nothing to do with routine maintenance at all.
Feel free to give me a ring Eddie
and there will be a class in Adelaide in November (date tbc) if you are up for it mate.
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A mate was quoted 8k for an overhaul of 2 bladed hartzell with ~500 hours on it but just expired on calendar, second quote for the same thing different shop 4k
Another mate with similar prop new still in box but just out on calendar time 4k to overhaul.
Only time a turbine has failed me in 17 odd years of flying them was due to seized prop bearings creating a Np overspeed resulting in the overspeed governor cutting the fuel flow back so only able to get 30% Tq.
Just months out of overhaul, unfortunately not greased by overhauler or LAME when fitting, not pointing the bone, mistakes happen, just highlighting that human intervention exposes extra risk.
Another mate with similar prop new still in box but just out on calendar time 4k to overhaul.
Only time a turbine has failed me in 17 odd years of flying them was due to seized prop bearings creating a Np overspeed resulting in the overspeed governor cutting the fuel flow back so only able to get 30% Tq.
Just months out of overhaul, unfortunately not greased by overhauler or LAME when fitting, not pointing the bone, mistakes happen, just highlighting that human intervention exposes extra risk.
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Forgive my ignorance as a dumb panel beater. Aluminium CHUNKS shaped into propellers seems to be below my metalurgical training which includes simple UHS, UHSS, UHSLA, Alloy Composite, Graphite Composite and Boron. Occasionally i get to play with something as complex as mild steel or aluminium sheet.
I am seriously struggling with the concept of overhauling an aluminium fixed pitch propeller.
What is there to overhaul?
Some will say, oh its had stone chips which have been filed etc, we need to correct those. Hang a sec....that nick was filed by a LAME that knows what he is doing! I paid him to do that, and now you say i need to pay to fix his work.....................
All you will get back is a prop that has had even more filed away.
Somewhat cheeky to call it an overhaul when it should only be a NDT...which can be done without removing the prop and introducing another maintenance induced fault.....for which the owner pays..
Damm wish i had that same cash cow in my industry
I am seriously struggling with the concept of overhauling an aluminium fixed pitch propeller.
What is there to overhaul?
Some will say, oh its had stone chips which have been filed etc, we need to correct those. Hang a sec....that nick was filed by a LAME that knows what he is doing! I paid him to do that, and now you say i need to pay to fix his work.....................
All you will get back is a prop that has had even more filed away.
Somewhat cheeky to call it an overhaul when it should only be a NDT...which can be done without removing the prop and introducing another maintenance induced fault.....for which the owner pays..
Damm wish i had that same cash cow in my industry