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Measurement to aircraft reliability

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Measurement to aircraft reliability

Old 25th Mar 2018, 13:52
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Measurement to aircraft reliability

Hi all

How to measure the safety and reliability of an aircraft in an engineering perspective? For instance, comparing a new A320 to a 20 years-old A320, how can I tell people that a new A320 is more reliable by not just saying because it is new?

Thanks
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Old 25th Mar 2018, 22:00
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Originally Posted by abababbbbabab27 View Post
Hi all

How to measure the safety and reliability of an aircraft in an engineering perspective? For instance, comparing a new A320 to a 20 years-old A320, how can I tell people that a new A320 is more reliable by not just saying because it is new?
Hi
Thanks
Number of takeoffs equals number of landings always a good indicator of reliability
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Old 26th Mar 2018, 13:41
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Originally Posted by abababbbbabab27 View Post
Hi all

How to measure the safety and reliability of an aircraft in an engineering perspective? For instance, comparing a new A320 to a 20 years-old A320, how can I tell people that a new A320 is more reliable by not just saying because it is new?

Thanks
Maintenance man hours per flying hour and percentage dispatch success are the two obvious statistics I think.

G
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Old 27th Mar 2018, 14:38
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For instance, comparing a new A320 to a 20 years-old A320, how can I tell people that a new A320 is more reliable by not just saying because it is new?
That is assuming a brand new one is actually the most reliable.

Not sure how well it applies in 'real life' to aircraft but there is the well known 'bathtub' reliability curve which shows higher initial failure rates due to infant mortality followed by a long period of low failures increasing at end of life/wear out.

I suspect that if noticeable at all the infant mortality period would only be a few hours/cycles.

Anybody here have any practical experience or data ?

The other point to make is that the brand new one is not exactly the same as the 20 yr old, reliability should be better due to incorporating lessons learned over the years.
MurphyWasRight is online now  
Old 27th Mar 2018, 15:03
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Originally Posted by abababbbbabab27 View Post
how can I tell people that a new A320 is more reliable
Define "reliable."
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Old 29th Mar 2018, 13:51
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Many many years ago when I was an apprentice at B-Cal, Cal Air (were using their DC10-10's for short haul trips rather than the long haul B-Cal used the 10-30's for.
It was my turn in the tech department and was given the task with a couple of others to go through all the maintenance logs etc to try to prove that this was costing us more money to maintain. We actually proved the opposite so it was swept under the proverbial carpet.
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Old 3rd Apr 2018, 19:50
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Originally Posted by MurphyWasRight View Post
That is assuming a brand new one is actually the most reliable.

Not sure how well it applies in 'real life' to aircraft but there is the well known 'bathtub' reliability curve which shows higher initial failure rates due to infant mortality followed by a long period of low failures increasing at end of life/wear out.

I suspect that if noticeable at all the infant mortality period would only be a few hours/cycles.

Anybody here have any practical experience or data ?

The other point to make is that the brand new one is not exactly the same as the 20 yr old, reliability should be better due to incorporating lessons learned over the years.
Been working with aircrafts, transport category, which came to company brand spanking new. First year wasn´t too good as we receive planes one by one and reliability wasn´t something what you expect from new machine. Then it goes ~5 years quite nicely because people and machines starts to speak same language, then "ageing" starts to show up little by little. Daily operations were not that bad but high usage was coming visible as routine maintenance wasn´t just "oil top up´s or tyre kicking anymore". So routine maintenance issues leads to delays. Those aircrafts went away after 11years use, and around 30k on hours.

Next aircrafts came used, and badly maintained. First year was horrible. Then it starts to get better, and finally when company understands how important preventive maintenance is we got quite ok reliability numbers. (we get more time for routine maintenance and some extra works ordered for c-checks just to improve reliability on areas which are hard to reach on line)
People find way to fix problems quickly w/o time consuming wondering, and some problems fixed with spot on preventive maintenance.
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Old 4th Apr 2018, 10:32
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NEW V OLD

I WORKED FOR SAUDIA AND WE GOT LOTS OF B747s in short time (early 80s) the men all said great but I said quess how many bad parts are on them.
After time they were the best we had.
Keep them up boys
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Old 4th Apr 2018, 18:48
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The AMP should have a defined reliability programme you can get all your info from that
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