Originally Posted by
MurphyWasRight
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 wasnīt too good as we receive planes one by one and reliability wasnīt 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 wasnīt just "oil top upīs 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.