The stupidity is coming thick and fast now.
Grounded27:
Don't get me wrong cycles and HRS are a solid rule of measure but not accurate, not absolute.
The answer to your second question is hard to answer. Did you enjoy your job, were you compensated well, were you appreciated for your skills? I am sure you count beans very well, not to belittle your task, just saying that the bottom line is you were payed to SPECULATE based on statistics.
I'm an engineer not a bean counter. The reason we use cycles and hours has nothing to do with bean counting. Those measures are surrogates for the strain history of the part in question and in metals that don't have a yield point (ie Everything except steel) the stress history determines when the component will fracture.
We make estimates based on experiment as to how long a component will last, then we apply safety factors to that estimate. When the aircraft is in service, we monitor all failures and continue testing to refine those estimates based on experience. In more than one case I dealt with, we actually reduced the number of failures by extending the time in service limits for an assembly, see if you can work out why.
In other words, try telling a turbine disk or a chunk of aluminium that its life in service is really infinite, it's just that bean counters make us change them.
Ozaub has already explained that Boeing had a problem with
quality control in relation to the adhesive system it once used. That does not mean that the process was defective, it means that Boeing discovered after the fact that it could not precisely control the manufacturing conditions tightly enough to ensure a sufficiently reliable bonding system.
Before you yappers now scream for more of Boeing s blood, by "sufficiently", I do not mean 100% guarantee, I mean to an extent to where any defects are small enough to not result in stress concentration likely to cause severe crack growth during the expected service life of the aircraft which is god knows how many thousand hours and cycles (60,000 hrs? 60,000 cycles?).
The bloody aircraft has not done badly considering, and the safety measures worked as advertised. The only issue for Boeing is that the problem surfaced considerably earlier than expected.
The question is now to work out how extensive the problem is and determine what the best inspection methods are and what the repair schemes are.
I'm also getting fed up with what I term "The pprune effect" whereby every self proclaimed expert offers a solution from within their own expertise.
By that I mean; when there is an aircraft accident, Prune attracts the computer expert who posits the cause as a software problem. The chemist suggests the fuel was faulty. The teacher wonders about the pilot training and the lawyer blames it all on criminal negligence by the designer.
If you have never worked with aircraft, I wish some of you might be a little more tentative in coming to conclusions.