Originally Posted by
infrequentflyer789
Well, yeah. It isn't quite "nothing to see here", but this is exactly the sort of failure you can sometimes get with any software system going from test or staging environments (eng sim) to production - test never quite does things exactly the same. Looks like failure happened at the right place/time (ie. on the ground) and was caught by the existing self-checks.
The surprising thing for me is that this appears to mean they have not yet flown the final fix. So are all those previous test flight useless now? Was this the reason for the test-flight hiatus - ie. not that they'd finished testing (as some said) but that the software wasn't final yet?
You can go to flight test with control software which hasn't yet been certified (the certification candidate software for example). It would have to pass a whole raft of testing and quality gates to show it is fit for flight test. Unit test, software bench test, hardware/software integration testing, black-box systems test and iron-bird test. You hope to catch any problems/bug as early in that process as you can, because its quicker, simpler and cheaper to fix it at that stage. But its the nature of engineering complex systems such as aircraft that some problems only manifest when you hook everything together.
Flight test results which allow system parameters to be optimised will still be valid even if you have to go back and fix some built-in-test code. But the unit test, software bench test, hardware/software integration testing etc would all have to be repeated for the functions affected by any software change.