As we seem to have drifted back to FADEC software and its construction may I add something which will probably scare those of you who are already concerned:
The Trent FADECs run the same software, developed by the same team in both lanes of the FADEC, these are also hardware identical.
However, the design and construction, code, test* etc. are so different from the commercial world that I do have confidence in the correctness of function. There are so many cross-checks - sanity checking is a good term - that I doubt that any of the scenarios painted so far could happen.
But, as I was on that team, I would say that wouldn't I???
Last time I posted on this thead I got a dire warning, so unfortunately I can't add much more.
Safe flying
VnV...
*check my moniker.