alt Hacker NewsOn the Qantas 72 flight (2008), the ATSB report showed the same power spike that upset the ADIRU also left tidy 1-word corruptions in the flight data recorder. Those aligned with the clock cycle, shared the same amplitude and were confined to single ARINC words. That is pretty much exactly the signature of a failing solid state relay or contactor on the shared avionics power bus (upstream of both FDR and fly by wire).
Radation-driven bit flips would be Poisson distributed in time and energy. So that is one way to find out
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Do you think they're using the guise of "its solar radiation" as cover to do a software update to fix a more problematic "bug", and perhaps tangentially there are some changes in said-update to improve some error correcting type code (eg: related to detecting spurious bit flips).
I'm very surprised that a plane doesn't have voltage, current and glitch monitoring on every power rail, logged to the data recorder.
You would pretty much be logging, every millisecond, the minimum, maximum and mean voltage for every 1ms period (and the same for current).
Then any failing solid state relay would be obvious in the collected data, far before you start to get word corruption!
After reset, it went away. If it was this kind of hw issue, it should still be present.
Considering those units were designed back when they did not have EDAC mandated, I can believe it could have been a bit flip (along with some other stuff they will probably address to take into consideration this failure mode). Nowadays, most MCU's have ECC on them so the time of this excuse is mostly gone now. :)