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mertd | 3 months ago

Also not very clear how they attributed the failure to solar radiation.

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belter|3 months ago

These have specific error/data spike patterns. This document as of page 133 as good example of such investigation and conclusions: https://www.atsb.gov.au/sites/default/files/media/3532398/ao...

RealityVoid|3 months ago

It's an interesting document, but I am unconvinced that data spikes mean environmental radiation driven data corruption. The fact that they have a certain pattern suggests it's not random.

They certainly do put a chapter with potential triggers down there, and it's a good take, you can't just discard the possibility. But above, they also have SW bugs as a potential trigger, so... Essentially, they don't know for sure yet.

araes|3 months ago

CGMthrowaway has an interesting comment on the other thread about this subject, that it's likely not solar radiation. "failing solid state relay or contactor on the shared avionics power bus" [1] Related to the previous 2008 incident on Qantas 72 that had similar characteristics.

[1] https://news.ycombinator.com/item?id=46083560

  > On 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

wat10000|3 months ago

I don’t think they did. Their analysis indicates that it could, and this analysis happened as part of an investigation of an incident, but they don’t say that was definitely the cause of that incident.