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Airbus A320 Fly by wire corrupted by radiation in flight

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Re: Airbus A320 Fly by wire corrupted by radiation in flight

#31

Post by kergonath »

RealityVoid wrote: post #19
belter wrote: post #14

Earlier quoted context omitted.

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...

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…

> But above, they also have SW bugs as a potential trigger, so

They also did extensive tests and analyses and came to the conclusion that a bug was highly unlikely (they would never say that something is impossible, but it still is exceedingly improbable).

> Essentially, they don't know for sure yet.

That’s not a really fair assessment. Their conclusion is that they could not estimate the likelihood of a radiation effect, so in that sense they don’t know for sure. But they still eliminated a lot of options. Almost all of them, actually.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#32

Post by kergonath »

bgwalter wrote: post #11
belter wrote: post #3

Emergency Airworthiness Directive 2025-0268-E: https://ad.easa.europa.eu/ad/2025-0268-E https://ad.easa.europa.eu/blob/EASA_AD_2025_0268_E.pdf/EAD_2... This was the incident that triggered the investigation: https://avherald.com/h?article=52f1ffc3&opt=0 https://edition.cnn.com/2025/10/30/us/jetblue-flight-emergen... List of Airbus A320 family operators: https://en.wikipedia.org/wiki/List_of_Airbus_A320_family_ope...

According to the airworthiness directive: Affected ELAC: Elevator aileron computer (ELAC) ELAC B L104 Serviceable ELAC: ELAC B L103+ So it's a regression that affects decades old aircraft. Of course Airbus is now also meddling with "AI": https://www.airbus.com/en/innovation/digital-transformation/... Obviously there no direct connection here, but it seems that destabilizing perfectly working aircraft could be the pro…

> Obviously there no direct connection here, but it seems that destabilizing perfectly working aircraft could be the product of a culture shift.

A culture shift following a fad in the last couple of years that caused "a regression" (whatever you mean by that) in an aircraft that was made years before, and that was designed years before again? How would that work? They can stop selling aircrafts if they have a time machine.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#33

Post by [deleted] »

RealityVoid wrote: post #21
belter wrote: post #18

Earlier quoted context omitted.

Look at pag 138...and correlation with altitude...: https://www.atsb.gov.au/sites/default/files/media/3532398/ao...

Yes, look at page 135 as well. They don't know, they have educated guesses. It could be SW, it could be hw. EMI causing bugs is the equivalent of "bad juju".

[deleted]

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#34

Post by [deleted] »

kergonath wrote: post #31
RealityVoid wrote: post #19

Earlier quoted context omitted.

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…

> But above, they also have SW bugs as a potential trigger, so They also did extensive tests and analyses and came to the conclusion that a bug was highly unlikely (they would never say that something is impossible, but it still is exceedingly improbable). > Essentially, they don't know for sure yet. That’s not a really fair assessment. Their conclusion is that they could not estimate the likelihood of a radiation ef…

[deleted]

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#35

Post by cyberax »

sxp wrote: post #9

The title sounds like speculative clickbait. From https://www.airbus.com/en/newsroom/press-releases/2025-11-ai... : Analysis of a recent event involving an A320 Family aircraft has revealed that intense solar radiation may corrupt data critical to the functioning of flight controls. This is different from the core claim that the incident was caused by radiation. What are the prior probabilities that the system was ex…

> What are the prior probabilities that the system was exposed to "intense radiation"?

I suggest trying to fly with a Geiger counter. At the cruise altitude you have something like 15-20x the normal background level, when flying over the pole it can rise to 30x.

It's actually not caused by the solar radiation, it's too weak to reach the flight level. It is caused by cosmic rays, and the solar activity modulates how much of the cosmic radiation reaches the lower levels of the atmosphere.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#36

Post by netsharc »

RealityVoid wrote: post #15
mertd wrote: post #7

Earlier quoted context omitted.

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

In my humble opinion, whenever someone dropped the idea... "Maybe it's solar radiation" it never was solar radiation. There was a subtle bug in the system or something. It's just such a cop-out to attribute it to, solar radiation, it's our profession's variant of magic .

https://www.computer-dictionary-online.org/definitions-c/cos...

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#37

Post by lysace »

butvacuum wrote: post #29
lysace wrote: post #23

Earlier quoted context omitted.

A software change that remedies solar radiation issues? Cool.

Easy enough to imagine. Something improperly was judged to not need concencus, running the calculation twice, or some other software mitigation. Revise process to include mitigation.

"just run the calculation twice. surely the darned solar radiation will take care not to hit random parts of the memory or any critical registers in the cpu"

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#38

Post by [deleted] »

t0mas88 wrote: post #24

This is highly unusual, so there may be something more to it than only speculation about radiation. The emergency AD says: > Before next flight after the effective date of this AD, replace or modify each affected ELAC with a serviceable ELAC in accordance with the instructions of the AOT. > > A ferry flight (up to 3 Flight Cycles, non-ETOPS, no passengers) is permitted to position the aeroplane to a location where th…

[deleted]

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#39

Post by RealityVoid »

kergonath wrote: post #31
RealityVoid wrote: post #19

Earlier quoted context omitted.

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…

> But above, they also have SW bugs as a potential trigger, so They also did extensive tests and analyses and came to the conclusion that a bug was highly unlikely (they would never say that something is impossible, but it still is exceedingly improbable). > Essentially, they don't know for sure yet. That’s not a really fair assessment. Their conclusion is that they could not estimate the likelihood of a radiation ef…

I think it's a quite fair assessment. It's not an indictment of their engineering or anything, but they can't say for sure what caused the issue and the analyzed all they could. The conclusion is "we don't know, we have some guesses". Probably it irks me the most because "cosmic rays" are impossible to prove. It's the perfect scapegoat. If I had a penny every time that someone put it out as the possible cause of a bug... I'd still be poor, but... well, I'd have a couple of pennies.

EDIT: On a deeper read, I am inclined to be a bit more charitable to this theory because, to my surprise: "As noted in section 3.5.2, the CPU module on units 4167 and 4122 did not incorporate EDAC"

I did not consider these units were _this_ old, so they did not have error correction on them. Nowadays, most every MCU has ECC on them. So, yes, without ECC the odds are quite larger that they DID get a "bit flip"

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#40

Post by [deleted] »

lysace wrote: post #37
butvacuum wrote: post #29

Earlier quoted context omitted.

Easy enough to imagine. Something improperly was judged to not need concencus, running the calculation twice, or some other software mitigation. Revise process to include mitigation.

"just run the calculation twice. surely the darned solar radiation will take care not to hit random parts of the memory or any critical registers in the cpu"

[deleted]
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