[HN Gopher] Airbus A320 Fly by wire corrupted by radiation in fl...
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Airbus A320 Fly by wire corrupted by radiation in flight
Author : JohannMac
Score : 74 points
Date : 2025-11-28 20:06 UTC (2 hours ago)
(HTM) web link (viewfromthewing.com)
(TXT) w3m dump (viewfromthewing.com)
| JohannMac wrote:
| Caused uncommanded pitch down, could exceed structural integrity
| of aircraft. There are redundant units - unknown why this can
| happen given redundancy.
| mertd wrote:
| Also not very clear how they attributed the failure to solar
| radiation.
| belter wrote:
| 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/medi
| a/3532398/ao...
| RealityVoid wrote:
| 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.
| kergonath wrote:
| > 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.
| RealityVoid wrote:
| 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_.
| netsharc wrote:
| https://www.computer-dictionary-
| online.org/definitions-c/cos...
| wat10000 wrote:
| 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.
| F7F7F7 wrote:
| Presumably the same affected units are part of the redundancy
| package. The article essentially says as much.
| belter wrote:
| 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...
| bgwalter wrote:
| 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 product
| of a culture shift.
| mosura wrote:
| From what I have heard of how much Airbus pay people . .
| "Much" is the wrong word.
| kergonath wrote:
| > 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.
| ChrisArchitect wrote:
| _Airbus issues major A320 recall after flight-control incident_
| https://www.reuters.com/business/aerospace-defense/airbus-is...
| (https://news.ycombinator.com/item?id=46081628)
| userbinator wrote:
| https://en.wikipedia.org/wiki/Single-event_upset
|
| Apparently it has happened to an Airbus once before.
| belter wrote:
| https://en.wikipedia.org/wiki/Qantas_Flight_72
|
| https://www.atsb.gov.au/sites/default/files/media/3532398/ao...
| lysace wrote:
| So the patch will be physical, I imagine.
|
| ("Apply this very expensive special tape from (e.g.) 3M here and
| here.")
| SteveNuts wrote:
| I believe most A320s can do OTA software updates (including
| dowgrades)
| t0mas88 wrote:
| I've read the EASA emergency airworthiness directive, it's only
| a software change.
| lysace wrote:
| A software change that remedies solar radiation issues? Cool.
| mirekrusin wrote:
| Instead of 3 copies make 7 for majority vote?
| butvacuum wrote:
| 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.
| sxp wrote:
| 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 exposed to "intense radiation"? Vs some other mundane
| cause such as a faulty wire or mechanical issues? And what is the
| evidence supporting the former hypothesis?
| kevin_thibedeau wrote:
| > What are the prior probabilities
|
| 100% for electronics operating at altitude. Also on the ground,
| but we mostly act like it doesn't happen and are usually
| ignorant of the root cause when it does.
| RealityVoid wrote:
| 100% of what? Those things have ECC and redundancy to the
| hilt. The data corruption odds are real and higher than one
| would expect but still not very high.
| belter wrote:
| Look at pag 138...and correlation with altitude...: https:/
| /www.atsb.gov.au/sites/default/files/media/3532398/ao...
| RealityVoid wrote:
| 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".
| CGMthrowaway wrote:
| The ATSB report shows the same 150ms power bump that
| upset the ADIRU also left tidy 1-word corruptions in the
| flight data recorder. Those align with the clock cycle,
| share the same amplitude and are 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. Because these events are periodic and
| slot into the same label ID every cycle, it does not
| appear to me to be radiation
| bgwalter wrote:
| The airworthiness directive replaces ELAC B L104 with ELAC B
| L103+, without giving a reason. Unless L103+ happens to have
| better shielding, it looks like another issue.
| NedF wrote:
| How can a ~bit flip can cause something that bad? It would mean
| everything else like you mention would also be that bad. Bad
| ram, bad hard disk, loose wire, bird hits the plane, everyone
| jumps at once, leaking military jamming.
|
| Radiation should be covered under normal safety, along with
| they already shield for it.
|
| People often wrongly blame things on radiation, bit flips etc.
| when they don't know the real cause. A well known pattern.
|
| There is a Hacker News item that was on high repeat where they
| eventually they solved the ~'cosmic radiation bug' as they
| first called it. Cannot remember the link.
|
| It will not be true no matter what the, I know 'interesting'
| facts, 'I have a wiki link', crowd tell you. Real life is
| boring (and amazing). See Heisenbug's -
| https://en.wikipedia.org/wiki/Heisenbug
| cyberax wrote:
| > 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.
| t0mas88 wrote:
| 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 the replacement or
| modification can be accomplished.
|
| That's a very limiting AD. The "before the next flight" part is
| unusual, ADs often have a limit to the next inspection or X
| flight hours or similar, not immediately.
| mosura wrote:
| Is some major new solar activity imminently expected that
| explains the urgency?
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(page generated 2025-11-28 23:01 UTC)