Airbus A320 – intense solar radiation may corrupt data critical for flight

I’d really, really like to know what microcontroller family this was found on. Assuming that this is a safety processor (lockstep, ECC, etc) it suggests that ECC was insufficient for the level of bit flips they’re seeing — and if the concern is data corruption, not unintended restart, it means it’s enough flips in one word to be undetectable. The environment they’re operating in isn’t that different from everyone else, so unless they ate some margin elsewhere (bad voltage corner or something), this can definitely be relevant to others. Also would be interesting to know if it’s NVM or SRAM that’s effected.

I’d just like to point out that if you are in the computing industry long enough, you will get to see a few such incidents under different circumstances, not only in industries like aerospace. Mostly things like ECC save your a*, sometimes your software will be able to recognise a temporary spurious reading and disregard it because you had enough alternative checking logic, or in the case of realtime and safety critical maybe even your systems can take a vote between them. Got caught out by (cpu cache line) bit flips in the 90s, months of pain trying to track it down. Some of your will know :-)

The Aviation Herald has more technical details:

https://avherald.com/h?article=52f1ffc3&opt=0

Has BoFesc vibes "It's friday, so I get into work early, before lunch even. The phone rings. Shit!

I turn the page on the excuse sheet. "SOLAR FLARES" stares out at me. I'd better read up on that..."

The aerospace industry has had countermeasures in place against bit-flips for a long time, oftentimes thanks to redudancy

Airbus/Thales's fix in this case appears to add more error checking, and to restart the misbehaving component. https://bea.aero/fileadmin/user_upload/BEA2024-0404-BEA2025-...

("une supervision interne du composant à l’origine de la défaillance ; - un mécanisme de redémarrage automatique de ce composant dès lors que la défaillance est détectée)

Do they really need to ground the entire fleet for that? One incident for ten thousand planes in the air for years. I'd think that giving airlines two months to fix it would be sufficient.

We flew too close to the sun

There's a great postmortem here about what might have been a similar SEU (single event upset--bitflip) here: https://www.atsb.gov.au/sites/default/files/media/3532398/ao...

I've noticed that some carriers seem to be suggesting that there might be no impact to flights, but isn't this an immediate grounding for each aircraft until the update is made?

How is it possible that this wouldn't impact upon flight schedules?

More discussion: https://news.ycombinator.com/item?id=46082296

Apparently the fix is reverting to a previous version of the SW (see https://avherald.com/h?article=52f1ffc3&opt=0 )

Curious what a sw change might have done in terms of resiliency. Maybe an incorrect memory setting or some code path that is not calculating things redundantly maybe?

A friend works at Jetblue. They are scrambling hard to do the updates.

Solar radiation like solar wind, or sunlight? They don’t say.

This is one of the rare cases where, IMO, it makes sense to use a modified title as you've done here.

Following the Airbus A320 emergency airworthiness action, everyone will be talking about the ELAC (Elevator Aileron Computer) manufactured by Thales, which caused a sudden pitch-down without pilot input on JetBlue 1230 back in October.

So here’s everything you need to know about ELAC.

The ELAC System in the Airbus A320: The Brains Behind Pitch and Roll Control https://x.com/Turbinetraveler/status/1994498724513345637

Better not be "vibe-coded".

I was traveling during this entire ordeal. My flight got delayed by 7 hours. Insane day, just now boarding my flight. American Airlines was in shambles today.