In my previous work we had a bunch of devices that failed at the final installation. All of them passed that test at the end of line at the plant without any issues but they simply refused to boot at the customer site. When we read the ROM contents some data was corrupted We had a very extensive investigation and finally they realized that all the ones that failed had been flown instead of using ground shipping and there had been some solar activity so the final conclusion was bit shift due to solar storm and since fixing was to difficult and expensive it was just decided to stop shipping this particular device by air (it used a very cheap flash memory)

Nice thank you, this one has the details I was curious about

In a service difficulty report submitted to the FAA the operator stated, that the Elevator Aileron Computer #2 (ELAC2) was identified faulty causing an uncommanded pitch down in cruise flight, the autopilot remained engaged

On Nov 7th 2025 the NTSB reported: "During cruise, the aircraft experienced an uncontrolled descent for approximately 4-5 seconds before the autopilot corrected the trajectory. This likely occurred during an ELAC switch change." The occurrence caused 10 injuries on board, the NTSB opened an investigation.

The subsequent investigation identified a vulnerability with the ELAC B hardware fitted with software L104 in case of exposure to solar flares.

This identified vulnerability could lead in the worst case scenario to an uncommanded elevator movement that may result in exceeding the aircraft structural capability.

I think I read that the issue is relatively new thanks to a software update (speculation in another thread, so questionable veracity). So perhaps a change that wasn’t flawed by itself but by bad luck combined with this radiation sensitivity to make the issue significant.

But also solar flares are kind of rare, especially on the stronger end, so easy to imagine bug reliant on them sitting idle for years.

As the sun rotates, the area that throws out these solar flares slowly faces toward the earth (solar maximum) then slowly rotates to face away from the earth (solar minimum). The solar cycle is roughly eleven years long.

This doesn't have anything to do with the sun's rotation. It actually rotates once every 28 days. The solar maximum and solar minimum are just phases in activity caused by internal activity.

As a ham radio operator, I can tell you solar flares can create incredible and somewhat unpredictable changes in radio transmissions. Hams love it because we get to push boundaries from a safe shack, but if I was on a plane that uses radio signals to navigate I would be less happy about solar flares effecting transmissions.

Appreciate the write-up, thanks!

I found this diagram, and this should mean that the levels will drop by around 2030?

Source: https://www.stce.be/news/453/welcome.html

I work in the software industry and I have a guess regarding what the might do to "fix" the problem.

First, we look for the cause, but in this case it is external: we can't prevent solar flares. So we will turn to mitigation instead:

Data gets flaky and erratic unter radiation, so what we would do is to double- and triple-check the data bits. By adding more levels of data correction, more bits can be wrong and we can still figure what it was supposed to be.

Adding more corrections means more overhead and slower performance, but it can still be made to work within the given constraints of real-time processing. They will need to find a balance between hardening and usefulness.