Search around a bit. Look for the terms “Airbus 320” and “radiation” and “grounding”.
What you’ll find in most cases is a pseudo-technical summary of the so called “root cause” of the problem that led to the recent emergency Airbus 320 recall. It’s the sun, you see — solar radiation corrupted the flight computers. But search a bit more. What’s the prescribed fix? It’s to revert to the previous version of the flight software.
Wait. What?
Reverting the software eliminates solar radiation corrupting the avionics!? Of course not. Reverting the software restores a capability that the avionics previously had: to be resilient to bad data.
And so, it seems, it was not the sun. Not the radiation. Not corrupted data. These are proximate causes. The problem stemmed from a software update. Yet even that is a proximate cause. Don’t blame the update. Software mistakes happen.
No, this was a faulty update to critical flight software that didn’t get caught during testing. And so the root cause was a breakdown in the testing process.
The sun is off the hook.