Originally Posted by
OldnGrounded
It isn't, obviously, but (a) the risk event probability of all four GCUs shutting down generators simultaneously will certainly have been calculated as vanishingly low and (b) no one anticipated that any GCU would shut down because the firmware had a glitch like this baked in.
Edit: Also, if this is what occurred on the subject LATAM flight, surely it will have been the first time ever to have occurred in the wild (the sky). And it seems to me that would be vanishingly unlikely. The maintainers would have had to fail to perform the firmware/software update and the aircraft would have to have been powered up for 248 days. I don't gamble but I'd bet against that.
Exactly! It almost didn't happen at all.