Originally Posted by
Notanatp
As for MurphyWasRight's statement that the five-bit failure was a "rational stand in for 'something happens we have not though about'," my understanding is that the regulatory issue is that you cannot have a single failure that is catastrophic, and the FAA considered five simultaneous bit flips a single failure. If the only way to create the Seattle Times-reported scenario is to fail multiple components, then is it still a single failure?
Well, it's fairly likely that five simultaneous bit flips would have a single cause (cosmic rays/EMP), so yes, it should be considered a single failure. Pretty rare (at least), of course.