Andrew Sarangan wrote:

The human analog of your question is a pilot becoming unconsicous
during flight. Yes, we have a backup pilot, but there is no reason why
we can't put MANY backup computers and backup power sources.

Computers will never be fool proof, but they can be more reliable than
humans, especially in repetitive tasks. Like it or not, flying is a
repetitive task.

Have you ever flown one of the new state of the art aircraft?

7 times out of 10 when you start up the aircraft you get some kind of
nuisance message or glitch, and like any computer you just go with the
old Control Alt Delete routine.
There are still too many computer glitches to even think to have
aircrafts without pilots.