But never a reliable system that can take decision and prioritize, adapt and reevaluate in the real time.
In the event that future aviation gets back to its former glory, I have little doubt that total automation will become the norm. What we can't have is humans on a flight deck cluttered with machine-human interfaces. A bewildering number of incidents are caused by this small void.
Systems will have an encyclopaedic knowledge every air accident ever recorded and know how to calculate around a reoccurrence. It will know the world's weather with fine detail on the route. It will know the the location of hostile armies and the moment planning permission is granted for the simplest tall object. It will create pages of ACARS while acting on the information - scrolling lists of horrors will not faze it one jot. It will never lose situational awareness, knowing where it is relative to the planet and what used to be called the fixed stars. It will not suffer stress, or any other kind of work overload - in fact it will rarely use a significant proportion of its computing power.
Decades away? Probably, but the incredible thing is we are within touching distance of such technology now. The public's acceptance? Quite a different matter.