I think we are already there given that flying is a much easier task than driving. See http://www.theatlantic.com/technology/archive/2016/03/has-th...

As one conspiracy theory, low pilot pay could be the industry's way of forcing the issue, given the psychological barriers to completely automated flights. Additionally, partial automation leads to lots of boredom for pilots, which could detract from rather than improve safety (full automation avoids that problem).

We should see it happen in our lifetimes, anyways.