> First most obvious, how come do pilots trust a system that has these layers of manual security checks with their lives. And second, can't it all be automated?

> First most obvious, how come do pilots trust a system that has these layers of manual security checks with their lives. And second, can't it all be automated? It's one thing to have a script check the return code of a test suite. Often times aircraft checklists include things like physically verifying that something is present and moving in the correct manner when commanded to do so. Obviously you can add sensors, but then how do you check that the sensor is working? At the end of the day, most of the manual checklist items are still for a human to look at or listen to a thing and make a judgement call.