Hi Denise Moore,
There has been an interesting and continuing discussion regarding the software/human interface in Tech Log, AF447 Thread #4 which is the current one. If you have not done so, you may want to read several posts:
#273, Pg.14
#280, Pg.14
#309, Pg.16
and,
#319, Pg.16
They are all posts by Gums. He flew some of the very first FBW F-16 Falcon fighters that were originally known as Vipers. I think he has some of the concerns you have.
As an engineer, we tend to think in terms of probabilities of failure, e.g., 10⁻⁹ or thereabouts, and designs are formulated and tested on a probability basis. What often is not thought of is "possibility" of failure. Possibilities are real. This was pointed out by PJ2 in a post and he gave a link to an interesting article:
http://leeclarke.com/docs/clarke%20t...gnificance.pdf