Saraceno you are not in the company now and I see what are you looking for here with your 'explanation' about the incident in Chicago. It is a poor and bad intentionated sentence and of course you are not explaining the history how it was, just the part you are interested people now. I know this FO he is an excellent chap and better pilot but we are humans and sometimes we make mistakes it is part of our job. I completely sure that it was not a issue of básic knowledge of aviation, it was a comunication problem with controller. Anyway your answer it is a little be cruel and it is not fair.