he refused to open the cockpit door and actually the button which stars the procedure. >> the co-pilot had no reported ties to extremism. the ceo which owns german wings defended the airline screening process. >> my firm confidence in selection of all pilots training of all pilots, in the qualification of all pilots and the work of all of pilots has not been touched by this single tragedy. >> the airlines pilots reportedly go through a wide variety of psychological and physical testing during their training. but, psychological exams end once they become certified pilots for the airline. tonight, there are still so many questions including whether this disaster was an unintended consequence of post 9/11 anti-terror precautions, apartment ka also known as the cockpit door. joining us now from denver,