for another four, five hours and that portion of the recording has been erased. as for the plight data recorder, that should hold the last 24 hours of plane performance data. so that will give as you sense of what happened with the airplane but what happened on the flight deck, we may not know. tom costello, as usual, fantastic work on this story. thank you so much for being with us. let s bring in tom powder, former director of aviation safety at the ntsb. listening to u.s. intel there seems to be two ways plight 370 kept flying for four, five hours. either another person, someone from the back of the plane, came in and hijacked the plane or maybe one of the two pilots or perhaps both of the two pilots decided that they were going to hijack their own plane and go off in another direction. do you put any credence in either of these theories? there is not enough data to put credence in any theory. you can also make the theory that something happens to the aircraft, there was some ty