auto pilot and manual and both manage to crash the plane, and both had to be deliberately programmed or flown into the ground. what does that suggest to you as far as the determination? he was very determine and that is the goal, and he has had a mission or goal to kill himself and everybody on board. we deal with the terrorists and people who are not supposed to be in the cockpit, but this person is supposed to be in the cockpit, and that is scary. reporter: so we know the mechanics of it, but the question of why is what is so hard to understand. don? thank you, kyung lah. now i want to bring in alan diehl, author of air safety investigators and also matthew l. wald aviation expert and jim hall a former chairman of the ntsb and juliette kayem, and david soucie author of