cnn analyst david and thanks to you both for joining us. david number one i want to start with you. you have written a book on the disother appearan disapeerngs disappearance of the flight. what do you think happened? well, we have narrowed it down and that means is that they re practical and reported and that they re literally facts about the investigation, so comparing those that compares those all to each other has come up with the fact that there s the most probably that there was a fire on board or mechanical. now the first term was commanded to human hand. there s no doubt about that. the fact that the captain or co-pilot made a decision or