unprecedented situation all the way around, piers. >> barbara, stay with us. want to bring in david suse author of why planes crash. aviation expert jim tillman and matthew robinson, air safety investigator. welcome to all of you. let me start with you, jim tillman. we've talked before this week about the various twists and turns quite literally of the fate of this plane. what do you make of these extraordinary new revelations? >> well, they're just about as confusing as everything else i've heard about this event from the very beginning. for example, let's talk about pings. it's my understanding that the devices don't ping until they are hitting water, until they get into water. and the pings went on and all of a sudden stopped over the indian ocean. that's just the opposite of the way that i have always understood them to work. that that should be when they really start going. the other thing is, i got to