which is what happens most times, with aircraft and with pilots, or whether it was done while the plane was already in the air, that they just don't know and they don't know with any certainty and probably won't until they can recover the black boxes, wolf. >> all right, evan perez, thanks very much. let's bring in our chief national security correspondent, jim sciutto. you've been talking about your sources, jim. what does this suggest, this new information. how significant, potentially, is it? >> if it's true, it core ran ates the working theory. the pilot or the co pilot or the pilot and co pilot under duress, being forced to do it or someone else managed to get into the cockpit had knowledge about how to do this. but it adds to the sense whoever did it knew details about how to fly the plane. and it also undermines another theory that's been put out