at the end of its fuel line, it's in extremis. that's the point upon which the plane is going down. >> we've got john ostrow on the line now. can you hear me now? >> cane hear you. >> this report about the partial ping. i suppose the key interpretation of this, depending on who you talk to, is does it indicate perhaps more mechanical failure than a more nefarious reason for why the plane went down? >> that's the key to understanding this ping. really what investigators are looking at right now what is the significance? what actually causes a partial ping on the aircraft. what's really important about this particular ping is that it's different from all the other pings that came before it. the ones that allowed inmar shat to determine the path of the airplane and where they're ultimately looking today in the indian ocean. this particular ping began on flight 370 rather than began in an automated system in the ground stations that inmar shat