scene, are also making their way there. this is the biggest day of the air search operations. ten planes going up today to search that area. andrew, before we heard the news about the debris being spotted by these chinese search crews, there was news that the u.s. is sending a super sensetive pinger locater. what can be read into that? reporter: again, it s another link to the fact that authorities are seeing this still as the most positive lead, the strongest lead they have. what a pinger is needed for is to locate any distress beacons which may be deep, deep under water. now, the range of these distress beacons, which would identify where the flight recording boxes, the all-important flight recording boxes is, the range on those is just a couple of miles. in some places in the ocean,