From the sketchy news it sounds as if they are just searching along the flight path.

If planes go down it is usually after takeoff or before landing. They can be found even over sea. This one got lost from flight altitude in the middle of the ocean.


I do wonder, how precisely they can determine at what time the plane went down. If they cannot determine that from the radiocontacts with any precision they have to search a vast area of ocean and may never find it. How long woud any debis float on the surface?