A source familiar with official U.S. assessments said it was thought most likely the plane had headed south into the Indian Ocean, where it would presumably have run out of fuel and crashed. Air space to the north is much busier, and the plane would likely have been detected.
Countries contacted by Malaysia to assist in the search range from the former Soviet central Asian republics in the north to Australia in the south, along with France, which administers a scattering of islands deep in the southern Indian Ocean uninhabited except for a handful of researchers.
The Indian Ocean is one of the most remote places in the world and also one of the deepest, posing enormous challenges for efforts to find any wreckage or the flight voice and data recorders that would be key to solving the puzzle.
17 March, 2014