For reasons still unknown it crashed into the Indian Ocean on March 8, 2014, taking 239 souls with it. I think a catastrophic electrical fire is on the short list of possible causes, but that's only speculation.
The new search builds on four separate sets of information, which have now lined up: flight simulations by Boeing, signal analysis, back-tracking of debris from the plane (aka drift studies), and photos from a French reconnaissance satellite that were taken soon after the crash. The sat-photos show a cluster of floating objects that were likely artificial.
Taken together, these point to one fairly small area north of the main track:
The area of interest, 35.6 South Latitude, 92.8 East Longitude, is on the left side, where the black dots pile up. The latest studies identify a few additional places to look, but this one takes first priority.
Over the final year of the 120,000-km search, evidence started accumulating that the searchers had been looking in the wrong place. Still, Australia refused to confirm that sufficient "new data" existed to justify a changed or expanded search.
Fortunately, the company Ocean Infinity has offered to take one more look:
It's doing this as a classic salvage venture, called "no cure, no pay," so Ocean Infinity will be out a lot of money if the search fails. If it succeeds, Malaysia will pay the firm up to $70 million, with the exact amount determined by the effort.
And if successful, it will be more proof, as with commercial spaceflight pioneers Blue Origin and SpaceX, that the age of tycoons taking command is truly upon us.