Now a fresh search is on to locate the black boxes. The boxes send signals for at least 30 days following a crash. However, experts say they can continue making noise for another 15 days or so beyond that, depending upon the strength of the black box battery at the time of the crash, said an AP report.
Black boxes are the voice and data recorders attached to a fuselage, which help investigators know what caused the crash. To catch and locate the signal, searchers will be putting to use a high-tech listening device loaned by the U.S. Navy.
If no strong signals are located before the battery on the black boxes fades away, then searchers must move on to using devices called side-scan sonar that creates an X-ray of the ocean floor, allowing experts to look for any abnormalities in the seabed or any shape that wouldn't normally be associated with the area.
Black boxes are the voice and data recorders attached to a fuselage of a aircraf
But finding the blackbox isn't easy, say the investigators.
Although authorities confirm that the plane has crashed and a British satellite company has pinpointed its last position in the Indian Ocean, the location of the plane is still unknown.
Experts in ocean currents and weather patterns will help the searchers in estimating the plane's location.
"We've got to get lucky," said John Goglia, a former member of the U.S. National Transportation Safety Board to AP. "It's a race to get to the area in time to catch the black box pinger while it's still working."