The Bluefin-21 robotic submarine is about to complete the sonar scan of the area of the expected crash of flight MH370 without finding any evidence of the lost plane’s existence.
The search teams looking for the wreckage of the Malaysia Airlines-operated Boeing 777, which disappeared on 8 March, will widen the zone for the unmanned submarine to explore.
Operating at the edge of its design capabilities some 4.5km (4,500m) below the ocean surface, the Bluefin-21 has already scanned 95 per cent of the area identified as the most probable resting place of the ill-fated plane. Investigators were convinced they were looking in the correct area after several black box pings had been intercepted in this region in early April.
Based on data from Bluefin-21’s sonar instrument, a 3D map of the 120-square-mile search area has been created without providing any viable clues.
The search area is a circle with a six-mile radius off the west Australian coast.
"If no contacts of interest are made, Bluefin 21 will continue to examine the areas adjacent to the 10-kilometre radius," said the Australian agency coordinating the operations.
In the light of the unsuccessful submarine hunt, a senior US defence official said on Friday it might take years to find the aircraft.
Speaking to Reuters on the condition of anonymity, the source said: "We went all in on this small area and didn't find anything. Now you've got to go back to the big area. And now you're talking years."
Malaysia will now have to decide how to proceed with the search, including whether to bring in more underwater drones, even with the understanding that the search could continue for years as there is no further possibility to refine the search area.
Earlier this week, a piece of debris initially believed to have been from the missing aircraft, was washed ashore on a beach in western Australia. However, it was later said the object likely didn’t come from the aerospace industry.