The Bluefin 21 autonomous submarine was forced to halt its first mission to search for the MH370 wreckage as it dived deeper than its design limit allows.
The information comes as the investigators reveal the search using the drone would take approximately two months.
The Bluefin-21 drone was deployed after the search teams became certain the beacons of the aircraft’s black boxes had run out of battery, as no new signals had been intercepted in several days.
The US drone will now try to create a detailed sonar map of the 600 square kilometre area, which has been defined as the probable resting place of the ill-fated aircraft.
During its first mission, the drone took two hours to descend into the depths of the southern Indian Ocean but re-emerged after only six hours of scanning the seabed instead of the planned 16.
The vessel is programmed to float some 50 metres above the seabed and to return to the surface automatically in case it reaches the depth limit of 4,500 metres. Diving deeper could result in damage to the vehicle.
During the first mission, the Bluefin-21 produced six hours of data, which didn’t reveal any objects possibly resembling the aircraft.
The search area, the size of a small city, lies within the Zenith Plateau – a region never before mapped by any country, as it is of no economic significance.
According to geologist Robin Beaman, of James Cook Marine University, the seabed in the region is likely covered with the so called "foraminiferal ooze", a sludge formed by microscopic marine organisms, which would show up any large metallic object clearly.
"A side-scan is very good at detecting the difference in the acoustic return of a hard object versus a soft, muddy sea floor," Beaman said. "This is quite a good environment for looking for wreck debris, albeit deep."
The Bluefin-21 was previously successfully used to find a wreckage of a F-15 fighter jet, which had crashed off the coast of Japan last year.
In case the sonar reveals any promising sites, the drone will be sent back to take a photograph using its advanced camera capable of working in extremely dark environments.
Authorities are confident the drone is searching in the correct area and plan to scale back the air and surface search.
Malaysian authorities have still not ruled out mechanical problems as causing the plane's disappearance, but say evidence suggests it was deliberately diverted from its scheduled route from Kuala Lumpur to Beijing.
Two flight data recorders better known as black boxes located inside the aircraft, designed to record flight data and conversation between the pilots are believed to hold the only key to deciphering the so far mysterious disappearance, which has prompted the largest and most expensive aircraft search and recovery operation in the history of aviation.
More on flight MH370 here