The underwater drone Bluefin-21 has a maximum operational
depth of 4.5km. REUTERS/US Navy photo.
A US Navy underwater drone sent to search for a missing
Malaysian jetliner on the floor of the Indian Ocean had its
first mission cut short after exceeding its 4.5 km (2.8 mile)
depth limit, Australian search authorities say.
The launch of the Blue-fin 21 autonomous underwater vehicle
marked a new phase in the six week search for Malaysia
Airlines MH370 which disappeared on March 8 and is presumed
to have crashed thousands of kilometres (miles) off course
with the loss of all 239 people on board.
Searchers are confident they know the approximate position of
wreckage of the Boeing 777, some 1,550 km (963 miles)
northwest of Perth, and are moving ahead on the basis of four
acoustic signals they believe are from its black box
But having not heard a "ping" for almost a week and with the
batteries on the locator beacons two weeks past their 30-day
expected life, a decision was made on Monday to launch the
slow-moving undersea drone to try and locate wreckage.
"After completing around six hours of its mission, Bluefin-21
exceeded its operating depth limit of 4,500 metres and its
built in safety feature returned it to the surface," the
Australian agency coordinating the search and recovery
"The six hours of data gathered by the Autonomous Underwater
Vehicle is currently being extracted and analysed."
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.
An aircraft's black box records data from the cockpit and
conversations among flight crew and may provide answers about
what happened to the missing plane.
The Blue-fin robot will build up a detailed acoustic image of
the area using sophisticated 'sidescan' sonar, hoping to
repeat its success in finding a F-15 fighter jet which
crashed off Japan last year.
It had been expected to spend up to 16 hours scouring the
silty sea floor, after a two hour descent.
If it detects possible wreckage, it will be sent back to
photograph it in underwater conditions with extremely low
Officials are currently focusing their acoustic search on an
area about the size of a medium city - 600 sq km (230 sq
miles) - and say it could take the underwater robot months to
scan and map the whole search zone.
The search for the missing plane is on track to be the most
difficult and expensive search and recovery operation in