Ocean shield

Autonomous underwater vehicle Bluefin-21, deployed in the southern Indian Ocean, has completed its first mission in the search for flight MH370 without success.

Designed with an operating depth limit of 4,500m, the launch of Bluefin-21 into the hunt comes after four acoustic signals were detected in the search area last week, which teams believed could be from the missing jet’s black box flight recorders.

An Australian ship, Ocean Shield, had picked up the four signals. A fifth signal, which was an audio signal, was picked up by an Australian aircraft in the search area.

The move comes amid fears that batteries of the aircraft recorder are two weeks past their 30-day expected life.

"To account for inconsistencies with the sea floor, the search profile is being adjusted to extend the sonar search for as long as possible."

In a statement, Australia’s Joint Agency Coordination Centre (JACC) said: "After completing around six hours of its mission, Bluefin-21 exceeded its operating depth limit of 4,500m and its built in safety feature returned it to the surface."

The data accumulated by the submarine is currently being extracted and analysed.

If weather conditions permit, the Bluefin-21 is planned to redeploy later today, JACC said.

The US Navy was quoted by BBC as saying: "To account for inconsistencies with the sea floor, the search profile is being adjusted to extend the sonar search for as long as possible."

The missing jet disappeared off radars on 8 March with 239 people onboard.


Image: Bluefin-21 robotic submarine unsuccessfully completed its first mission in search of flight MH370. Photo: courtesy of LSIS Brad Darvill/ Royal Australian Navy.

Defence Technology