MH370 search sub completes first successful scan of Indian Ocean floor

The unmanned sub's first two attempts to scan the seabed
off west Australia were cut short. Investigators are also trying to
identify the source of a nearby oil slick. Photograph: LSIS Bradley
Darvill/Australian defence department/EPA

A robotic submarine has completed its first successful scan of
the seabed in the hunt for the missing Malaysian plane, but
investigators say tests have ruled out that a nearby oil slick came from
the aircraft.

The Bluefin-21's first two missions were cut short
by technical problems and deep water, but the unmanned submarine managed
to complete a full 16-hour scan of the seabed far off Australia's
west coast overnight. Data was still being analysed but nothing of note
had yet been discovered. The sub has now scanned 90 sq km (35 sq miles)
of the Indian Ocean floor.

Separately, the joint agency search
co-ordination centre said the oil analysis done in the western city of
Perth came up empty when the samples tested negative for aircraft oil or
hydraulic fluid. The oil was collected earlier this week from a slick
about 5.5km (3.4 miles) from the area where equipment picked up
underwater sounds consistent with an aircraft black box.

It was
hoped that the oil would be evidence that officials are looking in the
right place for MH370, which vanished on 8 March while en route from
Kuala Lumpur, Malaysia,
to Beijing. Searchers have yet to find any physical proof that the
sounds that led them to the ocean floor where the Bluefin has been
deployed were from the ill-fated jet.

Twelve planes and 11 ships
were scouring a 40,300 sq km area of ocean for any debris that may be
floating on the surface, about 1,400 miles north-west of Perth.

Despite
weeks of searching, no debris related to the jet has been found and
earlier this week, Houston said the surface search would end within
days. But the centre said on Thursday that crews would continue
searching the ocean surface into next week.

Malaysia's defence
minister, Hishammuddin Hussein, confirmed that the search would continue
over the weekend, though he acknowledged that officials would have to
rethink their strategy at some point if nothing was found.

"There
will come a time when we need to regroup and reconsider, but in any
event, the search will always continue. It's just a matter of approach,"
he said at a news conference on Thursday.

Radar and satellite
data show the Boeing 777 flew far off-course for an unknown reason and
would have run out of fuel above the Indian Ocean west of Australia.

A
ship-towed device detected four underwater signals that are believed to
have come from the plane's black boxes shortly before the batteries
powering the recorders' beacons likely ran out. The sounds have helped
narrow the search area to the waters where the Bluefin is now operating.

The
US navy's unmanned sub cut short its first mission on Monday because it
exceeded its maximum operating depth of 4,500m (15,000ft). Searchers
moved it away from the deepest waters before redeploying the vessel to
scan the seabed with sonar to map a potential debris field.

In
addition to finding the plane, investigators want to recover the black
boxes in hopes the cockpit voice and flight data recorders can explain
why the passenger jet lost communications and flew so far off-course
before disappearing.

| theguardian.com