The Guardian/Reuters
19 April 2014

Indian Ocean hunt by US navy deep-sea vehicle narrows to an area with a radius of just 10km

The underwater search for the flight recorders from the missing Malaysia Airlines flight MH370 could be completed in five to seven days, Australian officials said on Saturday.

A US navy deep-sea autonomous underwater vehicle (AUV), Bluefin-21, is scouring a remote stretch of the Indian Ocean floor for signs of the plane, which disappeared from radars on 8 March with 239 people on board and is believed to have crashed in the area.

The underwater search has been narrowed to a circular area with a radius of 10km (6.2 miles) around the location from which one of four pings believed to have come from the recorders was detected on 8 April, officials said.

The huge international search-and-rescue effort for any physical evidence of the plane’s wreckage, now in its seventh week, had so far proved fruitless.

“Provided the weather is favourable for launch and recovery of the AUV and we have a good run with the serviceability of the AUV, we should complete the search of the focused underwater area in five to seven days,” the Joint Agency Co-ordination Centre said.

Officials did not indicate whether they were confident this search area would yield new information about the flight, nor did they say what steps they would take if nothing was found.

The comment came after the agency said on Thursday previous media reports suggesting the underwater search could take as long as several months were inaccurate.

Search planes and ships from a half dozen countries had tried to catch any glimpse of the wreckage after nearly two months of daily sorties, making this the most expensive such operation in aviation history.

After almost two weeks without a signal, and long past the flight recorder battery’s 30-day life expectancy, authorities were increasingly reliant on the $4 million Bluefin-21 drone, which on Saturday was expected to dive to unprecedented depths.

Because visual searches of the ocean surface had yielded no concrete evidence, the drone and its ability to search deep beneath the ocean surface with “side scan” sonar had become the focus of the search 2,000km (1,200 miles) west of the Australian city of Perth.

The search so far had centred on a city-sized area where a series of “pings” led authorities to believe the plane’s flight recorders might be located.

The current refined search area was based on one such transmission.

After the drone’s searches were frustrated by an automatic safety mechanism that returned it to the surface when it exceeded a depth of 4.5km (14,763 feet), technicians adjusted the mechanism and sent it as deep as a record 4.695km (15,403 feet).

But hopes that it might soon guide searchers to some wreckage were dwindling with no sign of any debris after six deployments spanning 133 square kilometres (83 square miles).

Footage from the drone’s sixth mission was still being analysed, the agency said on Saturday.

Malaysian acting transport minister Datuk Seri Hishammuddin Hussein said in a Twitter post the government’s deployment of assets committee was considering using more AUVs, a possible sign of growing confidence in the vessels. He did not elaborate.

On Monday, the search co-ordinator, retired Air Chief Marshal Angus Houston, said the air and surface search for debris would likely end by the middle of the week as the operation shifted its focus to the ocean floor.

But the air and surface searches have continued daily, and on Saturday the agency said up to 11 military aircraft and 12 ships would help with the day’s search covering about 50,200 square kilometres (31,000 square miles) across three areas.