The hunt for Malaysia Airlines flight MH370 will head deep underwater

The hunt for Malaysia Airlines flight MH370 will head deep underwater as the batteries in the flight’s black box recorders have probably died and there is little chance of finding floating debris, according to Australian search chief Angus Houston.

The search is now relying on the US Navy’s Bluefin 21 autonomous underwater vehicle, which is set to search the ocean floor for wreckage some 4.5 km (2.8 miles) beneath the surface.

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 came from from its black box recorders.

“Despite the lack of further detections, the four signals previously acquired taken together constitute the most promising lead we have in the search for MH370,” Houston told reporters in Perth.

“The experts have therefore determined that the Australian Ocean Shield will cease searching with a towed pinger locator later today and deploy the autonomous underwater vehicle, Bluefin-21, as soon as possible.

The batteries in the black boxes are now two weeks past their 30-day expected life and searchers will be relying on sonar and cameras on the Bluefin-21 drone.

The Bluefin robot will build up a detailed acoustic image of the area using ‘sidescan’ sonar, hoping to repeat its success in finding an F-15 fighter jet which crashed off Japan last year.

If it detects possible wreckage, it will be sent back to photograph it in underwater conditions with extremely low light.

Building up the necessary mosaic of thousands of images can be a long and frustrating task, a point Houston reiterated on Monday, citing the extremely large, remote and deep search area.

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.

“I would just say to everybody, don’t be over optimistic, be realistic and let’s hope, let’s hope that that very strong signal that we were receiving is actually coming from the black box,” Houston said.

Houston added that although an oil slick was located in the search area on Sunday evening, he was pessimistic about the likelihood of finding anything floating on the ocean surface after this amount of time.

“The chances of any floating material being recovered have greatly diminished and it will be appropriate to confer with Australia’s partners to decide the way ahead later this week,” he said. Reported Reuters