Plan For Search To Restart On Sunday After Four Months On Hold

Plan For Search To Restart On Sunday After Four Months On Hold

Posted by Sylvester on Saturday, October 4, 2014 0

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After a four-month hiatus, the hunt for Malaysia Airlines flight 370 is about to resume in a desolate stretch of the southern Indian Ocean, with searchers lowering new equipment deep hoping to finally solve one of the world’s most perplexing aviation mysteries.

BH370

The GO Phoenix, the first of three ships that will spend up to a year hunting for the wreckage far off Australia’s west coast, is expected to arrive in the search zone on Sunday, although weather could delay its progress. Crews will use sonar, video cameras and jet fuel sensors to scour the water for any trace of the Boeing 777, which disappeared on 8 March during a flight from Kuala Lumpur to Beijing with 239 people on board.

The search has been on hold for months so crews could map the seabed in the search zone, about 1,800km off Western Australia. The 60,000 sq km search area lies along what is known as the “seventh arc”, a stretch of ocean where investigators believe the plane ran out of fuel and crashed. The belief is based largely on an analysis of transmissions between the plane and a satellite.

Given that there have been false alarms, from underwater signals wrongly thought to be from the plane’s black boxes to possible debris fields that turned out to be rubbish, officials say their are “cautiously optimistic” rather than confident.

“We’re cautiously optimistic; cautious because of all the technical and other challenges we’ve got, but optimistic because we’re confident in the analysis,” said Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, the agency leading the search. “But it’s just a very big area that we’re looking at.”

That area was largely unknown to scientists before the mapping process began in May. Two ships have surveyed the seabed using multibeam sonar devices, similar to a fish-finder. The equipment sends out a series of signals that determine the shape and hardness of the terrain below, allowing officials to create three-dimensional maps of the seabed.

Those maps are considered crucial because the seafloor is riddled with deep crevasses, mountains and volcanoes, which could prove disastrous to the pricey, delicate search equipment that will be towed just 100m above the seabed. Two of the search ships will use underwater search vessels worth about $1.5m each.

“You can imagine if you’re towing a device close to the seafloor, you want to know if you’re about to run into a mountain,” said Stuart Minchin, chief of the environmental geoscience division at Geoscience Australia, which has been analysing the mapping data.

The terrain is not the only challenge. The area is prone to brutal weather, and is so remote that it takes vessels up to six days to get there from Australia. Water depths are also tricky: they range from 600m to 6.5km.

That is about the deepest the sonar equipment can go, Dolan said.

“In all sorts of ways we’re operating towards the limits of the technology that is available,” Dolan said.

With the mapping nearly complete, the GO Phoenix, provided by Malaysia, will begin hunting in an area considered the likeliest crash site, based on an analysis of satellite data gleaned from the plane’s jet engine transmitter and a series of unanswered phone calls officials on the ground made to the plane.

The other two vessels, the Equator and Discovery, provided by Dutch contractor Fugro, are expected to join the hunt later this month.

Malaysia and Australia are contributing about $60m each towards the search.

The ships will use towfish, underwater vessels equipped with sonar that create images of the ocean floor. The towfish, which transmit data in real time, are dragged slowly through the water by thick cables up to 10km long. If something of interest is spotted on the sonar, the towfish will be hauled up and fitted with a video camera, then lowered again.

There will be between 25 and 35 people on each ship, and crews will probably work around the clock. The ships can stay at the search site for up to 30 days before they must head back to shore to refuel and resupply.

Dolan said, “We’re doing this primarily because there are families of 239 people who deserve an answer. We will give it every possible effort and we think our efforts will be really good – but there’s no guarantee of success.”