No Trace of Flight 370 as Sub-Sea Search Halted for Three Months

May 27, 2014 1:07 pm ET

May 28 (Bloomberg) -- The search for wreckage of Malaysian Air Flight 370 will be suspended while investigators assemble a better map of the Indian Ocean, as satellite operator Inmarsat Plc said it can provide no more data on the plane’s flightpath.

A robot submarine will leave the suspected crash area 1,670 kilometers (1,000 miles) from Perth today, according to Australia’s Joint Agency Coordination Centre. The search will resume once a ship-based survey of the seabed has been completed in about three months, its air-accident investigator said in a statement, confirming that a final digital transmission from the jet most likely coincided with it running out of fuel.

No trace of the Boeing Co. 777-200 has been found in 81 days of searching from Thailand to the Southern Ocean, the longest hunt for a missing plane in modern aviation history. Data exchanges with an Inmarsat orbiter, including a last burst when fuel exhaustion seems to have interrupted the electrical supply, remain the only clue to where the Malaysian Airline System Bhd. plane went down with 239 people aboard on March 8.

“The complexities surrounding the search cannot be understated,” Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, said on its website. “It involves vast areas of the Indian Ocean with only limited known data and aircraft flight information.”

Data Log

Malaysia’s department of civil aviation yesterday released 43 pages of data logs showing more than nine hours of electronic communications between the 777 and the Inmarsat satellite.

The log includes seven digital “handshakes” with the plane that revealed its distance and direction of flight from the orbiter, and constitutes the entirety of information that Inmarsat has from the aircraft, the U.K. company said.

“We should be absolutely honest,” Inmarsat Vice President Chris McLaughlin said in an interview on Bloomberg Television’s “The Pulse” yesterday. “There is no more. We are working with what we have.”

The seventh and final handshake message from the Boeing at 00:19 universal time was a log-on request consistent with its satellite communication system powering up after interruption of the electrical supply, the ATSB said in an interpretation of the data logs. Estimates of fuel consumption also tally with the jet running dry close to the seventh arc.

Sonar Scans

China’s Zhu Kezhen naval ship is already scanning a 60,000 square kilometer area of the Indian Ocean, where the flight is believed to have ditched, to map the contours, depth and hardness of the seafloor, the ATSB said.

Ship-based sonar on the Chinese vessel and a commercial craft due to arrive next month will scan the zone, about the size of Sri Lanka, before a submersible is deployed again.

“We currently have very limited knowledge of the seafloor terrain facing the underwater search operation,” the bureau said. The initial survey “will give us crucial data to plan and conduct the intensified underwater search.”

The ocean depth in the area ranges between about 1,000 meters and 6,000 meters, according to the statement, reaching well beyond the 4,500-meter capability of the Bluefin-21 submarine that’s run deep-sea sonar searches since April 14.

MH370’s disappearance has baffled authorities because contact was lost less than an hour into a routine trip to Beijing from Kuala Lumpur. The jet vanished from civil radars while headed north over the Gulf of Thailand, then doubled back and flew over Peninsular Malaysia and on into the remote waters of the Indian Ocean, according to analysis of satellite signals.

Commercial Search

Inmarsat began measuring the time signals took to travel to and from its antennas as a way of locating missing aircraft after the 2009 Air France 447 crash, the ATSB said. The data log was published for reasons of “transparency,” McLaughlin said.

The Malaysian jet appeared to be descending at the time it sent its last signal to the Inmarsat satellite, the bureau said on its website. Studies completed at the time of the Air France accident suggest most aircraft in such crashes are found within 32 kilometers of their last known position, it said.

Asked if wreckage from MH370 would be found, McLaughlin said the search had been made tougher by extreme weather in the southern winter and the likely effect of the plane’s impact.

“There can be five or ten meter waves, extreme seas and storms, and if that aircraft did crash violently into the sea it may well have shattered into thousands of pieces,” he said.

Australia, in consultation with Malaysia, is willing to engage one or more commercial companies to undertake the next stage of the probe, Prime Minister Tony Abbott told an April 28 media conference. Searching the 60,000 square kilometer zone with a submersible will take up to 12 months, the ATSB said.

Investigators have scanned 4.6 million square kilometers of ocean, with 29 aircraft carrying out 334 flights and 14 ships afloat as part of the operation, Australia’s Deputy Prime Minister Warren Truss said at a May 5 press conference.

In its budget earlier this month, the country’s government set aside A$89.9 million ($83 million) in costs for the hunt over the two years ending June 2015.

--With assistance from Mark Barton in London.