The missing Malaysian passenger jet can’t be found in a remote area of the Indian Ocean that’s been searched by submarine for the past two months, Australian authorities said today.
An autonomous sub yesterday finished scouring more than 850 square kilometers (330 square miles) of seafloor “within its depth limits” around where acoustic pings similar to those emitted by aircraft black boxes were detected in early April, the Joint Agency Coordination Centre said in a e-mailed statement.
“The area can now be discounted as the final resting place of” Malaysian Airline System Bhd. (MAS) Flight 370, the JACC said.
Today’s announcement, which didn’t identify the exact areas searched, left open questions about the effort and didn’t rule out that the plane is in a part of the search area that can’t be reached.
Two people with knowledge of the search said the zone included waters too deep for the Bluefin-21 sub to reach and, therefore, new equipment must be obtained to access those areas when work resumes later this year.
The deep-sea search for the airplane, a Boeing Co. (BA:US) 777-200, was called off for about three months yesterday so investigators can assemble a more accurate map of the ocean floor in the region about 1,670 kilometers northwest of Perth, Australia. That’s the area where an analysis of satellite transmissions suggests the plane splashed down after running out of fuel, according to the JACC.
No trace of the aircraft has been found since it disappeared on March 8 with 239 people on board while en route to Beijing from Kuala Lumpur.
The Bluefin-21, named Artemis by its U.S. Navy operators, has been studying the seabed using side-scan sonar in the vicinity of four acoustic signals heard on April 5 and April 8.
It was able to reach depths of about 5,000 meters (3.1 miles), according to Jim Gibson, general manager of Phoenix International Holdings Inc., the U.S. company performing the search under contract to the Navy.
The sonar technology was used to locate Air France Flight 447 aircraft in the Atlantic Ocean, and can pick out objects less than a meter in size.
Investigators in Australia and elsewhere around the world continue to study the acoustic signals recorded in the Indian Ocean in early April, one person familiar with the search said. Each of the two crash-proof black box recorders on the plane were equipped with a device that emits a once-a-second ping that is outside the range of human hearing.
The first two recordings from April 5 were at a frequency of 33.331 kilohertz, which is slightly below the expected frequency of 37.5 kilohertz, according to an April 9 briefing by Angus Houston, who is leading the JACC.
Even though the frequencies aren’t precise and the search has covered most of the area around where the sounds were recorded, investigators aren’t ready to declare that the pingers didn’t come from the plane’s black boxes, the person said.
Michael Dean, the U.S. Navy’s deputy director of ocean engineering, said in an interview with CNN yesterday the lack of wreckage suggests the original pings probably came from the search vessel itself or some other source.
“I’d have to say at this point based on all of the imagery data that we’ve collected and looked at, if that black box were nearby we would have picked it up,” he told CNN. “We may very well have been in the wrong place.”
Dean’s comments were “speculative and premature,” Christopher Johns, a U.S. Navy spokesman, said in an e-mail. It’s up to the Australians, who are acting as the lead of the search, to release information on the pingers, Johns said.
Today’s announcement from the Australian JACC didn’t discuss the analysis of the pingers.
The disappearance of Malaysia Air Flight 370 has baffled authorities because contact was lost less than an hour into a trip to Beijing. The jet vanished from civil radar while headed north over the Gulf of Thailand, then doubled back and flew over Peninsular Malaysia and into the remote waters of the Indian Ocean, according to analysis of satellite signals.
Data exchanges with an Inmarsat Plc (ISAT) satellite, including a last burst when fuel exhaustion seems to have interrupted the electrical supply, remain the chief clues to where the plane went down.
On May 27, Malaysia’s department of civil aviation 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 — all the information that Inmarsat has, the U.K. company said.
“The complexities surrounding the search cannot be understated,” Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, said in a May 26 statement on the agency’s website. “It involves vast areas of the Indian Ocean with only limited known data and aircraft flight information.”
Investigators have scanned 4.6 million square kilometers of ocean surface, 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.
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