Search crews hunting for the wreck of Malaysian Air Flight 370 may need to review the area of focus again because the absence of any surface debris suggests the correct location has still not been identified, said the German oceanographer who helped find the remains of Air France 447.
The optimism injected into the near-six week search after pinger signals were picked up may also prove ill-founded because the sounds could have come from sources other than the emergency beacons, said Peter Herzig, executive director of the Geomar Helmholtz Center for Oceanographic Research in Kiel, Germany.
“People are talking about how it’s difficult to find a needle in a haystack, but right now, we don’t know where the haystack is,” Herzig said in a telephone interview. “They need a much better definition of the crash area, they need to find debris, and then need some time to do some modeling given that these parts may have moved over several weeks now.”
The longest search for an aircraft in modern civil aviation has yet to result in the retrieval of any physical objects connected to the Boeing Co. 777 airliner, which went missing on March 8 with 239 people on board. The hunt has now settled on a zone in the southern Indian Ocean, with an unmanned submarine performing deep-sea scans of the seabed while ships and aircraft continue their surface missions to track down any pieces.
The underwater search has been “significantly narrowed,” with the use of acoustic analysis creating a more “more focused” area, Australia’s Joint Agency Coordination Centre said today. Herzig contends that there has been no corroborated, unequivocal evidence that the pinging sounds, which have now ceased, were indeed related to MH370.
“What you do is, you ask for radio silence in the ocean, and then you can check for pings” to avoid interference from other sources, which may not have occurred in this case, he said.
It was a Remus 6000 submarine owned by Herzig’s institute that located the wreckage from Air France 447 in April 2011, in collaboration with two others from Woods Hole Oceanographic Institute of Falmouth, Massachusetts. That cleared the way for remotely operated vehicles to go in and retrieve bodies and parts of the plane including the black boxes.
With all the planes and ships combing the Indian ocean for signs of debris, it’s unusual to draw a total blank, Herzig said. Given that the force of an aircraft hitting the ocean is similar to collision with concrete, this should leave at least some debris floating, as was in the case with the Air France 447 plane on route from Rio to Paris in 2009, he said.
Herzig’s institute, which has been doing searches for metal ores in international waters in the Indian ocean, isn’t involved in the underwater search. He said he spoke to the Malaysian ambassador two weeks ago about participating at a later point and is awaiting further information.
Two types of vehicles are used for deep-water searches. The first are automated underwater units, unmanned and untethered submarines dropped into the water for exploration missions using the classic lawn-mowing pattern in a criss-cross grid.
Once wreckage is located, remotely operated vehicles that are tethered to a surface ship by cables are lowered to the debris field. Herzig’s institute has two of the units.
The Air France search took two years to find the Airbus A330 on the bottom of the Atlantic Ocean, and salvage crews managed to retrieve the flight-data and voice recorders, which helped establish the cause of the crash that killed all 228 people on board the wide-body airliner.