Air France 447 - Ocean Combed for Jet Data in Biggest Aviation Search
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RIO DE JANEIRO — Three ships and a nuclear-powered submarine are engaged in the most extensive marine search for black boxes from an airline accident in modern aviation history, air safety experts said Friday.
Search teams, with crew and equipment from the French and American navies, continued to scour the deep Atlantic waters on Friday, straining to hear an acoustic ping emitted from the flight data and cockpit recorders of Air France Flight 447, which crashed some 620 miles off the coast of northern Brazil in the early morning hours of June 1.
Veteran investigators said they could not recall a similar effort to locate a plane’s recorders; these could contain information that is critical to solving the mystery of the downed Airbus A330.
“I can’t think of any one event where there’s been more than one military naval organization out there hunting for them,” said Greg Feith, a former investigator at the National Transportation Safety Board.
The boats hunting for pings around the clock make up just part of the armada of sea and air craft involved in the search and recovery effort, which includes at least 11 ships, 10 planes and 2 helicopters from four countries. The Brazilian military has more than 1,000 personnel members devoted to the search.
It seems daunting and improbable to find tiny boxes in a huge ocean, especially with the precise crash site still uncertain, but searchers almost always recover them, air safety experts said.
Of 20 airplane crashes in water over the past 30 years, in only one case was neither recorder found during the crash investigation, said Curt Lewis, the president of Curt Lewis & Associates, a safety and risk management consulting firm. In one other case, one of the two recorders was recovered, and in two cases he was not able to determine whether they were ever found, he said.
But this search is more difficult than most. French investigators are scouring an area with a 50-mile radius and water depths exceeding 15,000 feet. Most airliner crashes over water have been along coastal waters or along the continental shelf, said Paul Hayes, air safety director of Ascend, an aviation consulting company in London.
“This is pushing the envelope,” he said. “Because of the depth of the water, this may be the accident where they fail to do it.”
Searchers are also pressed heavily for time. The boxes transmit signals for about 30 days before the signals start to fade. The batteries in the boxes on the Air France flight may have less than two weeks of life left before they go silent.
As the search for the boxes continued, Brazilian and French ships carried on with their recovery of bodies, debris and baggage. French authorities said Thursday that forensic teams were beginning the process of identifying the 50 bodies found so far.
Air France said Friday that it would begin making initial payments of $24,000 each to compensate families of the 228 victims of the accident. Under the terms of the Montreal Convention, relatives of people killed in aviation accidents are entitled to up to $154,000 in damages.
Brazilian medical authorities have begun autopsies of some of the crash victims. Some news reports have said that several of the bodies suffered fractures to their legs, hips and arms, leading some experts to suggest that the plane may have broken up in flight rather than when it struck the ocean.
But Paul-Louis Arslanian, the head of the French agency investigating the accident, BEA, said this week that it was still too early to draw definitive conclusions from the autopsies.
Finding the flight recorders could go a long way toward clearing up such doubts. As the French submarine slithers through the waters, two Dutch ships, contracted to French investigators, are towing a pair of torpedo-shaped hydrophones, essentially underwater ears, listening in stereo to help determine the direction of the pinger signal.
United States Navy personnel are assisting in the use of the hydrophones, which are attached by 23,000 feet of cable and on loan from the Navy, said Col. Willie Berges of the United States Air Force, chief of the United States military liaison office in Brazil.
The French ship is also equipped with equipment to listen for pings.
“We have a grid, and the submarine has a grid, and everybody is looking for that noise,” Colonel Berges said.
Once the ping is found, a French ship is set to send a robotic vehicle to the sea bottom to look for the recorders, he said. The French also have a minisubmarine with mechanical arms and a crew of three that can dive to 20,000 feet.
The Air France jet was equipped with memory chips, not tape, which are sealed in a hardened shell designed to protect them in crashes at sea.
“The whole problem here is, you don’t know where the crash site is,” Colonel Berges said. “Where the debris is is not where the crash site is.”
Still, given previous successful efforts, investigators remain hopeful that the recorders can be retrieved, even in the often-jagged ocean bottom. Mr. Feith, formerly of the National Transportation Safety Board, said that if the pingers did not lead the searchers to the boxes, they might later find the wreckage with the boxes inside.
“You have to hope the tail section stayed in a clump, rather than sling-shotting the boxes out somewhere,” he said.
In previous sea crashes, searchers overcame improbable circumstances to recover the boxes. When an Air-India Boeing 747 was destroyed by a bomb off the coast of Ireland in 1985, searchers found the boxes in about two and a half weeks, in 6,700 feet of water.
A Boeing 747 operated by Adam Air crashed in Indonesia in January 2007. Pingers were heard soon after, but recovery of the boxes took until August of that year because the water was more than 6,000 feet deep.
The case in which searchers failed to get either black box was that of a Boeing 727 owned by Faucett, a Peruvian airline, that crashed off Newfoundland in 1990, apparently because of lack of fuel, killing all 16 aboard.
Some boxes take longer than others to find. Searchers used sonar to recover the cockpit voice recorder from a South African Airlines Boeing 747 that crashed while traveling from Taiwan to Johannesburg in November 1987 — but not until 14 months later, and in 14,000 feet of water.
Alexei Barrionuevo reported from Rio de Janeiro, and Matthew L. Wald from Washington. Nicola Clark contributed reporting from Paris, and Mery Galanternick from Rio de Janeiro.
