New search about to start for black boxes of Air France jet that disappeared in mid-Atlantic

New search starting for Air France black boxes

RECIFE, Brazil — The lead investigator of last year’s Air France jetliner crash that killed 228 people off the coast of Brazil said Thursday he hopes a third search for debris and flight and data recorders will be successful and help authorities determine what happened.

The 30-day operation, to begin next week after search ships sail for the mid-Atlantic on Sunday, will scour an area of seabed only one-tenth that combed in the two previous attempts, Jean-Paul Troadec, chief of the BEA French investigation agency, said at a news conference in northeastern Brazil.

The smaller area was the result of a collaborative effort by scientists, including from the U.S.-based Woods Hole Oceanographic Institution in Massachusetts, to reconstruct the trajectory of the Airbus 330’s debris and the time the wreckage was found, giving investigators a better idea of where to look, Troadec said.

“We think we have a good chance of finding the wreckage,” he said.

Officials say that locating the flight data and voice recorders is crucial, since the 1,000 pieces of wreckage already recovered have provided no concrete information as to what caused the jet to crash June 1, killing everyone aboard.

The devices contain recordings of cockpit conversations and various data readings from the aircraft.

Without that information, investigators will probably never know why the jet bound from Rio de Janeiro to Paris flew straight into huge thunderstorms that other trans-Atlantic flights on similar routes took pains to avoid that day. Based on information gathered so far, investigators believe the plane was intact when it crashed into the ocean.

Troadec said the investigation so far has “shown that without finding the recorders that this investigation could never be conclusive and this accident could remain largely unexplained.”

The latest search will employ two ships, one of which will deploy three sonar-equipped robot submarines weighing more than 5 metric tons each to search the seabed. The other will use sonar machines dragged on cables underwater to pore over the 770-square mile (2,000-square kilometer) target area.

Troadec said the wreckage is likely located on a rough, mountainous seabed, perhaps as many as 13,100 feet (4,000 meters) below the surface.

“These mountains are not trivial — it’s as rugged as the foothills of the Rockies down there and can get a lot worse than the Rockies — but there are some wide open spaces, valleys in there, that look very promising,” said David Gallo, director of special projects for Woods Hole.

William Waldock, who teaches air-crash investigation at Embry-Riddle Aeronautical University in Prescott, Arizona, said that even if a main debris field is found, it does not mean the flight recorders can be located.

“A lot will depend on whether the recorders are still attached to a larger structure or if they separated from it during impact,” he said. “Conceivably, they are looking for something that is a couple of feet long and 8 inches wide. Chances of finding something like that under 13,000 feet of water are not good.”

Waldock said the effort “is probably the most difficult search I’ve seen simply because of the size of the area and the bottom configuration.”

“But if they don’t look, their chances are zero,” he added.

Automatic messages sent by Flight 447’s computers just before it crashed show it was receiving false airspeed readings from sensors known as Pitot tubes. Experts have said running into a violent storm at either too slow or too fast a speed at high altitudes can be dangerous.

Investigators have insisted the crash was likely caused by a series of failures and not just the Pitot tubes.

The new euro10 million ($13.3 million) search is jointly financed by Airbus and Air France, and comes after original search efforts last year that cost about euro9 million. The U.S. Navy and the National Transportation Safety Board will help, along with private companies and accident experts from Britain, Germany, Russia and Brazil.

The life span of “pingers” attached to the plane’s recorders is only about a month, but officials say submarines and boats equipped with sonar gear can find the wreckage from the jet even without such signals.

Gallo said the operators of the sonar systems being used have previously pinpointed objects as small as oil barrels and metal wire measuring about 4 inches (10 centimeters) in diameter. Because many of the plane’s parts, including the recorders, are made of metal, they stand out compared to rocks on the sea floor.

If debris fields are found, the two ships will hone in on those areas and search for the recorders. Other wreckage may also be lifted to the surface with cables or by remote-controlled submarines.

There could be “multiple items, like fuselage, landing gear, the cockpit,” said John Ric Sasse, a civilian U.S. Navy search and recovery specialist involved in the effort. “All of this could be a large variety of items spread out over a large area, and once you have found it there are just the mechanics of recovery.”

The second search for the recorders ended in August.

Investigators said 50 bodies were recovered in the first two searches. Troadec said searchers are prepared to recover any more remains that may be found.

Associated Press Writer Bradley Brooks in Rio de Janeiro contributed to this report.