SAO PAULO — A Dutch ship towing a high-tech listening device from the U.S. Navy was set to troll the Atlantic on Sunday in search of data and voice recorders that investigators say are key to determining what caused an Air France jet to crash in the Atlantic with 228 people on board.
The Navy device, called a Towed Pinger Locator, will try to detect emergency audio beacons from Flight 447's black boxes, which could be lying thousands of feet below the ocean surface.
Without the recorders, it may be impossible to ever know what caused the Airbus A330 to crash several hundred miles off Brazil's northeastern coast on May 31.
The device is capable of searching to a depth of 20,000 feet.
U.S. Air Force Col. Willie Berges said the device would start operating as soon as searchers were sure it would not interfere with a French nuclear submarine already searching for the black boxes.
Another Dutch ship carrying a second listening device is scheduled to arrive by today.
The ships will tow the locators in a grid pattern while 10-person teams watch for signals on computer screens, Berges said.
The search area includes some of the deepest waters of the Atlantic — and in two weeks the boxes' signals will begin to fade.
In Paris, the head of Airbus' parent company said there was probably more than one reason for the crash. "In such an accident, there is not one cause," EADS CEO Louis Gallois said. "It's the convergence of different causes."
"It's essential for everybody to know what happened and we know that it's not easy. I hope we will find the black box."