Titanic-Exploring Sub to Aid Flight 447 Search

A mini-submarine that explored the undersea wreckage of the Titanic is being whisked across the Atlantic to help retrieve the flight recorders of Air France Flight 447.

The French marine research institute Ifremer said Thursday it has pulled the ship Pourquoi Pas? (Why Not?) off a research mission in the Azores to help find the remains of the Airbus plane. Flight 447 disappeared Sunday night en route from Rio de Janeiro to Paris after flying into a dangerous band of thunderstorms over the Atlantic Ocean.

On board the research ship is the Nautile, an 8-meter (26-foot) long deep ocean submarine that has made multiple dives to the Titanic and a remote-controlled robot called Victor 6000.

"The priority for us is to find the black boxes," said Vincent Rigaud, head of Ifremer's underwater system department. "We will do everything we can to find them."

Search teams have a month to locate the plane's two black boxes -- the cockpit voice and flight data recorders -- before they stop emitting signals. They could be scattered nearly anywhere across a vast undersea mountain range below the surface of the ocean.

The French ship will dock in the Cape Verde Islands off Africa's western coast on June 8 to pick up equipment -- including a hydrophonic microphone -- and personnel. Manned by 25 sailors and a team of 20 specialists, the ship should reach the site off the northeast coast of Brazil where military aircraft are searching for remains of the plane by June 11 or 12, Rigaud said.

The supersensitive microphone will then be deployed to depths of 500 meters (1,640 feet) above the seabed to locate the continuous "pinging" signals emitted by the black boxes, which are believed to up to 13,000 feet (4,000 meters) below the sea.

"It's not going to be easy," Rigaud said. "The zone is very large. It's the first time we are trying to find black boxes so deep."

If the microphone detects the pinging, the mini-sub Nautile and the robot Victor will be deployed.

The Nautile can carry a three-man crew jammed into a nearly 10-foot (2.1-meter) diameter cabin. Three tiny portholes allow the crew to peer outside for the black boxes, which are actually bright orange and covered in reflective tape.

The vessel is also equipped with a panoramic sonar, capable of detecting signals up to 200 meters (218 yards) to the side, and several cameras. The black boxes could be retrieved by two mechanical arms. The Nautile made several dives to the Titanic in 1987, 1993, 1994, 1996 and 1998, including when the wreck was first discovered. It has also been used to recover wreckage from several planes that went down in the ocean.

The Victor is attached by electrical and optical cables to the Pourquoi Pas? and is operated by staff on the boat.

Still, the head of France's accident investigation agency, Paul-Louis Arslanian, has said he was "not optimistic" that officials would ever recover the black boxes from the plane. Experts have also told The Associated Press that layers of warm and cold water, with differing salinity, can affect the signals emitting from the black boxes, making them harder to find.

In 1998, search teams struggled to find black boxes from an Indonesian Boeing 737 that plunged into the sea on New Year's Day, killing all 102 people on board. The Adam Air plane was flying from the island of Java to an airport in eastern Indonesia when it spiraled from the sky from an altitude of 33,000 feet (10,000 meters).

The pings emitted by the recorders were located three weeks later by the U.S. Navy's oceanographic survey ship Mary Sears at a depth of over 6,500 feet (2,000 meters). But it took another eight months before the U.S. marine salvage firm Phoenix International recovered the boxes.

Although the wreckage of Air France Flight 447 could end up at a greater water depth, the Adam Air salvage showed that black boxes deep underwater can be successfully recovered if their position is precisely fixed before their beacons stop functioning.