The Airbus 330 crashed into the Atlantic en route from Rio de Janeiro to Paris on June 1, killing all 228 people onboard. The crash site is more than 900 miles off Brazil's northeastern coast.
Now the 328-foot ship Pourquoi Pas is focused on finding more of the plane's wreckage in hopes that the black boxes might be recovered amid the debris, according to BEA, the French agency investigating the crash.
The Pourquoi Pas is operated jointly by the French Navy and the French Research Institute for Exploration of the Sea. It has a manned submarine, the Nautile, a remote-controlled robot, the Victor 6000, and special sonar.
The Nautile was previously involved in searching for the wreckage of the Titanic.
The BEA statement confirmed that Flight 447's cockpit voice and flight data recorders were no longer emitting any signals. The black boxes are built to send emergency "pings" for at least 30 days before they fade away.
The French agency also welcomed Airbus' committment to help fund a third phase of the search over a wider area, should that be necessary.
Tons of debris from the plane was brought to a French military research center for further examination earlier this month. A total of 640 parts of the plane have been recovered from the Atlantic Ocean - including a nearly intact tail, an engine cover, uninflated life jackets, seats and kitchen items.
A total of 50 bodies were recovered before Brazilian authorities called off the search for debris and bodies.
A preliminary report into the crash said the plane hit the ocean intact and belly first at a high rate of speed. But without the flight recorders, investigators may never know fully what happened. Investigators have announced no signs of explosion or terrorism.
The search continued as Airbus announced Thursday that it had delivered the 1,000th aircraft from the A330/A340 Family. The aircraft, an A330-300, was handed over to Thai Airways International (THAI) at a special ceremony in Toulouse.