France's chief air accident investigator said Thursday that he's confident about recovering data from the two flight recorders of an Air France plane that crashed into the Atlantic almost two years ago.
BEA head Jean-Paul Troadec told reporters that the so-called black boxes "appear to be in good shape."
"I'm fairly confident" they can be used, he said.
The man in charge of the BEA's engineering department, Christophe Menez, said it would take at least three days to learn with certainty whether information contained on the flight data recorder and the cockpit voice recorder can be recovered to help unlock the cause of the crash.
Other parts of the plane discovered in the ocean's depths _ some not yet brought to France _ can also contribute to learning why Flight 447 from Rio de Janeiro to Paris plunged into the Atlantic on June 1, 2009, killing all 228 people aboard.
Deciphering all the information can take weeks or months, said Alain Bouillard, director of the investigation.
"This process isn't counted in days. It is counted in weeks or months," he said.
The data recorders arrived under high security at BEA headquarters outside Paris on Thursday.
Dozens of police stood by as two white packaging boxes were removed from a van. The recorders had traveled in a French Navy boat from the crash site to French Guiana, where they were put on a plane.
The seven memory cards in each data recorder will be extracted, cleaned, dried and tested to see if they still work. If so, data will be copied onto BEA's computers.
"If the card is in good shape it can be read in a couple hours," Menez said. If damaged, it is impossible to say how long it might take to try to cull information from it, he added.
The officials said BEA will provide an update on the data recovery operation Monday.
Meanwhile, forensics experts from France's police force will be examining tissue samples from two bodies that were raised from the plane's site earlier this month. Francois Daoust, the head of the French Forensic Institute, said experts will determine whether there is any useable DNA in the samples that could help identify the victims.
"The problem is these bodies have spent two years at 4,000 meters under 400 bars of pressue," Daoust said. That may have rendered the DNA unusable for identification purposes, in which case no further bodies will be raised from the ocean floor.
If useable DNA is found to have withstood the long period underwater, more bodies may be brought up, but this will be decided on a case by case basis, Daoust said.
Searchers on the Ile de Sein ship that is conducting the search and retrevial operation have observed around 50 bodies amid the plane's wreckage, Troadec said.
So far the searchers have not found the plane's speed sensors, known as Pitot tubes, which investigators say probably played a role in the crash.
The wreckage was discovered April 3 after nearly two years of searching a remote swathe of the mid-Atlantic between Brazil and West Africa.
Finding the cause took on new importance in March when a French judge filed preliminary manslaughter charges against Air France and the plane's manufacturer, Airbus. Experts say the flight data and voice recorders are indispensible for determining what was at fault.
The accident was the worst diaster in Air France's history. The flight from Rio de Janeiro to Paris slammed into the Atlantic northeast of Brazil after running into an intense high-altitude thunderstorm.
Automatic messages sent by the Airbus 330's computers showed the aircraft was receiving false airspeed readings from sensors known as pitot tubes. Investigators have said the crash was likely caused by a series of problems and not just a sensor error.
On the web: http://www.bea.aero/en/index.php
Greg Keller can be reached at http://twitter.com/Greg_Keller