On Monday an "ocean of debris" surrounded divers recovering wreckage and bodies from Air France flight 447 in the Atlantic Ocean, and searchers today recovered the stabilizer from the plane's tail, according to the Brazilian Navy.
It's still unclear if the jet broke up in the air or on impact. But former crash investigator Gregory Feith said they may be able to tell from the tail.
"If it's on the backside or the furthest up the debris chain, then there's a high probability that could have been one of the first components that came off the airplane," said Feith.
The evidence is being flown to the Brazilian island of Fernando de Noronha, some 400 miles off the country's coast.
The flight crashed with 228 people onboard en route from Rio de Janeiro to Paris after departing on May 31. As the hunt for clues picks up pace, searchers are scouring an area 45 miles from where plane last sent a burst of automated messages documenting failures in the flight's systems.
In the grim recovery effort, human remains will provide clues about what may have gone wrong.
Frank Ciaccio, who supervised wreckage recovery for Egypt Air and other underwater accidents while working for the National Transportation Safety Board, said full forensic examinations are "not going to solve all the answers," but can still provide crucial information.
"Identifying them is going to be the No. 1 priority," said Ciaccio, forensics specialist and vice president of commercial services for Kenyon International Disaster Management Services. "No. 2 priority is going to be to document any injuries the body sustains so that they can add to the investigation, and help with putting a final picture together."
"It's not going to solve why this plane went down, but it'll give something back to the family members that do find their loved ones right now, and it'll give some hope to the other ones that hopefully they will be able to recover more of their loved ones," he added.
A French nuclear submarine is expected to arrive Wednesday to look for the plane's black boxes.
On Monday, the U.S. Navy sent a team and two underwater, high-tech listening devices used in military crashes. The devices are towed behind a boat to listen for the "pinging" signal emitted from the plane's cockpit voice recorder and flight data recorders. They can detect the black boxes at depths of 20,000 feet and have been used in military accidents.
Those recorders could also tell investigators whether the pilots tried to turn back toward land. Investigators believe may have been the case, based on the location of the wreckage and bodies.
"The black boxes are really going to give a lot of information, a good 90 percent of the information," Ciaccio said. "These are all pieces of the puzzle. It would be like an incomplete puzzle with the black boxes not being recovered."
The boxes' locator signals may last just 21 more days.
ABC News' Zoe Magee, Ammu Kannampilly, Renata Araujo, Sonia Gallego, Joe Goldman, Christel Kucharz, Luis Martinez, Phoebe Natanson, Fabiola Antezana, Gabriel O'Rorke, Samira Parkinson-Smith, Kirit Radia and Christophe Schpoliansky, Reuters and The Associated Press contributed to this report.