More debris from the Air France Flight 447 has been found on Wednesday, but the whereabouts of its black box remained a mystery.
A seven-meter-long object and 10 other objects, some of them metallic, were spotted by the search planes at 3:40 a.m., said the Brazilian Air Force. A 20-kilometer-long oil track was spotted as well.
The items were found in four different points, spread over a five kilometers radius, 90 kilometers south of the place where the first debris were spotted.
According to the Air Force, the debris' position alone is no indication that the Air France plane suffered some sort of explosion in the air.
The plane which identified the debris, an Embraer R-99 model, has not spotted any bodies, but according to the Air Force's spokesman, Colonel Jorge Amaral, the authorities are still working with the possibility of finding survivors of the accident.
A total of 11 aircraft are involved in the search efforts, including a P-3 Orion model from the U.S. Air Force and a Falcon 50 model from the French Air Force. The remaining planes, including three Lockheed C-130 Hercules models, all belong to the Brazilian Air Force.
The French government also sent submarines, in an attempt to find the plane's Flight Data Recorder, which may help uncover the causes of the crash.
This may prove to be a difficult task, as the depth in the area surpasses 4,000 meters.
The French accident investigation agency said on Wednesday it was not hopeful that the black box of the Air France airliner would be found.
Speaking at the first news conference since the disappearance of the Air France flight 447 from Rio to Paris on Monday, Paul-Louis Arslanian, the director of France's air safety investigation agency, said he was "not optimistic" that the box would be found in the "deep sea and mountainous area."
"We might find ourselves blocked at some point by the lack of material elements," he said.
However, he noted that if rescuers do not find the black box, investigators should be prepared to continue the probe through other sources.
The black box, which contains voice and data recorders, is built to last 30 days at about 6,000 meters underwater.
Investigators are working with Air France, Airbus and meteorologists to determine what caused Air France Flight 447 to crash with 228 people on board into the Atlantic Ocean off the Brazilian coast on Monday.
The agency is expected to have an initial report on the disaster ready by the end of June, Arslanian said.
Describing the crash as the most serious in French aviation history, Arslanian said France will take charge of the investigations according to related international laws.
Asked what might have caused the crash, Arslanian said there were too many uncertainties regarding information obtained so far, plus the complexity of the sea area where the plane crashed, which all added to the difficulty of the investigations.
So far they could not determine whether the plane broke up in the air or upon impact with the sea, he said, warning that investigations were likely to last for a long time.
The studies of the plane's maintenance and other records showed no evidence that it had problems before takeoff from Rio de Janeiro on Sunday at 7 p.m. (2200 GMT), Arslanian said.
However, he declined to comment on an earlier Air France statement that the plane might have been hit by lightning.
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