Officers recover debris belonging to the Air France Flight 447

Officers recover debris belonging to the Air France Flight 447 (Photo released by Brazil's Air Force)

Some members of the crash victims' families said that without a clear cause to blame the accident on, the interim report held little significance.

Marco Tulio Moreno Marques, a 43-year-old lawyer in Rio de Janeiro, lost both his parents in the crash. He did not bother watching the French investigators' public presentation, saying that without the black boxes, he was skeptical of any findings.

"I think it is difficult that they will ever find out what happened," he said. "They can say a flying saucer hit the plane, but if they don't find the black boxes we will never know for certain what happened."

Kieran Daly, editor of Air Transport Intelligence, said although investigators seem to know very little about what happened due to "a horrendous lack of evidence," it is significant that the plane landed the right way up.

"It suggests they were in some kind of flight attitude," he said.

But he warned that "without finding the black boxes it's going to be phenomenally difficult, maybe impossible, to determine what happened."

Bouillard said life vests found among the wreckage were not inflated, suggesting passengers were not prepared for a crash landing in the water. The pilots apparently also did not send any mayday calls.

He said there was "no information" suggesting a need to ground the world's fleet of more than 600 A330 planes as a result of the crash.

"As far as I'm concerned there's no problem flying these aircraft," he said.

Air France said all elements of the investigation "will be fully and immediately taken into account by the airline" and that it is continuing to cooperate with the investigators with "a commitment to total transparency with regard to the investigators, its passengers and the general public."

The black boxes - which are in reality bright orange - are resting somewhere on an underwater mountain range filled with crevasses and rough, uneven terrain. Bouillard said the search for them has been extended by 10 days through July 10, while his investigation would run through Aug. 15.

Bouillard said French investigators have yet to receive any information from Brazilian authorities about the results of the autopsies on the 51 bodies recovered from the site.

But a spokesman for the Public Safety Department in Brazil's Pernambuco state - in charge of the autopsies - denied that.

"French medical examiners are working together with Brazilian medical examiners and they have full access to all the information obtained from autopsies," the spokesman said on condition of anonymity according to department rules.

Families of the victims met with officials from BEA, Air France and the French transport ministry before the report was released. An association of families addressed a letter to the CEO of Air France, Pierre-Henri Gourgeon, demanding answers to several questions about the plane.

Investigators should have an easier time recovering debris and black boxes in the crash of a Yemeni Airbus 310 with 153 people on board that went down Tuesday just nine miles (14.5 kilometers) north of the Indian Ocean island-nation of Comoros.