AIR FRANCE flight 447

An airplane seat, a fuel slick and pieces of white debris scattered over three miles of open ocean marked the site in the mid-Atlantic Tuesday where Air France Flight 447 plunged to its doom, Brazil's defense minister said.

Brazilian military pilots spotted the wreckage, sad reminders bobbing on waves, in the ocean 400 miles northeast of these islands off Brazil's coast. The plane carrying 228 people vanished Sunday about four hours into its flight from Rio de Janeiro to Paris.

"I can confirm that the five kilometers of debris are those of the Air France plane," Defense Minister Nelson Jobim told reporters at a hushed press conference in Rio. He said no bodies had been found and there was no sign of life.

The effort to recover the debris and locate the all-important black box recorders, which emit signals for only 30 days, is expected to be exceedingly challenging.

"We are in a race against the clock in extremely difficult weather conditions and in a zone where depths reach up to 7,000 meters (22,966 feet)," French Prime Minister Francois Fillon told lawmakers in parliament Tuesday .

Brazilian military pilots first spotted the floating debris early Tuesday in two areas about 35 miles (60 kilometers) apart, said Air Force spokesman Jorge Amaral. The area is not far off the flight path of Flight 447.

The cause of the crash will not be known until the black boxes are recovered — which could take days or weeks. But weather and aviation experts are focusing on the possibility of a collision with a brutal storm that sent winds of 100 mph straight into the airliner's path.

Rescuers were still scanning a vast sweep of ocean. If no survivors are found, it would be the world's worst civil aviation disaster since the November 2001 crash of an American Airlines jetliner in the New York City borough of Queens that killed 265 people.