Members of the Brazilian Pelican military squad prepare to depart from Campo Grande in Mato Grosso do Sul, Brazil, to help search for an Air France jet that disappeared over the Atlantic Ocean. (Walbe/Correio do Estado/Associated Press)

Large amounts of debris found floating in the Atlantic confirm an Air France plane that disappeared while flying from Brazil to Paris crashed into the ocean, Brazil's defence minister said Tuesday.

Nelson Jobim told a news conference that the five-kilometre path of wreckage found earlier in the day is "without a doubt" from the Airbus A330, which was carrying 228 people when it vanished over the Atlantic Ocean after leaving Rio de Janeiro on Sunday night.

Brazilian search planes have spotted possible debris from Air France Flight 447 about 650 kilometres northeast of the Archipelago of Fernando de Noronha. (CBC)Searchers in planes spotted the debris — including an orange life-vest, a small white piece of metal and what is believed to be an airliner seat — at about 1:30 a.m. local time (12:30 a.m. ET) Tuesday.

There were no signs of any lifeboats, survivors or bodies.

French officials have said there is little chance of finding any survivors. Police are studying passenger lists and preparing to take DNA from passengers' relatives to help identify any retrieved remains.

Among the 216 passengers and 12 crew was Brad Clemes, 49, a Coca-Cola executive who was born and raised in Guelph, Ont., and lived in Belgium.

If there are no survivors, as feared, it would be the world's deadliest commercial airline disaster since Nov. 12, 2001, when an American Airlines jetliner crashed in the New York City borough of Queens during a flight to the Dominican Republic, killing 265 people.

'Race against the clock' to find black boxes

This photo taken Tuesday shows a French army air crewman aboard an Atlantic Model 2 aircraft, which took off from a French air base in Dakar, Senegal, monitoring the presumed crash site of a missing Air France passenger jet. (Associated Press/ECPAD/French Defence Ministry)Military aircraft and ships from France, Brazil and Senegal are continuing to sweep the area, searching for more signs of the plane. Authorities also asked commercial vessels to aid the search, and the United States agreed to use satellite imagery to help locate the wreckage.

"The search-and-rescue folks are very good about being able to pick up small objects in the water," said John Cox, an airline safety consultant. "They're highly trained for this."

The size of the debris field will give some indication as to whether the airplane struck the water in one piece or broke apart in flight, Cox said.

Aviation experts have said it is unusual there was no human or automatic distress message sent from the plane and that no emergency beacons transmitted.

Finding the plane's flight-data recorder will allow officials to begin to determine what happened, said Doug Moss, an aviation expert who teaches at the University of Southern California.

It is a "race against the clock" to find the plane's two black boxes, which emit signals for up to 30 days, said French Transportation Minister Jean-Louis Borloo Tuesday.

'Succession of extraordinary events'

This undated picture taken at Houston's George Bush Intercontinental Airport shows the Air France Airbus 330-200 that has been reported missing. (Airteamimages.com/Associated Press)The immense area of open ocean between northeastern Brazil and western Africa has depths reaching 4,570 metres. But the technology exists to retrieve any relevant parts from the bottom of the ocean if the plane is found, Cox said.

Officials believe that "there really had to be a succession of extraordinary events to be able to explain this situation," Borloo said.

Air France received an automatic message from Flight 447 signalling an electrical circuit malfunction about four hours into the flight, at 10 p.m. ET on Sunday. The message came shortly after the flight crossed "through a thunderous zone with strong turbulence," Air France officials said.

Some officials have speculated the plane may have been struck by lightning, but aviation experts have said that should not have been enough to bring down the aircraft.

Other potential causes include shifting winds and hail from towering thunderheads, a massive mechanical failure or a combination of other factors.

Meteorologists speculated Tuesday that the aircraft might have faced winds as strong as 160 km/h created from a series of thunderstorms along the flight path.

Pentagon officials told The Associated Press that American authorities have not seen any evidence suggesting terrorism or foul play.

With files from The Associated Press