Atlantic debris is missing flight 447

Brazilian officials have confirmed that wreckage seen floating in the Atlantic Ocean off the Brazilian coast comes from the Air France plane that disappeared on Sunday night. But the chances of recovering the black box, now thought to be at the bottom of the ocean, are slim, according to investigators.

Air force spotter planes (such as the one pictured above taking off from Cape Verde) discovered a three mile path of debris, including oil slicks and metallic objects, in the ocean around 400 miles north of the archipelago of Fernando de Noronha. Brazil's defence minister, Nelson Jobim, announced it came from the doomed flight AF447, he said the discovery "confirms that the plane went down in that area."

Pilots reported that there were no signs of life, but several ships are on their way to the area. Two commercial ships have reached the site to assist in the search and French naval vessels have also been dispatched.

French officials agree there is no doubt that the debris is from the missing plane. However, they fear the black box, which could reveal what actually happened to the doomed plane after it encountered thunderstorms and was apparently hit by lightning, may never be recovered.

The cockpit voice and data recorders can send signals for about 30 days, but it is thought they may be at a depth of up to 3,000m and Paul-Louis Arslanian, chief of the French civil aviation ministry's bureau of investigation, said he was "not optimistic" at the prospect of finding the boxes because of the terrain under the sea.

He said: "Without them it will be very difficult to reach established fact, but we can reach a possible explanation."

The only concrete clues so far as to what happened to the Airbus A330-200, which had 228 passengers and crew on board, are contained in a dozen automated technical messages to Air France's operations department. The messages, which began when the plane was four hours into its 11-hour flight and heading for a storm, came over a period of about 15 minutes. They told Air France that several electrical systems had broken down.

If no survivors are found, it will be Air France's worst ever accident. The last was in July 2000 when a Concorde bound for New York crashed 60 seconds after taking off from Charles de Gaulle airport. All 109 people on board were killed. 

WHAT THE EXPERTS ARE SAYING

• Jim Morris, a senior associate at Stewarts Law: "It could be that if the A330 is more vulnerable to electromagnetic interference, it could have caused the pilots to lose control of the aircraft during severe turbulence. The indications from the aircraft's datalink system are that there was a loss of electrical systems in a very short space of time, which indicates that there was a catastrophic failure."

• French military official Captain Christophe Prazuck: "While formal confirmation must still be obtained by recovering debris and carrying out technical analysis, there is no longer any room for doubt."  

• Commander Ronaldo Jenkins, safety coordinator for Brazil's airline association: "To find the plane, you'll need ships equipped with a special sonar, and possibly also rescue submarines - it's an enormous undertaking."

• Pierre Sparaco of the French Air and Space Academy: "Lightning alone is not enough to explain it. There must be a missing link. Accident investigators talk always of a sequence of catastrophic events, and 'sequence' is the key word."

• David Learmount of Flight International magazine: "Modern aircraft are so reliable and have so many backups for every system that a single electrical fault, or even the loss of an entire circuit, would be easily dealt with - if that were all that occurred... If the last message from the plane has been correctly interpreted as a short circuit, that raises the spectre of an electrically caused fire, and fire is always serious in an aircraft."

• Douglas Ferreira Machado, head of investigation for Brazil's Civil Aeronautics Agency: "It could be a long, sad story. The black box will be at the bottom of the sea."

• Henry Margusity, senior meteorologist for AccuWeather.com: "Tropical thunderstorms tower so high that it can be impossible to fly over them. At the altitude it was flying, it's possible that the Air France plane flew directly into the most charged part of the storm." ·