Two officials say investigators in an Air France jet crash are looking at whether speed data instruments malfunctioned.

The officials, who have knowledge of the investigation, say an iced-over external probe or a bad speed sensor may have fed inaccurate data to onboard computers controlling the jet. They spoke on condition of anonymity because they weren't authorized to discuss the case.

Brazil's Navy and Air Force, meanwhile, issued statements saying that despite earlier reports by the military, no wreckage had been recovered from the Airbus A330, which went down off the country's northeastern coast, killing all 228 people aboard. It is the world's worst aviation disaster since 2001.

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Air France has told families of passengers on the jetliner that it broke apart and they must abandon hope that anyone survived, a grief counselor said.

Air France's CEO Pierre-Henri Gourgeon told families in a private meeting that the plane broke apart either in the air or when it slammed into the ocean and there were no survivors, according to Guillaume Denoix de Saint-Marc, who was asked by Paris prosecutors to help counsel relatives. The plane, carrying 228 people, disappeared after leaving Rio de Janeiro for Paris on Sunday night.

Investigators were relying heavily on the plane's automated messages to help reconstruct what happened to the jet as it flew through towering thunderstorms. They detail a series of failures that end with its systems shutting down, suggesting the plane broke apart in the sky, according to an aviation industry official with knowledge of the investigation. He spoke on condition of anonymity Wednesday because he was not authorized to discuss the crash.

The French agency investigating the crash says the automatic messages received from the plane have failed to show exactly how fast the aircraft was flying.

The Accident Investigation Agency says only two findings have been established. One is that the series of automatic messages sent from Flight 447 were "incoherent" regarding the plane's speed. The other is that the plane's route Sunday night was spotted with stormy, unstable weather.

The agency warned against any "hasty interpretation or speculation" about the crash. The French newspaper Le Monde had reported, without naming sources, that the Air France plane was flying at the wrong speed.

According to the Le Monde report, manufacturer Airbus was set to issue recommended speeds for flying the A330 aircraft during poor weather conditions. Neither Airbus nor the French air accident investigation agency would comment on the report of recommendations, known as an Aircraft Information Telex.

The pilot of a Spanish airliner flying near where the Airbus is believed to have gone down reported seeing a bright flash of white light that quickly plunged to the ocean, said Angel del Rio, spokesman for the Spanish airline Air Comet.

"Suddenly, off in the distance, we observed a strong and bright flash of white light that took a downward and vertical trajectory and vanished in six seconds," the pilot wrote in a report for the airline and Spanish civil aviation authorities, del Rio told the AP.

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The Spanish plane was flying from Lima, Peru to Madrid. The pilot said he heard no emergency calls from the plane.

"What is clear is that there was no landing. There's no chance the escape slides came out," said Denoix de Saint-Marc, who heads a victims' association for UTA flight 772, shot down in 1989 by Libyan terrorists.

No survivors makes Flight 447 Air France's deadliest plane crash and the world's worst commercial air accident since 2001.

Brazil's Defense Minister Nelson Jobim said debris discovered so far was spread over a wide area, with 140 miles separating pieces of wreckage they have spotted. The overall zone is roughly 400 miles northeast of the Fernando de Noronha islands off Brazil's northern coast, where the ocean floor drops as low as 22,950 feet below sea level.

Brazilian military planes located new debris from Air France Flight 447 Wednesday, after spotting an airline seat and oil slick a day earlier. But Prazuck said Thursday that French planes had made six missions over the area and have yet to spot any wreckage.

"As of today French planes have not found any debris that could have come from the Air France Airbus that disappeared. There have been radar detections made by the AWACS (radar plane) ... and each time these signals have not corresponded to debris," Prazuck said.

He said, however, French teams have been searching in different places and at different times from the Brazilian search teams.

Heavy weather delayed until next week the arrival of deep-water submersibles considered key to finding the black box voice and data recorders that will help answer the question of what happened to the airliner.

The "Pourquoi Pas," a French sea research vessel carrying manned and unmanned submarines, is heading from the Azores and will be in the search zone by June 12, Prazuck said. The equipment includes the Nautile, a mini-sub used to explore the undersea wreckage of the Titanic, according to French marine institute Ifremer.

"The clock is ticking on finding debris before they spread out and before they sink or disappear," Prazuck said. "That's the priority now, the next step will be to look for the black boxes."

The lead French investigator has questioned whether the recorders would ever be found in such a deep and rugged part of the ocean.

The plane's last automated messages detail a series of failures that end with its systems shutting down, suggesting the plane broke apart in the sky, according to an aviation industry official with knowledge of the investigation, who spoke on condition of anonymity because he was not authorized to discuss the crash.

The pilot sent a manual signal at 11 p.m. local time Sunday saying he was flying through an area of black, electrically charged cumulonimbus clouds that come with violent winds and lightning.

Ten minutes later, a cascade of problems began: Automatic messages indicate the autopilot had disengaged, a key computer system switched to alternative power, and controls needed to keep the plane stable had been damaged. An alarm sounded indicating the deterioration of flight systems.

Three minutes after that, more automatic messages reported the failure of systems to monitor air speed, altitude and direction. Control of the main flight computer and wing spoilers failed as well.

The last automatic message, at 11:14 p.m., signaled loss of cabin pressure and complete electrical failure — catastrophic events in a plane that was likely already plunging toward the ocean.

Patrick Smith, a U.S. airline pilot and aviation analyst, said the sequence of messages strongly indicated a loss of electrical power, possibly as the result of an extremely strong lightning bolt.

"What jumps out at me is the reported failure of both the primary and standby instruments," Smith said. "From that point the plane basically becomes unflyable."

"If they lost control and started spiraling down into a storm cell, the plane would begin disintegrating, the engines and wings would start coming off, the cabin would begin falling apart," he said.

Air France spokesman Nicolas Petteau referred questions about the messages to the French accident investigation agency, BEA, whose spokesman Martine Del Bono said the agency declined to comment. Jobim, the Brazilan defense minister, also declined to comment.

The accident investigation is being done by France, while Brazil is leading the recovery effort.

Reuters and The Associated Press contributed to this report.