Air France jet was flying too slowly: report

The paper said the manufacturer of the doomed plane, Airbus, was set to issue a recommendation advising companies using the A330 aircraft of optimal speeds during poor weather conditions.

Airbus declined to comment on the report and the French air accident investigation agency, which has to validate any such recommendations, known as an Aircraft Information Telex, was not immediately available for comment.

The Air France A330-200 was en route from Rio de Janeiro to Paris when it plunged into the Atlantic four hours into its flight. All 228 people on board died.

The plane sent no mayday signals before crashing, only a stream of automatic messages over a three minute period after it entered a zone of stormy weather, showing a rapid succession of electrical faults followed by a loss of cabin pressure.

It was not clear if slow air speed alone could trigger such a cataclysmic breakdown of aircraft systems, but any recommendations from Airbus about its A330s would fuel speculation over the causes of the crash.

"FLASH OF WHITE LIGHT"

Experts have questioned whether extreme turbulence or decompression during stormy weather might have caused the disaster -- the worst in Air France's 75-year history.

Spanish newspaper El Mundo said a transatlantic airline pilot reported seeing a bright flash of white light at the same time the Air France flight disappeared.

"Suddenly we saw in the distance a strong, intense flash of white light that took a downward, vertical trajectory and disappeared in six seconds," the pilot of an Air Comet flight from Lima to Madrid told his company, the newspaper reported.