PARIS — The captain of the Air France jet that crashed in the Atlantic two years ago was in the cockpit, though not at the controls, as the crew struggled to recover from a high-altitude stall, according to an initial chronology of the flight’s final moments published Friday by French investigators.

Based on roughly 1,300 pieces of newly recovered data, including the pilots’ final conversations, the report confirmed suspicions that a loss of consistent speed readings, probably a result of icing of the plane’s airspeed sensors, set off the chain of events that brought down Flight 447 en route from Rio de Janeiro to Paris.

But the investigators said it was far too early to say whether pilot error or technical malfunctions had caused the Airbus A330-200 to plummet 38,000 feet in three and a half minutes, slamming into the ocean surface at a vertical speed of nearly 11,000 feet per minute.

“We are still trying to interpret this information in order to have a better understanding of what happened,” said Jean-Paul Troadec, the director of the Bureau of Investigations and Analyses, or B.E.A., in France. “That work has just begun.” A more comprehensive report will be issued by the end of July, Mr. Troadec said.