Ethiopian jet's cockpit recorder data successfully downloaded: French Aviation Authority

Ethiopian Airlines flight 302, which crashed killing 157 people, had an unusually high speed after take-off before the plane reported problems and asked permission to climb quickly, said a source who has listened to the air traffic control recording.

The French agency said in a tweet it had not listened to the audio files and that the data had been transferred to Ethiopian investigators.

"Data from the CVR has been successfully downloaded by @BEA_Aero and transferred to the Ethiopian investigation team / communication on their behalf / @BEA_Aero did not listen to the audio files," BEA wrote on Twitter.

It added that work on the flight data recorder would resume on Sunday.

The Ethiopian flight was set to follow the Standard Instrument Departure (SID) from the airport and followed standard procedure with a first contact just after departure, the source said. Everything appeared normal.

A voice from the cockpit of the Boeing 737 MAX asked to climb to 14,000 feet above sea level - 6,400 feet above the airport - but vanished from radar at 10,800 feet after starting a right turn home due to what the pilot described as a flight control problem, the source said on condition of anonymity because the recording is part of an ongoing investigation.

Shortly before the maneuver, the air traffic controller had been in communication with other aircraft when the voice from Ethiopian Airlines flight 302 interrupted, saying “break, break” - signaling that other non-urgent communications should cease. The pilot sounded very scared, the source said.

“He requested permission to return. Air traffic control granted him permission to turn on the right because to the left is the city,” he said. “Maybe one minute passed before the blinking dot on the radar disappeared.”

After starting the turn, the plane disappeared from radar at an altitude of 10,800 feet above sea level, the highest it reached during the six-minute flight. Addis Ababa’s runway is at a high elevation of around 7,600 feet, suggesting the doomed jet made it about 3,000 feet into the sky.

Flight tracking website FlightRadar24 had data covering the first half of the flight but it dropped out at 8,600 feet.

Other satellite data tracking the plane has not been made available publicly. In the Lion Air crash, investigators are examining the behavior of a new anti-stall system installed on the 737 MAX that led to the plane gaining and losing altitude as the pilots fought for control against the automated system.

Boeing is expected to finalize a software fix for that system within a week to 10 days, sources familiar with the matter said earlier on Saturday.