French investigators say usable data has been extracted from the cockpit voice recorder of the Germanwings airliner which went down on Tuesday in the French Alps.
However, officials say it's still too early to say what might have caused the jet to go down.
Remi Jouty is in charge of the French Aviation Accident Investigation Agency.
"We just succeeded in getting an audio file which contains usable sounds and voices. We have not yet fully understood and worked on it to be able to say: 'Ok, this is starting at this precise point in flight, this is ending at this precise point in flight."
Officials do say the Airbus A320 hit the ground at high speed, suggesting there was no in-flight explosion.
Jouty is warning the investigation into the crash will take a while.
"This is an ongoing work, for which we hope to have first rough ideas in a matter of days, and having a full understanding of it, in conjunction with all the information coming in particular from other recorded parameters, will take weeks and even months."
The search for the airplane's flight-data recorder is still on-going.
The fight from Barcelona, Spain to Duesseldorf, Germany slammed into the mountains following an eight-minute descent on Tuesday, killing all 150 people on board.
Most of the victims are German and Spanish nationals, though victims from a dozen different countries were on the flight.
No Chinese nationals were among the victims.
There are now reports that bodies are being recovered and airlifted from the crash site.
The leaders of France, Germany and Spain have visited the site.
