"However, the New York Times quoted an unnamed investigator as saying that one of the pilots - it is not clear if it is the captain or the first officer - left the cockpit and had been unable to get back in.

"The guy outside is knocking lightly on the door, and there is no answer," the investigator said, describing audio from the recorder.

"And then he hits the door stronger, and no answer. There is never an answer. You can hear he is trying to smash the door down.""

資料來源:http://www.bbc.com/news/world-europe-32062278