Warning alarms in an AirAsia plane were "screaming" as pilots desperately tried to stabilise the jet before it plunged into the Java Sea last month, a crash investigator says.
The noise of several alarms - including one that indicated the plane was stalling - can be heard in recordings from the black box in AirAsia flight QZ8501's cockpit, the investigator from Indonesia's National Transportation Safety Committee (NTSC) said.
The official, who requested anonymity, said the warnings were going off for some time and the pilots' voices were drowned out by the sound of the alarms.
The revelation came a day after Indonesian transport minister Ignasius Jonan said that the Airbus A320-200 had climbed abnormally fast before stalling and plunging into the sea, as it flew on 28 December in stormy weather from Indonesia to Singapore with 162 people on board.
Analysts said the AirAsia jet's rapid ascent had echoes of the crash of an Air France jet into the Atlantic in 2009, with the loss of 228 lives. The Airbus A330's speed sensors were found to have malfunctioned, and the plane climbed too steeply, causing it to stall.
The investigation into Air France flight 447 found that both technical and human error were to blame.
However, a senior pilot and an aviation expert have criticised the country's transport minister for suggesting the plane was climbing too fast.
Captain Sardjono Jhony was the chief executive of Indonesia's Merpati Airlines and a pilot for Etihad and Qatar Airways. He said it was possible for flight QZ8501 to climb to 6000 feet, because of the updraft.
Independent Indonesian aviation analyst, Gerry Soejatman agreed, saying it was unusual but not impossible.
The aviation experts warned the cause of the crash may remain a mystery for up to a year and urged people to wait for the result before speculating.
The two black boxes - the cockpit voice recorder and the flight data recorder - were recovered last week after a lengthy search, and investigators are examining them.
They are focusing on the possibility of human or aircraft error, after ruling out terrorism following an analysis of the cockpit voice recorder.
National Transportation Safety Committee head Tatang Kurniadi said the preliminary report into the crash would be completed next week, a month after the accident. He said the full report would not be released publicly but the media would be told some of its contents.