SURABAYA - Investigators into the Indonesia AirAsia flight QZ8501 which crashed into the Java sea are focusing on the timing of the crew's request to climb to a higher altitude to avoid bad weather as a possible factor behind the tragedy, a source close to the probe said.
As Indonesian ships and aircraft recovered debris and bodies from the downed plane, the investigation into what happened on Sunday, when the aircraft carrying 162 people disappeared from radars, has only just begun.
Among the early lines of inquiry is whether the crew could have asked to ascend, or climbed on their own initiative in case of emergency, at an earlier stage, and what role storms in the area might have played.
"We know that the weather was very bad in this area, there was a storm," said the official, who declined to be named as he was not authorised to speak to the press.
"Why did he (the pilot) request to climb at that stage? Should he have climbed earlier? Other aircraft were flying at a higher altitude in that area. How did the two pilots react to the weather? We are asking those questions", he said.
Indonesia's National Transportation Safety Committee (NTSC) will lead the investigation into the crash of the Airbus A320, together with representatives from the United States, France and Britain, according to the source.
He said evidence such as radar data, weather reports, and the communication between the pilots and air traffic control has been gathered and is being studied.
The "black box" flight recorders have yet to be located, however, and the source cautioned that it was too early to draw firm conclusions as to what went wrong.
It was not immediately clear whether Indonesia's only pilots' union represented the captain, Iriyanto, although it works mainly with employees of national carrier Garuda Indonesia. Calls to the union late on Tuesday went unanswered.
Iriyanto, 53, spent more than 10 years as a pilot trainer before flying with airlines including Merpati Airlines, Adam Air and, for the last three years, AirAsia.
The former fighter pilot also flew with the Indonesian Air Force, according to friends and family.
AirAsia Group CEO Tony Fernandes said it was "too early to speculate" about the cause of the crash.
"I have full confidence in my ... crew. Our pilot was extremely experienced, (with) 20,000 hours (of flying time).
"He came from the air force, one of their best graduates. He came from Surabaya, so he knows the area very well", he told reporters in Surabaya.
Iriyanto's co-pilot on the crashed jet was Remi Plesel of France.