The announcement came as fishermen found two more bodies from the crash in waters off Sulawesi island in central Indonesia, around 1,000 kilometres from where the plane crashed, a search and rescue official said.
Flight QZ8501 went down in stormy weather on December 28 in the Java Sea during what was supposed to be a short trip from the Indonesian city of Surabaya to Singapore. Only 72 bodies have so far been recovered.
They also revealed that the Airbus A320-200's less experienced French co-pilot, Remi Plesel, was flying the plane when it went down, rather than Captain Iriyanto, a former fighter pilot who had around 20,000 hours of flying time.
"The second-in-command was the pilot flying," chief investigator Mardjono Siswosuwarno told reporters in Jakarta, disclosing details from a preliminary report into the crash.
He said the captain sat on the left and acted as "the monitoring pilot".
"The captain has a choice whether to let the co-pilot continue flying and he does the trouble-shooting, or he takes control of the aircraft and allows the co-pilot to do the trouble-shooting," he told AFP.
He said it would not be clear whether the pilot made the right choice until more analysis of the plane's black boxes -- the flight data recorder and the cockpit voice recorder -- had been conducted and made public.
In 30 seconds, it rose from 32,000 feet to 37,400 feet, then dipped to 32,000 feet, before descending for around three minutes when the black boxes stopped, said investigator Ertata Lananggalih.
The transport commmitee also said the cumulonimbus clouds in the area reached heights of up to 44,000 feet at the time of the crash, although they declined to say whether the plane had flown directly into them.
