Co-pilot at controls as AirAsia plane went down
In 30 seconds, it rose from 32,000 feet (9,800m) to 37,400 feet, then dipped to 32,000 feet, before descending for around three minutes when the black boxes stopped.
Investigators looking into the crash of AirAsia Flight QZ8501 said yesterday there were towering cumulonimbus clouds in the area reaching heights of up to 44,000 feet at the time of the crash. But they declined to say whether the plane had flown into them.
Cumulonimbus clouds, a type of cloud that is often dark and brings heavy rain or thunderstorms, can cause severe turbulence for aircraft.
Investigators also said that the co-pilot, Remi Plesel (above), was at the controls when the plane went down on Dec 28 in the Java Sea, AFP reported.
All 162 people on board the plane were killed.
"The second-in-command was the pilot flying," chief investigator Mardjono Siswosuwarno told reporters in Jakarta. He added that the captain was monitoring the flight and that the plane was in good condition.
Mr Gerry Soejatman, a Jakarta-based independent aviation analyst, said that while there was nothing unusual about the co-pilot being at the controls, the question was whether the captain took the right decision when the plane got into trouble.
He said: "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."
The investigators' announcement came as fishermen found two more bodies from the crash in waters off Sulawesi island in central Indonesia, around 1,000km from where the plane crashed, a search and rescue official said.
Investigators have been analysing data from the plane's black boxes - the flight data recorder and the cockpit voice recorder - and this week submitted a preliminary report to the International Civil Aviation Organisation.
The preliminary report was not released, but a final report is expected to be completed in seven to eight months and made public.