The co-pilot was flying AirAsia Flight QZ8501, as the captain monitored the flight that crashed last month in the Java Sea with 162 people onboard.
The plane was in good condition and the crew were all certified, said Mardjono Siswosuwarno, the chief investigator for Indonesia’s National Transportation Safety Committee.
The AirAsia flight went down on December 28 as it flew from the Indonesian city of Surabaya toward Singapore.
The plane was veering left, when the pilot asked the control tower whether it could ascend to 38,000 feet, according to the national safety committee. Four minutes later, the plane was cleared to ascend to 34,000 feet.
Officials have said previously that the aircraft climbed rapidly before it fell into the water.
Investigators have submitted their preliminary report into the crash, officials said Tuesday, but it’s unclear when it will be released fully to the public.
Co-pilot Remi Emmanuel Plesel, 46, had less flying time than the captain with 2,275 hours with AirAsia Indonesia. He was also president of a French pilot association.
The captain of the ill-fated airliner, known only as Irianto — as many Indonesians go by one name — had more than 20,000 flying hours under his belt, 6,100 of which were with AirAsia on the Airbus 320. Irianto had been with AirAsia for six years and had worked for another airline in Indonesia for 13 years before that, and was an Indonesian Air Force pilot for a decade prior.
Indonesian aviation investigators are trying to establish why Flight QZ8501 went down in an area of heavy thunderstorms last month while other planes nearby completed their journeys safely.
Indonesian authorities have managed to recover 70 bodies from the sea, leaving 92 still unaccounted for.