The flight data recorder was brought ashore, but the teams are still trying to locate the cockpit voice recorder, the BBC reported on Tuesday citing officials.

 

The authorities hope that data from the black boxes can give vital clues on the possible cause of the crash.

 

The 26-year-old aircraft passed an airworthiness inspection last month.

 

It was still functioning and intact before it crashed, preliminary results showed.

 

Flight SJ182 was en route from the capital Jakarta to the city of Pontianak on Borneo island.

 

Separately, Indonesian police have identified the first victim - Okky Bisma, a 29-year-old flight attendant.

 

Indonesia's transport ministry on Tuesday said the aircraft had been grounded during the pandemic, and passed an inspection on December 14.

 

It made its first flight five days later with no passengers before resuming commercial flights on December 22.

 

The National Transportation Safety Committee (KNKT) said that preliminary findings showed that the plane had reached the height of 10,900ft (3.3 km) at 2.36 p.m. local time on Saturday (07:36 GMT), then made a steep drop to 250ft at 14:40, before it stopped transmitting data.

 

KNKT head Soerjanto Tjahjono added that the plane's turbine disc had been found with a damaged fan blade - ruling out the theory that the plane had exploded mid-air.

 

"The damaged fan blade indicates that the machine was still functioning when it crashed. This (is) also in line with the belief that the plane's system was still functioning when it reached 250 ft," said Soerjanto in a written statement to reporters.

 

Search teams are continuing to comb the waters at the crash site, trying to retrieve the cockpit voice recorder.

 

Earlier on Tuesday, the KNKT said a device used to locate the black boxes had experienced "technical problems or equipment damage".

 

Several pieces of debris, body parts, wreckage and passengers' clothing have already been recovered.

 

Some 2,600 personnel were involved in the search operation on Monday, along with more than 50 ships and 13 aircraft.

 

Investigators are already analysing items which they believe to be a wheel and part of the plane's fuselage. An engine turbine has also been recovered.

 

Safety officials say this stage of the investigation could take up to a year.