A pilot flying the same Lion Air plane that later crashed, made an alert call minutes after takeoff from Bali due to technical problems, but they were overcome and he pushed on to Jakarta.
Hours later the same plane plummeted into the sea near Jakarta, killing all 189 people on board.
Herson, chief of the airport authority for the Bali-Nusa Tenggara area, told Reuters that after the call on Sunday the pilot updated the control tower to say that the plane was flying normally and he would not return to the airport as requested.
"The captain himself was confident enough to fly to Jakarta from Denpasar," said Herson, who goes by one name, speaking by phone from Bali.
Indonesian rescue teams operate during the recovery mission for the crashed Lion Air flight JT-610 plane. Source: AAP
The pilot of another plane that was approaching Bali just after the Lion Air jet took off said he was ordered to circle above the airport and listened in to a radio conversation between the Lion Air pilot and air traffic controllers.
"Because of the Pan-Pan call, we were told to hold off, circling the airport in the air," said the pilot, who declined to be named.
"The Lion plane requested to return back to Bali five minutes after take-off, but then the pilot said the problem had been resolved and he was going to go ahead to Jakarta."
Pilots use Pan-Pan calls to flag urgent situations. They are a step down from Mayday, which signals severe distress.
Families of passengers on board the crashed Lion Air flight show pictures of their loved ones. Source: Getty images
A Lion Air spokesman declined to comment when asked about the distress call on the earlier flight, citing the ongoing crash investigation.
Amid media speculation over the airworthiness of the aircraft, the transport minister suspended Lion Air's technical director and three other officers on Wednesday to facilitate the crash investigation.
During its earlier flight from Bali on Sunday the aircraft flew erratically and its airspeed readings were unreliable, according to an accident investigator and a flight tracking website.
According to data from FlightRadar24, the jet displayed unusual variations in altitude and airspeed in the first several minutes of flight - including an 267-metre drop over 27 seconds when it would normally be ascending - before stabilising and flying on to Jakarta.
Investigators examine data recorder
Divers on Thursday retrieved a flight data recorder from the plane that lay shattered on the muddy sea floor off the coast of Jakarta.
The NTSC said it would examine the device to get a clearer picture of what happened on the flight from Bali on Sunday in addition to the flight that crashed on Monday.
Searchers pack away the black box, which was found about 400 meters from the aircraft's last recorded position. Source: AAP
The investigation into the first ever crash of the Boeing Co 737 MAX, introduced into commercial service last year, will also be scrutinised by the global aviation industry.
"Tonight we will move as quickly as possible to download what is in this black box," deputy chief of Indonesia's transportation safety committee (KNKT) Haryo Satmiko told a news conference on Thursday.
The extent of damage to the device showed the "extraordinary impact" of the crash, he said.
Despite initial reports, authorities did not know for certain whether the "crash survivable memory unit" was from the flight data recorder or cockpit voice recorder, as portions of it were missing, Satmiko said.
Searchers have yet to detect a location signal from the second of the two black boxes, housed at opposite ends of the aircraft. Although the sea floor is only about 30 metres down, strong currents and energy pipelines in the area have hampered search efforts.
The plane, which had only been in service since August, went silent 13 minutes after taking off on Monday from Jakarta, heading for the tin-mining town of Pangkal Pinang.
The pilot had already received permission to return to base.
A navy diver on board a search vessel told the broadcaster Metro TV that his team found the orange cylinder containing the recorder among debris on the muddy sea floor.
Families of the victims of Lion Air flight JT610, visit an operations centre to look for personal items of their relatives. Source: AAP
Under normal conditions, the data should only take two hours to download, said Satmiko, although analysing it could take several weeks.
The results from a preliminary investigation will be made public after 30 days, another KNKT official said.
"What is important for us is to get more information about the victims because having their remains back is important for us so we can bury them properly," said Ade Inyo, whose brother-in-law was on the flight.
Only one of the flight's passengers has been identified from the partial remains retrieved so far.
A rescuer inspects personal belongings of passengers during the search operation for the victims of the Lion Air jet. Source: AAP
The investigation will be carried out with help from Boeing, General Electric and the US Federal Aviation Administration, officials have said.
It will also focus on four Lion Air staff, including its technical director, who the transport ministry said it has suspended on Wednesday, amid speculation that the aircraft had not been airworthy.
Lion Air said the aircraft that crashed had been airworthy and the pilot and co-pilot had 11,000 hours of flying time between them.
But according to the transport safety committee, the plane had technical problems on its previous flight on Sunday, from the resort island of Bali, including an issue concerning "unreliable airspeed".
