The doomed Lion Air jet's last four flights all had an airspeed indicator problem, according to black-box data, says the head of Indonesia's National Transportation Safety Committee, Soerjanto Tjahjono.
Tjahjono and investigator Nurcahyo Utomo told a news conference on Monday that the problem was similar on each of the four flights, including the fatal flight on October 29 that killed all 189 people on board.
The stunning revelation on Monday comes after angry relatives confronted the airline's co-founder at a meeting organised by Indonesian officials.
At the meeting, Tjahjono said information downloaded from the flight data recorder is consistent with reports the plane's speed and altitude were erratic. Searchers are still trying to locate the cockpit voice recorder.
Lion Air flight 610 crashed into the Java Sea on October 29 killing all 189 on-board. The Boeing 737 crashed shortly after takeoff.
At least 105 body bags containing parts of passengers have been handed to the national police hospital in Jakarta for identification.
Investigators and agencies from around the world continue the week-long search for the main wreckage and cockpit voice recorder which might solve the mystery.
The new details revealing an air speed indicator problem — gleaned from a recovered flight data recorder — come after the government said it was launching a "special audit" of the budget carrier's operations.
Lion — long dogged by safety problems — has said the Boeing 737-Max 8 suffered a technical issue on the flight just prior to its deadly crash Monday and that it was fixed.
But the National Transportation Safety Committee (NTSC) said on Monday that the black box data showed the plane had an air speed indicator issue on at least two other earlier flights.
"There were four flights in all that suffered a problem with the airspeed indicator," NTSC head Soerjanto Tjahjono told reporters.
"When there was a problem, the pilot would write it down and the mechanic would do (a repair) … Then the plane would be declared airworthy."
The agency said it would probe what caused the indicator problem and whether proper repairs were done — including replacing the faulty component, he added.
It did not give more details and did not speculate on how the indicator problem may have played a role in the crash, as it continues to mine the flight recorder — seen as key to answering why a nearly brand new plane fell out of the sky.
"Special audit" as Lion Air admits to "expensive lesson"
Lion's earlier admission that the jet had a technical issue — and the captain's request to turn back to the airport minutes before the crash — have raised questions about whether it had faults specific to one of the world's newest and most advanced commercial passenger planes.
Flight JT610 sped up as it suddenly lost altitude and then vanished from radar 12 minutes after takeoff, with witnesses saying the single-aisle jet plunged into the water.
Lion has been a regular target of complaints about poor service, unreliable scheduling and safety issues, including a fatal 2004 crash.
"We will … conduct a special audit of the crews' qualifications and staff communication," transportation minister Budi Karya Sumadi told reporters Monday as he announced the probe into Lion's operations.
"This is a preventive measure …(The accident) is a very expensive lesson for us."
Civil Aviation authorities in the United States and Europe were also being consulted for their help in the probe, he added.
Meanwhile, authorities have extended their search as they collect more body parts and shattered debris from the spot where the plane crashed during a routine one-hour flight from Jakarta to Pangkal Pinang.
Scores of body bags filled with remains have been collected and sent for DNA testing, but so far just 14 people have been identified.
Search and rescue agency head Muhammad Syaugi tearfully apologised Monday as relatives' clamour for answers grew louder, with accusations that the pace of recovery is lagging.
"We are not perfect human beings," he said, sobbing. "We have flaws, but we [are] doing the best we can."
The Lion Air investigation comes after Indonesia's government ordered an inspection of all Boeing 737 Max 8 planes in the country.
All were found to be airworthy although two required repairs for "minor" problems.
The accident has resurrected concerns about Indonesia's poor air safety record, which until recently saw its carriers facing years-long bans from entering European Union and US airspace.
Divers are still hunting for the plane's cockpit voice recorder.
- With wires