The search for downed Lion Air Flight JT610 has suffered an unexpected setback after the quest to recover the body of the aeroplane came up empty-handed.

Experts believed they had finally discovered the fuselage, or main body of the aircraft, but instead, the 22m-long object detected on the sea floor turned out to be aircraft debris and passenger belongings.

Muhammad Syaugi, head of Indonesia's Search and Rescue Agency, told reporters that the search effort was battling strong currents but they remained confident the aircraft hull would be found.

The discovery of the Boeing 737-MAX jet's main body would have been a breakthrough in solving the mystery as investigators were hoping it would lead them to flight data recorders, referred to colloquially as "black boxes".

Advertisement

Pings, believed to be from he flight recorder due to their regular intervals, had been detected earlier but the strength of the currents has prevented the black box from being recovered.

Data from flight-tracking sites show the plane had erratic speed and altitude in the early minutes of a previous flight on Sunday and on its fatal flight on Monday.

Safety experts caution, however, that the data must be checked for accuracy against the plane's black boxes.

The two-month-old Boeing 737 MAX 8 plunged into the Java Sea just 13 minutes after takeoff from Jakarta, killing all 189 people on board and baffling aviation experts.

Lion Air has said that maintenance was carried out on the aircraft after the problematic Sunday flight and the issue, which it didn't specify, was fixed.

Two passengers on the Sunday Bali-bound flight interviewed on Indonesian TV recalled unsettling details such as a strange engine sound, a smell of burnt cables, and panicked passengers crying out for God to save them as the plane rapidly lost altitude.

Later in the flight, a man who was either the captain or first officer walked through the plane and returned to the cockpit with what looked like a large manual.

Boeing officials were expected to meet with Lion Air, after Indonesia ordered an inspection of the US plane maker's 737-MAX jets.

Rescuers scan the horizon during a search operation for the victims of Lion Air plane crash in the waters of Tanjung Karawang, Indonesia.
Rescuers scan the horizon during a search operation for the victims of Lion Air plane crash in the waters of Tanjung Karawang, Indonesia.

The downed plane, which went into service just a few months ago, was en route to Pangkal Pinang city when everything went south.

Indonesia's Transport Minister fired the technical director of Lion Air as well as staff who approved the flight of the jet.

Transport Minister Budi Karya Sumadi says the airline will be subjected to a ministry inspection and operations of all low cost airlines in Indonesia will be reviewed.

"Today we will remove Lion's technical director from his duties to be replaced by someone else, as well as technical staff" who cleared the flight to depart, the minister told reporters.

Aviation experts say it is too early to determine what caused the accident but Lion's admission that the plane had an unspecified technical issue on a previous flight — as well as the plane's abrupt nosedive just 13 minutes after takeoff — have raised questions about whether it had any faults specific to the newly released model, including a speed-and-altitude system malfunction.

"The bigger picture here is that you've got a lot of American carriers flying the same aircraft," Stephen Wright, aviation expert at the University of Leeds, told AFP.

"Is there (a problem) that could affect other aircraft?"