Lion Air was unfit for flight
In a statement, Indonesia's transport safety committee (KNKT) recommended that Lion Air improve its safety culture following the crash of the almost-new Boeing 737 MAX 8.
The MAX 8, the latest version of the 737, includes an automated system that pushes the nose down if a sensor detects it is pointed so high the plane is at risk of an aerodynamic stall.
Investigators are focusing on whether faulty information from sensors led the plane's system to force the nose down.
Speaking from Jakarta, Al Jazeera's Step Vaessen said the plane had been causing problems for pilots for four days previously.
"There were a lot of technical issues with the same plane," she said, adding that the main problem was that the so-called 'angle of attack' indicator did not appear to be working properly.
"The pilots (on the earlier flights) turned this off and flew manually. But on the fatal flight, the pilots made a different decision. They didn't fly manually."
Given the difficulties, Lion Air should not have been flying the plane, Nurcahyo Utomo, aviation head of the National Transport Safety Committee, told reporters.
"During the flight from Denpasar to Jakarta (the last flight before the crash), the plane was experiencing a technical problem, but the pilot decided to continue the flight," he said.
"In our opinion, the plane was no longer airworthy and it should not have continued flying." ■