Indonesian investigators say the Sriwijaya Air Boeing 737-500 plane crash last year which killed 62 people was due to a faulty throttle system and delayed pilot response.
Flight SJ-182 plunged into the Java Sea on 9 January 2021 minutes after take-off from Jakarta, killing all on board.
In their final report, investigators blamed several factors including a repeatedly faulty throttle system.
It was Indonesia's third major air accident in the space of six years.
Investigators said the plane - which was 26 years old - had an automated throttle system that suffered a malfunction shortly after take-off.
That had caused the jet to tilt sharply off-course before it nosedived 3,000m (10,000 ft) into the sea, the National Transportation Safety Committee (KNKT) said.
Previous flight crews had noted the throttle system was "unserviceable" and it had received regular repairs, the KNKT said, according to AFP news agency.
Investigators also noted that those in the cockpit had not reacted to the plane's deviation in time - perhaps due to complacency that resulted in "less monitoring" from the pilots.
The Sriwijaya Air crash underscored Indonesia's dismal air safety record, with three major commercial flight crashes in recent years.