JAKARTA, Nov 10 (AFP) - Indonesian investigators on Thursday (Nov 10) blamed mechanical problems and pilot complacency for a deadly plane crash last year that killed all 62 passengers and crew.

The Sriwijaya Air Boeing 737-500 nosedived 3,000m into waters off the capital Jakarta just minutes after takeoff on Jan 9, 2021.

In its final report, Indonesia's National Transportation Safety Committee (KNKT) pointed to several factors that contributed to the crash, starting with mechanical issues.

The twin-engine airliner's autothrottle system suffered a malfunction, which caused it to tilt off course, KNKT said in a press release.

The 26-year-old jet ended up sharply deviating from its intended flight path just before its deadly plunge.

Investigators said complacency may have resulted "in less monitoring" by the pilots, meaning the course change went unnoticed and they were not able to act quickly enough.

Their report further blamed a lack of regulation and official guidance for the lack of skill and knowledge in pilots to react to such situations.

Crews on previous flights had described the jet's throttle system as "unserviceable" and that it had been repaired several times before its fatal final flight, according to a preliminary report after the crash.

Indonesia is a vast archipelago with a poor air safety record despite relying heavily on air transport to connect its thousands of islands.

The country has suffered three major commercial plane crashes since 2014.

In October 2018, 189 people were killed when a Lion Air Boeing 737 MAX plunged into the sea.

That accident - and another in Ethiopia - led to the worldwide grounding of the 737 MAX model over a faulty anti-stall system.

And in 2014, an AirAsia A320 jet crashed into the Java Sea during bad weather, killing all 162 people on board.