The passenger aircraft involved in the deadly Indonesian Sriwijaya Air crash on January 9 had throttle "anomalies," investigators said on Wednesday.

"The left [engine throttle] was moving backward too far while the right one was not moving at all — it was stuck," National Transportation Safety Committee lead investigator Nurcahyo Utomo said at a press conference.

The throttle leavers are used by the pilot of a plane to control the amount of thrust of an aircraft's engines — similar to an accelerator or gas pedal in a car.

The finding was announced as part of a preliminary report into why the Boeing 737-500 crashed minutes after takeoff into the Java Sea. All 62 crew and passengers on board were killed.

Probe into crash continues

Utomo stopped short of saying the throttle problems caused the crash: "We are still investigating what went wrong because there are 13 components connected to the throttle."

The aircraft's cockpit voice recorder, which is still missing, could provide more answers on what happened during the flight, Utomo added.

Pilots of previous flights had reported problems with the automatic throttle system on the 26-year-old jet, added Utomo.

The plane was out of service for almost nine months last year because of flight cutbacks caused by the coronavirus pandemic.

Regulators and the airline said it underwent inspections before resuming commercial flights in December.

 A full report on the crash is expected early next year.

kmm/rs (dpa, AP,AFP)