The voice recorder of a Lion Air plane that crashed last October was found, the Indonesian authorities said Monday, a discovery that could be essential to explain why the new aircraft fell from the sky shortly after takeoff .

The Boeing 737 Max disappeared from the radar about 13 minutes after taking off from Jakarta and crashed into the Java Sea moments after the pilots asked him to return to the capital and killed 189 people on board.

Haryo Satmiko, deputy head of the Indonesian National Committee for Transport Safety (NTSC), told AFP that the box had been found early Monday morning.

Investigators have already recovered the Boeing 737 Max flight data recorder, which provided information on the speed, altitude and direction of the aircraft before it dives to the sea on October 29th.

The preliminary accident report of the Indonesian Transportation Security Agency suggested that pilots flying 610 were having trouble controlling the aircraft's anti-stall system immediately before the accident.

The investigators also discovered that the Lion Air jet should have been immobilized due to a recurring technical problem prior to its fatal voyage, but did not identify the cause of the accident.

A final report of an accident will probably not be filed before the end of the year.

The bright orange voice recorder was discovered about 10 meters away from the aircraft's data logger, said Isswarto, commander of the Marine Air Search and Rescue Task Force.

– Boeing trial –

Despite their name, black boxes are usually bright orange with reflective stripes and all commercial aircraft are forced to have them on board.

They are built to survive at great depths and by very strong heat. They are equipped with a beacon that can emit a signal for a month.

The black box data help explain nearly 90% of all accidents, according to aviation experts.

The authorities canceled the difficult task of identifying the victims of the accident in November. Only 125 people were officially identified after tests on human remains filled with 200 body bags.

Following the demands of the families of the victims, Mr. Lion announced in December that he would allocate 38 billion rupees (2.6 million dollars) to rent a Dutch company to continue the search for his ship , the minivan Everest.

Nearly 30 relatives of the victims of the accident filed lawsuits against Boeing, alleging that the new model 737 MAX had been killed.

The Boeing single-aisle aircraft is one of the world's newest and most advanced commercial jet aircraft.

After the investigators had declared that the convicted aircraft was having problems with its speedometer and angle attack sensors, Boeing had to issue a special bulletin telling operators what to face to the same situation.

An AOA sensor provides data on the angle of airflow over the wings and tells pilots how much lift a plane has. The information may be essential to prevent an aircraft from landing.

The flight data recorder from the aircraft showed that pilots had tried repeatedly to prevent his nose from pointing down, probably after erroneous data from AoA sensors had been introduced into a system that automatically adjusts some of its movements.