A Boeing 737 belonging to Lion Air crashed on October 29 some minute after it took off from Jakarta. The investigators from Indonesia will submit their report on the crash that killed all the 189 people that were on board the aircraft.
This devastating crash is Indonesia’s second deadliest air disaster. The search is ongoing for the 737’s cockpit voice recorder, which is expected to be in the Java Sea. The investigation will focus on the anti-stall system of the Boeing 737 jet.
The systems of the jet had detected that it was stalling as a result of faulty equipment and the captain was warned via a stick shaker. The stick shaker vibrated the controls, which was revealed by Indonesia’s transport safety committee (KNKT) to the parliament last week.
The new 737 models had a further modification called MCAS or Maneuvering Characteristics Augmentation System that turned on and guided the nose of the jet down to prevent a stall.
In a flight that occurred the evening before, the anti-stall system had also activated. But the pilots on that flight managed to shut down the entire system.
The Indonesian Lion Air crash is the first crash that will involve the latest model in the 737 lineups, which is the 737 MAX that entered into service last year. But the flight manual for the jet did not include the Maneuvering Characteristics Augmentation System. The flight manual used by other American airlines did not include a description of MCAS too. The United States pilot unions revealed this.
But there is an established cockpit guideline for handling a runaway stabilizer. This runway procedure remains the same from the previous 737 models.
Dennis Muilenburg, the Chief Executive Officer of Boeing, said that Boeing provides all the information that is needed by pilots to fly their planes. He said this as the manual and training methods of the jet come under intense scrutiny.
After the initial findings made by the flight data recorder of the jet, Boeing shared a bulletin to airlines repeating established procedures and telling them to add information on MCAS to their flight manuals. This was followed by the FAA (Federal Aviation Authority) of the United States issuing a directive that made that compulsory.
A spokesperson for Boeing said that over 60 airline operators had discussed MCAS with Boeing since 2016. The pilot training and maintenance procedures of Lion Air was also under investigation after it was revealed that the crashed jet had issues with its airspeed indicator son its last four flights. But Lion Air said that they tackled all safety problems highlighted by previous flight incidents.
Investigations like this usually take about one year to complete as several factors cause air accidents of this nature. The investigators will spend a lot of time on the flight data recorder of the jet that contains about 69 hours of information from the last 19 flights of the plane.