JAKARTA – A faulty design and certification process were crucial factors in the Lion Air Boeing 737 MAX 8 crash that killed 189 people last year in Indonesia, according to the final report into the accident released Friday by the country’s transportation authority.
The National Transportation Safety Committee’s report also said the pilots’ lack of knowledge of the flight-control system coupled with lax maintenance by Lion Air were factors that contributed to the tragedy.
Lion Air Flight JT610 – bound for Pangkal Pinang, Indonesia – plunged into the Java Sea shortly after takeoff from Jakarta on Oct. 29, 2018, killing everyone on board.
“The investigation considered that the design and certification of this feature was inadequate,” the report read, referring to the Maneuvering Characteristics Augmentation System, or MCAS.
The MCAS system is an anti-stall feature Boeing introduced on its new model that automatically activates when it detects the aircraft flying at a high pitch (angle of attack) and low speed to prevent it from stalling. The system pushes the plane’s nose down, causing it to gain speed and escape the aerodynamic stall.
However, MCAS was designed to operate on the basis of data from a single Angle of Attack (AoA) sensor – which malfunctioned and wrongly triggered the system to push the nose of the aircraft down. Pilots, who were unaware of the problem, reportedly attempted to counteract the system more than 30 times before losing control of the plane.
“Boeing assumed that MCAS’ dependence on a single sensor was sufficient to comply with certification requirements. We believe this system is vulnerable,” Nurcahyo Utomo, an investigator on the committee, said at a Friday press conference.
While the year-long investigation was ongoing, a second accident involving a Boeing 737 MAX 8 airplane occurred on March 10, 2019, in Ethiopia and killed 157 people.
The crash of Ethiopian Airlines Flight 302 under circumstances similar to those of the Lion Air crash caused the model to be grounded to this day and plunged Boeing into an unprecedented crisis.
The two crashes also have tarnished the once-sterling reputation of the United States’ Federal Aviation Administration (FAA), which certified both the MAX’s design and the MCAS feature.
Utomo said in the press conference that nine factors contributed to the accident and that if just one of them had not occurred “the accident may not have happened.”
Although the Indonesian committee avoided directly accusing any of the parties involved, six of the nine factors cited are related to the design and certification of the Boeing model.
The report concluded that the FAA based its decision on incorrect assumptions, recommended changes in the certification process and the 737 MAX flight manuals (which did not include information about MCAS) and called on Boeing to redesign that model.
Boeing said in a statement following the release of the Indonesian investigators’ report that the company has been making changes to the 737 MAX, most significantly redesigning how the plane’s Angle of Attack (AoA) sensors work with MCAS.
“Going forward, MCAS will compare information from both AoA sensors before activating, adding a new layer of protection,” the company said, adding that “MCAS will now only turn on if both AoA sensors agree, will only activate once in response to erroneous AoA, and will always be subject to a maximum limit that can be overridden with the control column.”
“These software changes will prevent the flight control conditions that occurred in this accident from ever happening again.”
Boeing, which said that since the Indonesia accident the 737 MAX and its software have been undergoing an unprecedented level of global regulatory oversight, testing and analysis, added that the company “is updating crew manuals and pilot training, designed to ensure every pilot has all of the information they need to fly the 737 MAX safely.”
The FAA, for its part, said in a statement that it welcomes the report’s recommendations and “will carefully consider these and all other recommendations as we continue our review of the proposed changes to the Boeing 737 MAX.”
“As we have previously stated, the aircraft will return to service only after the FAA determines it is safe,” the regulator added.
Investigators also said that the AoA sensor that provided data to MCAS on the fatal flight had been miscalibrated by a company in Florida and that there is no indication that Lion Air, a budget airline that had had a poor safety track record in the past and has expanded rapidly in recent years, tested that the sensor was working at the time of installation.
A Lion Air spokesman did not have any comment on the report when contacted by EFE.
Family members of the victims, who learned of the Indonesian investigators’ findings on Wednesday, mostly expressed disappointment over the lack of direct accusations.
Boeing faces dozens of lawsuits from relatives of the victims of both the Indonesia and Ethiopia crashes and also has set up a $50 million financial assistance fund to pay out separate compensation to those families.