Following the crash, investigators turned their attention to the plane's anti-stall system, which is responsible for changing the direction of the plane's nose when an "angle of attack" sensor reveals that the plane may be incapable of maintaining lift, the aerodynamic force produced by an airplane as it moves through the air.
The US Federal Aviation Administration informed airlines this month that incorrect inputs from the plane's anti-stall system's sensors could force the plane to adjust its nose downwards even when autopilot is turned off. According to KNKT, the anti-stall system was not properly detailed in Lion Air's flight manual.
On November 6, Boeing, the Chicago-based aircraft manufacturer, released a worldwide safety bulletin informing operators how to deal with erroneous angle sensor data.
According to reports, Lion Air co-founder Rusdi Kirana claims that Boeing is attempting to blame Lion Air for the crash by condemning its maintenance record and pilots' actions instead of taking responsibility for the anti-stall system design changes.
An Indonesian National Transportation Safety Committee report released last week showed that Lion Air JT610 recorded problems related to airspeed and altitude on four flights that took place three days prior to Flight 610's accident.
On October 28, a day before the flight, a maintenance engineer informed the pilot that the angle of attack sensor had been replaced and tested, although there are no records of the installation or calibration of the new sensor.
"He's very upset with Boeing," an airline financier who knows Kirana well told Reuters.
"I don't know if Rusdi is just using this to gain leverage on Boeing," said an aircraft lessor CEO, who spoke on the condition of anonymity, according to the Seattle Times.
Lion Air is currently awaiting the delivery of 190 Boeing jets worth $22 billion, in addition to the Boeing aircraft it currently owns.
"We are taking every measure to fully understand all aspects of this accident, and are working closely with the investigating team and all regulatory authorities involved. We are also supporting our valued customer through this very tough time," Boeing said in a recent statement obtained by media sources.
Boeing did not immediately respond to Sputnik's request for comments.
On November 21, Boeing was handed two wrongful death lawsuits filed by families of victims who lost their lives on Lion Air JT610. The lawsuits, which were filed in Cook County Circuit Court in Chicago, allege that Boeing is responsible for the deaths of the people on board, the Chicago Business Journal reported last week. One lawsuit was filed by 26-year-old Dayinta Dyah Anggana, whose 54-year-old mother died in the accident. The second lawsuit was filed by the family of two sisters who also died in the crash.
According to co-counsel for plaintiffs Steven Hart of the Chicago lawn firm Hart McLaughlin & Eldridge, "Boeing knew or should have known its aircraft and flight operations manual were unsafe and created a significant safety hazard, but the defendant failed to notify or warn anyone, which has caused immense pain and loss for surviving family members," the Business Journal reported last week.
The father of Rio Nanda Pratama, who died when the plane plunged into the sea, also filed a lawsuit against Boeing earlier this month in the US state of Illinois, the Jakarta Post reported.