Are Boeing’s planes safe? Following Lion Air crash, Boeing issued a safety bulletin explaining certain functions on 737 MAX planes - and how to deal with them in emergency. But instead of answering concerns, it fuelled them even more. And now the question of safety is being raised in a court as well.

A family of one of Lion Air JT610 crash victims – an Indonesian doctor Rio Nanda Pratama - is suing Boeing, claiming the flight control system on the MAX plane might have caused it. In an Illinois court (where the U.S. manufacturer is headquartered), the family is seeking unspecified damage.

The suspicion behind the suit lies on the hypothesis that the Boeing 737 MAX 8 crashed due to a Maneuvering Characteristics Augmentation System (MCAS) malfunction. The new system, installed on Boeing MAX planes, is activated when angle of attack (AOA) sensors indicate that the airframe is in a dangerous angle and attempts to correct it. But, if the AOA signal is erroneous, the MCAS can cause an airplane to stall. The investigation so far is hinting that it could be what happened to flight JT610.

On November 6, 2018, Boeing has issued a safety bulletin for MAX operators, directing them to follow existing flight crew procedures to address circumstances where there is erroneous input from an AOA sensor. Pilots can prevent a stall in an event of MCAS malfunction, but it takes several steps that require specific knowledge of this precise case. The procedure can be counter-intuitive, as the New York Times explains.  

Now, pilots unions, most notably those of the biggest 737 MAX operators in the United States, are debating on whether or not there has been sufficient information about the issue prior JT610. Following Boeing’s bulletin, representatives of both Southwest Airlines (LUV) and American Airlines (A1G) (AAL) pilot unions claim that MAX pilots were not informed about the new MCAS system, neither in training nor in 737 MAX manuals, Seattle Times reported on November 12, 2018.

“We do not like the fact that a new system was put on the aircraft and wasn’t disclosed to anyone or put in the manuals,” Jon Weaks, president of the Southwest Airlines Pilots Association, is quoted saying in the publication. What’s more, he noted, Boeing and the Federal Aviation Administration have now warned “that the system may not be performing as it should.”

The shocking claim would indicate that if pilots of the biggest United States legacy carriers were not aware of the new system, neither were Lion Air pilots. However, a chairman of United Airlines pilots union has expressed an opposite view, claiming pilots do not need to be aware of a new system in particular, as the 737 MAX manual indicates how to turn off flight control if it malfunctions for whatever reason.

The disagreement goes beyond pilots. Lion Air operational director, Zwingli Silalahi, also accused Boeing of withholding information related to the MCAS system. "We didn't receive any information from Boeing or from regulator about that additional training for our pilots," Zwingli told CNN. "We don't have that in the manual of the Boeing 737 MAX 8. That's why we don't have the special training for that specific situation".

Seattle Times quoted a former, anonymous, Boeing executive explaining that the MCAS system was installed on 737 MAX planes because they have bigger engines that change the plane’s aerodynamics. To pass safety requirements, additional protection was required to protect against possible aerodynamic stall.