Boeing is facing a lawsuit in an American court by the family of a victim of the crash of Lion Air Flight 610, which plunged into the Java Sea off Indonesia in October, killing all 189 people aboard.
Thomas Demetrio, the Chicago lawyer leading the suit, charges that Boeing failed to provide the Lion Air pilots with instructions on how to recover from a situation triggered by a failure in a sensor intended to warn of an impending aerodynamic stall.
“It was like Boeing first blindfolded and then tied the hands of the pilots,” the attorney said, announcing a filing on behalf of Sudibyo Onggo Wardoyo, a 40-year-old Indonesian passenger, his parents and his three siblings.
The suit renews focus on a change made to the controls of the latest model Boeing 737 MAX-8—a change that was not noted in the airplane’s flight instruction manual or explained to pilots during the training required as they transferred from older models of the 737.
The change, given the name Maneuvering Characteristics Augmentation System (MCAS), involved a few new lines of software. This was introduced after tests in a wind tunnel indicated a change in the handling characteristics of the MAX-8. The tests showed that under certain conditions, the jet could approach an aerodynamic stall in which the wing pitches up and suffers a sudden loss of lift.
During a flight that lasted only 11 minutes the Lion Air pilots fought against an action triggered by the MCAS that repeatedly forced down the nose of the jet—as it was intended to do when approaching a stall. Yet the Lion Air jet was never in danger of stalling.
The MCAS was responding to false data coming from a sensor designed to detect when the wing pitched up—a change in the angle of attack. By forcing down the nose, it eventually sent the jet into a terrifyingly violent dive into the sea.
The Chicago suit charges that Boeing placed in the jet “sensors that provided inaccurate data.” The airplane was only three months old; just over 200 of the MAX-8 models are in service with airlines, and this is the only reported incident involving a failure of the sensor. Investigators have been looking closely at the maintenance records of the jet. On the flight immediately preceding the fatal flight, pilots reported problems with the sensor. These were supposed to have been successfully dealt with during an overnight check.
It will be some while before investigators are ready to provide an explanation of what caused the crash, but a key target of the investigation will be why it was possible for a single-point failure—in this case of a sensor—could make it impossible for the pilots to recover control from a computer-driven system that they knew nothing about. All modern jets are designed with back-up systems to prevent a single-point failure from causing a crash.
Boeing’s defense of the MAX-8’s new system rests on its belief that the pilots should have recognized that they were facing a “runaway stabilizer” problem and that in both their training and the flight manual there were procedures for dealing with that.
Using those procedures, Boeing argues, the pilots could have overcome the way the computers were repeatedly forcing down the nose by resorting to a device in all 737 cockpits, the trim wheel, and by doing so regain control of the horizontal stabilizer. The trim wheel is, literally, a prominent wheel with a handle. When manually rotated by a pilot this wheel can override the commands from the computer.
The problem with this argument is that the pilots first have to detect what is forcing the nose down. In the case of Flight 610 the pilots were physically wrestling with a strong and stubborn force that kept moving the horizontal stabilizer without commands from them. Give that simultaneously multiple alarms would be sounding in the cockpit of impending loss of control, within only a few minutes of takeoff from Jakarta, the stress on the pilots would have been extreme.
Just precisely what hell the crew was going through and the exact sequence of their decisions is still unknown because investigators have still not recovered the cockpit voice recorder, second in importance only to the black box, or flight data recorder, that was recovered. Without the cockpit voice recorder the investigators cannot come to any definitive conclusion about whether the pilots carry any responsibility for the crash.
The crash also raises issues about the age of the 737’s basic design. A superficial look at the cockpit shows some state-of-the-art equipment, including large screens displaying key functions of the airplane and providing the pilots with a high degree of situational awareness—technology imported from Boeing’s most advanced jet, the 787 Dreamliner. But the basic controls of the 737 remain as designed in the 1960s: The control surfaces are activated by mechanical means, not by electronic commands as in all modern “fly-by-wire” systems.
The mechanical system is straightforward and usually very reliable. Those trim wheels, there since the 1960s, are essential to ensuring that pilots always have final authority in controlling the airplane, a principle that is basic to Boeing’s safety philosophy. But that philosophy did not work in this case because the pilots lost authority and never regained it.
Boeing has 30 days to answer the complaint brought by the firm of Corboy & Demetrio, a team of lawyers with decades of experience in dealing with air crashes, who were asked to take the case by Indonesian lawyers representing the Wardoyo family. Boeing can decide to file a motion to remove the case from a state to a federal court.
Boeing had no comment on the litigation.