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How the Boeing 737 Max 8 Anti-Stall System Can Lead to a Crash

In the wake of the March 10, 2019 Ethiopian Airlines Flight 302 crash, many aviation industry observers have postulated the existence of a link between the present incident and the Ethiopian Flight 302 disaster (that occurred back in October), as both incidents involved a Boeing 737 Max 8 and seem to have unfolded rather similarly after takeoff.  In both cases, the aircraft collided with the ground a short time after takeoff following a period of aggressive descent (with rapid fluctuations in pitch, presumably as the pilots fought to balance the nose of the aircraft and prevent a ground collision).

Though it’s not entirely clear what caused the Ethiopian Airlines Flight 302 crash, it’s possible that the new Maneuvering Characteristics Augmentation System (MCAS), implemented on the Boeing 737 Max 8, contributed to the accident.

Understanding the MCAS-AOA Interaction

The MCAS is an anti-stall system that was added to the Boeing 737 Max 8 (and Max 9).  The system processes airspeed data and data from the angle-of-attack (AOA) sensors on the plane to determine whether the plane is flying at too severe an angle (and is therefore at-risk of stalling).  When the MCAS interacts with AOA data that indicates a risk of stalling, it automatically pitches the nose down.

Now, the MCAS system is not, in and of itself, a problem, except when it interacts with AOA sensors that are providing erroneous data. If an AOA sensor is faulty, then it could cause the MCAS to activate when the plane is not actually stalling, thus pushing the aircraft into an aggressive dive.

Despite having implemented such an advanced and powerful new system, Boeing did not provide training or any notice in the training manuals (for the 737 Max 8) regarding the MCAS and procedures for shutting it off.  As such, pilots — who rely on memorized procedures, particularly in dangerous situations — were not equipped to correct the problem when it cropped up during the flight.

Though Boeing supposedly updated the training manual and notified airlines as to the MCAS implementation following the Ethiopian Flight 302 disaster in October 2018, it appears that their efforts may have been incomplete or otherwise inadequate, as the US Federal Aviation Administration is requesting that Boeing update the training manuals and provide a software update to enhance the MCAS-AOA interaction.

Evidence Linking Two Major Crashes and Changes Planned by Boeing

On March 13, 2019, the US joined more than 45 other countries in grounding the Boeing 737 Max 8 (and Max 9) until the aircraft could be deemed airworthy again, on the basis of new evidence that was collected from the Ethiopian Airlines Flight 302 crash site, that could provide a link between Ethiopian Flight 302 — which crashed due to activation of the MCAS and erroneous sensor data — and Ethiopian Airlines Flight 302.

The Federal Aviation Administration (FAA), who made the grounding decision, did not go into further detail about the nature of this newly-available evidence and what it might indicate with regard to the cause of the Ethiopian Airlines disaster. They did, however, note that their decision was driven by this new evidence, in conjunction with refined satellite data that became available to them the same morning.

The FAA also ordered that Boeing implement changes by April if the aircraft were to be considered airworthy again. The changes include an update to training requirements and flight crew manuals specifically relating to the new MCAS.  Boeing is also being required to update the MCAS and angle-of-attack sensors so that their activation is more finely-tuned and enhanced.

Contact Our Experienced Aviation Lawyers for Assistance

At Podhurst Orseck, we have extensive experience handling aviation disaster claims on behalf of victims and their surviving family members. Steven C. Marks and our other attorneys have served as lead trial counsel, co-lead counsel, and more in a variety of high-profile commercial airline crash litigation, including, but not limited to, the following: Malaysian Airlines Flight MH370, SilkAir Flight MI185, Metrojet Flight 9268, and more.

When litigating a claim against an airline, there are specific procedures, expectations, and strategies that must be taken into account. The depth of our litigation experience has given us key insight into what is necessary in order to successfully navigate the complexities of such a dispute.

Contact us for immediate guidance on how to proceed.