Boeing’s underlying 737 design enjoys a respected position in the aviation industry. The short-to-medium range, twin-jet aircraft first entered commercial service in 1968, and since then, it has become the best-selling commercial jetliner in history, with over 10,000 aircraft delivered by March 2018.  Over its many decades of service, the 737 is widely considered to be the most reliable in the industry.

In 2011, Boeing began to experiment with a new design for the 737 to better compete with some of the newer offerings by Airbus.  The 737 Max 8 is the first variant developed in the 737 Max series, the fourth (and the company’s latest) generation of the popular, narrow-body aircraft.  The Max series was intended to improve operational efficiency by reducing fuel consumption, extend the service range, enhancing aerodynamics, strengthening the structure of the aircraft, and providing additional clarity to pilots via an upgraded cockpit display system.

When the 737 Max 8 was launched in 2016, these improvements made the aircraft particularly attractive to low-cost carriers.  As of today, Boeing has already delivered 350 units to clients around the world and is processing orders for 4,661 more.

Boeing Made Significant Changes

Structural

With the 737 Max Series, Boeing made a large number of structural changes, including a split wingtip, heavier, more forward-placed engines, thicker landing gear, redesigned power units, and various other improvements.

MCAS Implementation

The most controversial change implemented on the 737 Max 8 was the introduction of a Maneuvering Characteristics Augmentation System (MCAS), an anti-stall system that is intended to automatically lower the nose of the aircraft down when sensor data reveals that the plane is operating at a dangerous angle-of-attack.

There are two main, interrelated problems with the MCAS implementation.  First, when the angle-of-attack sensors are providing erroneous data to the MCAS, the plane’s nose may be trimmed down in an anti-stall procedure (despite the fact that the plane is not actually stalling).  It is not yet known whether this issue contributed to the Flight 302 crash, but the investigation into Ethiopian Flight 302 did, in fact, suffer from this issue.

Second, Boeing did not provide adequate training/notification to airlines and pilots regarding the new MCAS implementation.  It was not until the Ethiopian Flight 302 disaster that Boeing followed up by issuing an emergency airworthiness directive so that pilots would be equipped to respond to erroneous MCAS-sensor interaction.

Post-Accident Response

Since the Ethiopian Airlines Flight 302 disaster, more than 45 countries have grounded all Boeing 737 Max 8 flights and have suspended further operation until the aircraft is deemed airworthy.  On March 14, 2019, Boeing took an active step and grounded all 737 Max series aircraft worldwide until further notice, thus eliminating the need for governments to evaluate airworthiness on a case-by-case basis.

Boeing’s response following the two major 737 Max 8 disasters — Ethiopian Flight 302 on October 28, 2018 and Ethiopian Airlines Flight 302 on March 10, 2019 — has been rather piecemeal and insubstantial.  After the Ethiopian Flight 302 crash, Boeing issued an emergency airworthiness directive, advising pilots in-training (and airlines operating the 737 Max 8) on how to appropriately respond to activation of the MCAS when the system is being guided by erroneous sensor readings.

Despite the fact that Boeing has issued the directive, it is not yet clear what extent the company went to ensure that airlines (and their pilots) had the tools and information necessary to adequately re-train pilots on how to respond to the dangers of MCAS-AOA erroneous sensor interaction.  If the Flight 302 crash was caused by improper activation of the MCAS in response to erroneous sensor data and Boeing did provide Ethiopian Airlines sufficient guidance on how to address such situations, then Ethiopian Airlines could potentially be held liable for failing to provide the necessary training to update 737 Max 8 pilots on what to do under the circumstances.