Ethiopian Airlines Flight 302 – March 10, 2019

On March 10, 2019, Ethiopian Airlines Flight 302, a Boeing 737 MAX 8, crashed six minutes after takeoff from Addis Ababa, Ethiopia, en route to Nairobi, Kenya. All 157 passengers and crew perished in the crash. This tragic incident occurred only a few months after the Lion Air Flight 610 crash, involving the same Boeing 737 MAX model and the same problematic Maneuvering Characteristics Augmentation System (MCAS). Both crashes had similar causes, centered around faulty sensor readings that led the automated MCAS to repeatedly push the aircraft’s nose down, despite the pilots’ efforts to regain control.

Sequence of Events Leading to the Crash

Flight ET302 departed from Addis Ababa’s Bole International Airport at 08:38 local time, climbing steadily before encountering trouble. Within minutes of takeoff, the aircraft’s angle-of-attack sensors transmitted erroneous data to the flight control systems, triggering the MCAS. As a result, the MCAS erroneously forced the plane into a nose-down attitude to prevent a perceived stall, despite the aircraft being at normal flight conditions.

The pilots, realizing the MCAS was pushing the nose down, attempted to counteract the system by pulling back on the control column and using trim controls to stabilize the aircraft. However, MCAS re-engaged repeatedly, overriding their inputs. The struggle between the pilots’ manual corrections and the MCAS continued for several minutes before the plane entered an uncontrollable dive and crashed into the ground at high speed, near the town of Bishoftu, Ethiopia. The wreckage was scattered over a large area, leaving no survivors.

Investigation and Findings

The Ethiopian Civil Aviation Authority, along with international investigators including the U.S. National Transportation Safety Board (NTSB) and the French BEA, conducted a thorough investigation into the crash. The investigation revealed that faulty data from a single angle-of-attack (AOA) sensor caused the MCAS to activate erroneously. The MCAS was designed to assist pilots in preventing stalls by automatically adjusting the aircraft’s pitch. However, the system relied heavily on data from just one sensor, making it vulnerable to failure if that sensor malfunctioned.

The report highlighted that the MCAS continued to push the plane’s nose down repeatedly, and despite the pilots’ attempts to disable the system, it overpowered their efforts to recover the aircraft. Additionally, investigators noted that the training provided to pilots regarding the MCAS system was insufficient, as Boeing had not fully disclosed the presence of the MCAS or its behavior under certain conditions to airlines or pilots prior to the Lion Air crash.

Boeing 737 MAX Grounding and Global Fallout

The crash of Flight ET302 led to the worldwide grounding of the Boeing 737 MAX fleet. Regulatory bodies, including the Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA), ordered airlines to suspend all flights of the 737 MAX until further notice. This grounding lasted for 20 months, during which Boeing faced intense scrutiny over its design and certification process for the MCAS system.

Boeing subsequently made extensive modifications to the MCAS, including ensuring that the system relied on data from multiple sensors rather than just one, and revising pilot training programs to better prepare crews for MCAS-related scenarios. Boeing also faced legal challenges from the families of the victims, airlines, and regulators. The manufacturer settled with the U.S. Department of Justice in 2021, paying $2.5 billion to avoid criminal charges related to fraud during the certification of the 737 MAX. However, the settlement was met with criticism, particularly from the victims’ families, who sought greater accountability.

The Role of MCAS and Pilot Training

The MCAS system was a key feature introduced on the Boeing 737 MAX to compensate for the aircraft’s larger, more fuel-efficient engines, which altered the aircraft’s aerodynamic behavior. Under certain conditions, the MAX had a higher tendency to pitch up, prompting the development of the MCAS to automatically correct the angle of attack. However, the reliance on a single AOA sensor for such critical corrections proved to be a fatal design flaw.

In both the Lion Air and Ethiopian Airlines crashes, the pilots were unable to regain control of the aircraft due to the repeated activation of the MCAS, which overrode their inputs. The investigation highlighted that Boeing had not fully explained the system’s functionality to airlines and pilots, and as a result, many pilots were unaware of how to properly respond to MCAS malfunctions. This lack of awareness and training compounded the dangers posed by the flawed system.

Legal and Regulatory Consequences

Boeing’s legal troubles extended beyond the grounding of the 737 MAX. In 2021, the company agreed to a $2.5 billion settlement with the U.S. Department of Justice to avoid criminal prosecution for fraud. The settlement included $500 million in compensation for the families of the victims, $1.77 billion in compensation to airlines that had to ground their fleets, and a $243.6 million fine. However, this settlement was controversial, with the victims’ families arguing that they should have been consulted and involved in the settlement process.

In January 2023, Boeing pleaded not guilty to conspiracy to commit fraud charges in a Texas court after a judge ruled that the settlement had inadequately addressed the concerns of the victims’ families. The legal battle continues as the families seek greater accountability from Boeing and the FAA, which they argue should have exercised more oversight during the aircraft’s certification process.

Lessons Learned and Aviation Reforms

The Ethiopian Airlines Flight 302 disaster, alongside the Lion Air Flight 610 crash, resulted in significant changes to global aviation safety regulations. Following the two crashes, the FAA and other aviation regulatory bodies implemented stricter oversight procedures for the certification of new aircraft systems, ensuring that critical safety features like the MCAS are rigorously tested and fully disclosed to airlines and pilots.

The grounding of the 737 MAX prompted Boeing to redesign the MCAS system, incorporating multiple AOA sensors and improving redundancy. Additionally, new training programs were mandated for all 737 MAX operators, ensuring that pilots are fully trained on how to respond to MCAS malfunctions.

The crashes also led to a re-evaluation of the relationship between aircraft manufacturers and regulators. Critics pointed out that Boeing’s close relationship with the FAA may have contributed to lapses in oversight during the certification of the 737 MAX. In response, reforms were introduced to improve transparency and independence in the aircraft certification process, reducing the potential for conflicts of interest between manufacturers and regulatory bodies.

Conclusion

The crash of Ethiopian Airlines Flight 302 was a tragic event that underscored the dangers of relying on flawed systems like the MCAS without adequate safeguards and pilot training. The loss of 157 lives, just months after the Lion Air crash, brought about significant changes in the aviation industry, leading to a worldwide reassessment of safety procedures and certification processes. The grounding of the Boeing 737 MAX and the subsequent redesign of the MCAS system were necessary steps to prevent future tragedies, but the legal and ethical questions surrounding Boeing’s responsibility remain unresolved for many.

The aviation industry continues to learn from these incidents, focusing on enhancing pilot training, improving aircraft design, and ensuring that regulatory oversight is robust and independent. While the return of the 737 MAX to service marks a new chapter in aviation safety, the legacy of the two crashes serves as a somber reminder of the importance of vigilance, transparency, and accountability in the pursuit of safer skies.