Boeing 737 Max, an engineering failure?
Boeing is facing significant challenges with its new aircraft.
In the contemporary aviation industry, two major players, Boeing and Airbus, dominate the landscape. However, recent years have seen Boeing facing significant challenges, particularly with its 737 MAX aircraft. Within a span of just over four months, two tragic accidents occurred: the first on Lion Air flight JT610 in October 2018 and the second on Ethiopian Airlines flight ET302 in March 2019. Regrettably, these incidents resulted in the loss of 346 lives.
As reported by Gates (2020) in The Seattle Times, the root cause of these crashes was identified as a malfunctioning sensor triggering the Maneuvering Characteristics Augmentation System (MCAS). The MCAS, designed as a new flight control system, was intended to counteract the aircraft’s tendency to pitch up during specific maneuvers.
According to Perell (2020), during the Lion Air flight 610 on October 29, 2018, the aircraft’s Angle of Attack (AOA) vane feeding MCAS provided a false reading. Tragically, the pilots were unaware of the malfunction caused by Boeing software error. Adding to the complexity, the pilots were not informed about the existence of the MCAS system at all. Boeing justified this decision by stating that MCAS was designed to operate in the background during rare situations, asserting that pilots did not need to be concerned about it. The false AOA signal activated MCAS, causing the aircraft’s nose to pitch down. Despite the pilots’ efforts to regain control, the system activated 26 times, leading to the eventual loss of control and the crash.
In the case of Ethiopian Airlines flight 302, a similar scenario unfolded. The AOA vane indicated a false reading, possibly attributed to a bird strike. The MCAS system activated multiple times, pushing the nose of the jet downward. The aircraft eventually crashed, echoing the tragic outcome of the Lion Air incident.
Flaws of 737 MAX
The design of the 737 MAX has many flaws. The management decisions of Boeing also contribute to the tragedies.
The first design flaw of the MCAS was single point of failure. The MCAS system is activated by a signal from a single sensor, an angle-of-attack (AOA) vane. The jet has two AOA vanes, but only one is used to trigger MCAS during a flight.
This is single point of failure; Boeing should not have depended on the pilots to execute the standard procedure to adjust the tails to reposition the plan. There should always be a backup system.
The second flaw was, MCAS was allowed to be activated repeatedly. This can cause the issue that MCAS constantly fight with the pilots as the pilots try to pull up, but MCAS pushes the nose of the jet down.
As far as the management failures. Boeing made the decision to adapt the old 737 model, which is 50 years old, instead of redesigning the plane to reduce the cost and save time to win orders from airlines.
Boeing did not include the MCAS in the pilot training nor inform the pilots, which caused a huge safety issue.
FAA did not catch the flaws when giving certification to the 737MAX. one former FAA engineer who worked on the MAX certification says, “There wasn’t a complete and proper review of the documents, review was rushed to reach certain certification dates.”
Environment and Stakeholders
The Boeing 737 MAX was designed to meet the demands of the highly competitive commercial aviation market. It aimed to be fuel-efficient, cost-effective, and compliant with all regulatory standards. Key stakeholders included Boeing as the manufacturer, airlines as buyers, and regulatory agencies such as the Federal Aviation Administration (FAA), responsible for aircraft safety. Additional stakeholders encompassed airline passengers, maintenance crews, and pilots as operators.
Engineering processes or concepts related to this system
The flawed design of the MCAS system underscores the need for a more thorough consideration of requirements to eliminate single points of failure.
A robust backup system should be an integral part of critical systems to mitigate the impact of sensor or part failures. The verification and validation process should have identified the flaw that allowed MCAS to be activated repeatedly, causing safety concerns. Careful consideration of how MCAS takes control of the jet is essential to prevent conflicts with pilots.
Communication with pilots regarding the MCAS system was deficient. Given the critical role of MCAS in controlling the airplane, proper training and communication with pilots should have been prioritized. Adequate training would have enabled pilots to manage system failures and prevent conflicts for control.
Conclusion
System engineering plays a pivotal role in the success of any aircraft, and the issues with the 737 MAX could have been identified and addressed earlier through thorough stakeholder analysis, meticulous iterative development, and rigorous testing. By prioritizing stakeholder needs, incorporating iterative processes, and ensuring comprehensive testing, a systematic approach could have significantly contributed to the creation of a safer and more reliable aircraft. This, in turn, would have played a crucial role in preventing the tragic accidents that occurred with the Boeing 737 MAX.
Reference:
Gates, D. (2020). What led to Boeing’s 737 MAX crisis: A Q&A. The Seattle Times. Retrieved from https://www.seattletimes.com/business/boeing-aerospace/what-led-to-boeings-737-max-crisis-a-qa/
Perell, D. (2020). Why Did The Boeing 737 Max Crash? Retrieved from https://perell.com/essay/boeing-737-max/
