Content area
Full Text
SAFETY AND AUTOMATION
In March 2019, Boeing 737 MAX 8 and MAX 9 aircraft were grounded in more than 41 countries, including the United States, Canada, and China, after an Ethiopian Airlines crash resulted in the deaths of everyone on board. This was the second deadly crash involving a Boeing 737 MAX. A Lion Air (Indonesia) Boeing 737 MAX 8 crashed in October 2018, also killing everyone on board. As a result of these two incidents, Boeing paused delivery of these planes, although production continues. The Boeing 737 MAX story provides an alarming case study on the interrelationships between software and systems engineering, human factors, corporate behavior, and customer service. Although both crashes are still under investigation, and definitive answers are forthcoming, this article examines the events from the perspectives of safety and software quality and proposes five lessons practitioners can apply to their own projects to mitigate risk.
KEY WORDS
complex systems, risk, risk mitigation, safety, software quality, systems thinking
INTRODUCTION
The Boeing 737 is the best-selling aircraft in the world, with more than 15,000 planes sold. After Airbus announced an upgrade to the A320 that provided 14 percent better fuel economy per seat, Boeing responded with the 737 MAX. It was marketed as an upgrade to the famed 737 design, using larger engines to match the improved fuel efficiency from Airbus. Boeing claimed the 737 MAX was so similar to the original 737 that pilots already licensed for this aircraft would not need additional training and simulator time for the 737 MAX.
Because Boeing increased the engine size to improve fuel efficiency, the engines had to be positioned higher on the wings and slightly forward of the old position. Higher nose landing gear was also added to provide the same ground clearance. The larger engines and new positions destabilized the aircraft, but not under all conditions. The engine housings are designed so they do not generate lift in normal flight. However, if the airplane is in a steep pitch (for example, takeoff or a hard turn), the engine housings generate more lift than on previous 737 models. Depending on the angle, the airplane's inertia can cause the plane to over-swing into a stall.
To address increased stall risk, Boeing developed a software...