Question 11: Boeing used SE to develop the 737 MAX aircraft. Does that suggest the SE process is flawed?
Answer: No. The problems with the 737 MAX aircraft did not occur because of a flaw in the SE process, but because Boeing did not rigorously apply the SE process during its development.
Additional Information: The Boeing 737 MAX was grounded in March 2019 after two fatal crashes. The 737 MAX is the fourth generation of the 737 aircraft. The first three generations entered service in 1966, 1984, and 1996, and the MAX was introduced in 2017.
Boeing originally planned to replace the third-generation 737 with a “clean-sheet” design. However, in 2011, Airbus launched the A320neo (new engine option). Within six months, Airbus had sold more than 1,000 aircraft, setting a record and taking sales away from the 737. To meet Airbus’ challenge, Boeing abandoned its plan to develop a clean-sheet aircraft and instead created the MAX by upgrading the third-generation 737 and installing new, larger, more efficient engines.
Boeing decided to mount the new (larger) engines forward and upward from the wings rather than increase the aircraft height enough to accommodate the engines under the wings. As a result, the 737 MAX’s nose pitches upward when engine thrust is increased.
To prevent a stall, Boeing added a maneuvering characteristics augmentation system (MCAS). The design of the MCAS relied on a single angle-of-attack instrument. When that instrument failed (as it did in both accidents) and erroneously indicated that the aircraft was about to stall, the MCAS repeatedly commanded the nose down.
Boeing did not include a description of the MCAS in the flight crew operations manual, which is the basis for airlines' documentation and training. As a result, flight crews did not train for MCAS failure, did not realize that MCAS failure could cause a crash, and did not know how to recognize and recover from MCAS failure.
These problems suggest serious flaws in Boeing’s management and SE processes during the 737 MAX’s development. As expected, Boeing is taking action to improve its management and SE processes. The 737 MAX crashes did not raise questions about the value of the SE process itself; rather, they showed how failure to rigorously apply the SE process can lead to extremely negative consequences.
Lawmakers and the public are (justifiably) critical of Boeing for these crashes and the process failures that led to them. However, in their zeal to criticize Boeing, lawmakers should realize that the lessons learned apply to them as well. Congress and the president need to develop robust bipartisan processes (such as SE) to effectively govern the country. The broken tax, health care, immigration, justice, and education systems should spur them to action and cause them to improve their processes, just as Boeing is taking action to improve its processes.