If you have already read my first post, you will have head of this system before, but you may still be unaware of some of the causes and effects of its implementation on the Boeing 737 MAX airplane as a whole. If not, I will reintroduce the basic idea of the system. The Maneuvering Characteristics Augmentation System (MCAS) is a primarily software driven approach to “enhance the pitch stability of the airplane – so that it feels and flies like other 737s (“737 MAX Software Update”).”
In theory, this concept is perfect. Not only can pilots fly the newest airplane systems, they can do so with confidence because it will feel like airplanes that they are already used to. In the most basic of explanations, MCAS is meant to reduce the risk of the airplane undergoing stall conditions.
Stall conditions are where the wing is being flown at an angle of attack (the angle with which the leading edge makes with the free stream air flowing over and around it) that is above the angle where the flow of air around the wing will continue producing lift that is equivalent to the weight of the airplane. If the force of gravity on the jet is greater than the upward force of lift produced by the wing, the airplane will begin to descend. The problem with a descent under stall is that it is extremely difficult to control and regain the correct angle and airspeed in order to keep the airplane in the sky.
To reduce the likelihood of such an event occurring on the 737 MAX, MCAS uses sensors onboard the airplane to judge when the angle of attack has reached potentially dangerous levels, or when very steep turns are being performed and intervenes by pushing the nose down in an attempt to counteract whatever caused the airplane to get close to stall. In the event that the pilot wants to override the system, they are able to manually trim the airplane in order to achieve the effects that they desire. (Ostrower)
So where is the problem? All of this information sounds very good and the system as a whole should be preventing airplane crashes if anything, right? As is inevitable with the 737 MAX situation at this point, not everything is as it appears. With pilots who were untrained in the new software and malfunctions that became more prevalent than expected, MCAS had flaws. Two of the major causes of these faults included the angle of attack sensor which was used by the software to determine flight conditions and the wiring through the airplane which was subject to failure.
Angle of attack sensors on airplanes have been commonplace for many years, and honestly, also not the most reliable of equipment for that same amount of time. With the 737 MAX, Boeing felt that they had developed a method that was more reliable than the industry standard, and which could be counted on for other important airplane systems including MCAS. Unfortunately, these thoughts proven to be false. Instead of failing after the prescribed 10 million flight hours, these sensors ultimately ended up needing to be replaced every 1.7 million flight hours. Over the past five years, this amounted to a total of 50 flights in the United States alone. (Campbell) By having a critical flight system such as MCAS based upon an unreliable sensor, the concept as a whole is flawed. In essence, this would be like trying to measure a mile exactly by counting the number of steps you take. Could it work? Maybe. Would it be perfect? Definitely not.
The other issue surrounding MCAS involved wiring throughout the airplane itself. If the angle of attack sensor was not bad enough, now imagine that the parts surrounding it and allowing it to work were also susceptible to failure. In the investigation of the 737 MAX since it has been grounded, it was discovered that there is a possibility of creating a short circuit near the rear of the airplane where two wiring bundles come close together. While it is still unknown whether this is a cause of any of the crashes, its concept is still worrying. If the bundles were to short circuit each other, sensor data in the horizontal and vertical tail could be interrupted and cause MCAS to interpret the information as an issue and begin to push the nose up or down. Without knowing proper procedure in the case of such an event, pilots would be unable to recover control of their aircraft. (Kitroeff)
MCAS has come under great scrutiny in the media, and for good reason, it has its flaws. What is important to remember here is whether or not the system was implemented with the proper protocol, the intentions were clear, MCAS would save an airplane from stall in situations that the pilot may not realize a problem was occurring and it would allow the airplane to feel similar to the other jets that pilots were comfortable with. Boeing did not intend for such a system to have so many points of failure, even so, MCAS could be a contributing factor in hundreds of deaths and therefore is worth review.
References:
“737 MAX Software Update.” Boeing, www.boeing.com/commercial/737max/737-max-software-updates.page.
Campbell, Darryl. “The Many Human Errors That Brought down the Boeing 737 Max.” The Verge, The Verge, 2 May 2019, www.theverge.com/2019/5/2/18518176/boeing-737-max-crash-problems-human-error-mcas-faa.
Kitroeff, Natalie, and David Gelles. “It’s Not Just Software: New Safety Risks Under Scrutiny on Boeing’s 737 Max.” The New York Times, The New York Times, 5 Jan. 2020, www.nytimes.com/2020/01/05/business/boeing-737-max.html.
Ostrower, Jon. “What Is the Boeing 737 Max Maneuvering Characteristics Augmentation System?” The Air Current, 28 Aug. 2019, theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/.
I don’t really know too much about planes so I’m fascinated to learn something new about the 737 MAX each time I read your blog posts. While I’m not very informed on information surrounding airplanes, because I travel so much I’m usually intrigued to learn more whenever I hear about new policies regarding this mode of transport. My interest to know more about the MCAS system caused me to do some research and I came across an article that put a great amount of blame on Boeing for the deaths of many in the 737 MAX crashes.
This article published by The Verge claimed that the tragic events associated with the 737 MAX were a result of a number of human errors. While the first error mentioned does not relate to the MCAS system, it states that Boeing’s first mistake took place nearly a decade ago when they rushed the completion of the 737 MAX due to competition with Airbus. This rush in production apparently led to many corners being cut and ultimately the production of an unsafe aircraft. Another point which the article mentions is the fact that because the 737 MAX “was the same plane type as its predecessors,” pilots would only need 2.5 hours of training via iPad to operate the 737 MAX.
When it comes to criticism about the MCAS system, The Verge claims that Boeing along with the FAA failed to inform pilots that MCAS existed in addition to not regulating the system to make it safer. Boeing did not even mention the MCAS system in its amended type certification of the 737 MAX. Another extreme criticism of Boeing is that they did not require formal training of the MCAS system but instead “only recommended a 30-minute self-study course for pilots.” I find this extremely shocking that Boeing did not work harder to train pilots of the 737 MAX on the details of the system, whether it was a flawed system or not.
The most mind-blowing part of this article to me was that both Boeing and the FAA refuse to admit any wrongdoing when it comes to the improper training and regulation of the MCAS system. It seems to me as if Boeing was purely focused on making money through making a more appealing aircraft in its competition with Airbus regardless of its safety.
Source:
https://www.theverge.com/2019/5/2/18518176/boeing-737-max-crash-problems-human-error-mcas-faa
Great post Cole, this is certainly an interesting topic! What I found interesting was the communication after failed MCAS systems and the resulting societal effects. According to David Slotnick at Business Insider, “Jim Marko, the manager in aircraft integration and safety assessment at Transport Canada Civil Aviation, wrote that the ‘only way I see moving forward at this point, is that MCAS has to go,'” (Slotnick). However, currently at the time, Boeing wants to improve the MCAS system rather than remove it. They believe they can fix the problem even after “crashes in Indonesia and Ethiopia killed 346 people” (Slotnick). The question that should be asked, is whether Boeing should keep the system or not?
As understood in the article, the MCAS systems were added to automatically adjust for the large engine size of the 737 Boeing. This would allow for less training and experience for pilots. And in the event of a crash, the MCAS systems would fail, making the plane immediately nose dive. Those unprepared pilots would not be able to stop the aircraft from plummeting out of the sky. Ultimately, the crashes are a result of a system failure and unprepared pilots. Boeing proposed a great solution that would allow for cheaper pilot implementation for easier flying. However, not all technology is perfect, it is the process of trial and error.
Many, like Marko, believe that the problem begins before the system implementation. According to Slotnick, Marko’s email reported “‘MCAS introduces catastrophic hazards that weren’t there before,’ and that ‘it and the fix add to much complexity’ “(Slotnick). It seems that Marko from the beginning had a distrust of the framework of the MCAS system. Although, they appear to be a great idea, Marko supports the problem that many Pilots aren’t prepared to deal with technological failures.
In such a technological driven world, it will be interesting to see the implementations of other high-tech sensors. There may be initial problems immediately, and through trial and error, how accepting will society be? Certainly with Boeing, almost no one is accepting at the moment. Will we have self-driving cars and truck that won’t have these malfunctions. Who knows?
Source:
https://www.businessinsider.com/boeing-737-max-mcas-canada-aviation-regulator-leaked-email-2019-11
Hey Cole! This blog was a really interesting read for me. I am definitely not interested in engineering at all, but the way you formulated and presented the information in a really simplistic and approachable sense made it fun to read. I decided to research the topic a little bit more outside of your post and found that a fair amount of people are acknowledging the failures of Boeing, but also the failures of the airline industry itself specifically with undertrained pilots.
The New York Times had a super interesting article focusing on a crash in Indonesia where it chronicles the mystery of it all. The entire encounter that they describe seems super confusing and open ended; it seems as if neither side, the pilots or ground control, knew what was happening. There was a distinct lack of proper communication between the two and that ultimately lead to the demise of the plane. Though, the pilot himself was reportedly maltrained and his copilot was not much more knowledgeable than himself. The article went into depth about how the airline industry itself demands new pilots all the times and often undertrains their workers, especially with smaller airlines. This demand then grows in more developing regions such as Indonesia where these new airlines and the usage of them grows for the first time in history, causing a rushed and frail training process.
The crazy complexity of this scandal that I didn’t even know anything about, it remarkable to me. It makes me think, however, that since there are lethal issues from so many different areas, that there needs to be major reform in the industry. They would need to focus on better regulations for pilot training across the board since this problem affects every flight, transcending the Boeing 737 MAX issue. The other reform would need to focus on the planes themselves, requiring more intense cross-company checks and making sure that every aspect and new implementation is fully functional.
https://www.nytimes.com/2019/09/18/magazine/boeing-737-max-crashes.html
Hey Cole, I really liked your blog this week. I thought the organization was very strong and easy to follow for readers. I liked how you gave a little information to review since it has been a while since your last blog. Following that, I think it was nice how you started stating the pros, and then moving to the drawbacks, and finally letting the reader think about the issue. Like I said before, I know little to nothing about planes, but I was still able to follow along and remain engaged with the content. When it comes to this issue, we were actually discussing something similar in my psychology class. We were thinking about self driving cars, which is obviously different from MCAS but bI think there is an interesting parallel when it comes to the morality of it. The dilemma we discussed was if a self driving car was on its path, and suddenly someone crossed the street, would it be programmed to save the pedestrian or save the driver of the car. This dilemma also assumes that death is inevitable, the car cannot avoid one person’s death without killing the other person. This sparked quite a debate within our class and everyone had a range of viewpoints from the car should always save the driver to the car should always save the pedestrian and everywhere in between. What I got out of this discussion/dilemma was that we should just not have self driving cars. After reading your blog I can say I feel similarly to MCAS. Although it sounds like a good plan, it theoretically should keep more people safe. However, because of what has already happened in this situation, I feel as though it will be safer to not implement MCAS until scientists know that it will not pose any risk. Looking forward to the next blog!
Worked Cited:
https://www.nature.com/articles/d41586-018-07135-0