--- title: "MCAS: The Silent Killer on the 737 MAX – How Boeing's Cost Cutting Claimed 346 Lives" description: "When cost cutting claimed 346 lives\n\nWe like to think that the modern aviation industry is incredibly safe, and make no mistake, it typically is, as statistically flying is consistently the safest mode of transport by a considerable margin. It just so happens that when something does go wrong, it goes wrong on a scale that is simply not seen elsewhere and produces simply shockingly long lists of fatalities.\n\nWhen such accidents do occur, we typically take solace in the fact that while aviation accidents are undeniably tragic, they are at least understandable and typically not the result of corporate negligence; a safety rule worked in a way that no one could have imagined, a component failed in a way that no one could have imagined and so and so forth, and as a result of these no-fault tragedies lessons are learned, and aviation becomes even safer as a result.\n\nBut sometimes, ever so rarely, aviation disasters occur that *were* the result of corporate negligence, and people are killed in ways that were knowingly completely avoidable, all so that a corporation could cut corners and increase its profitability.\n\nToday we will be exploring one such tragic instance: The Boeing 737-MAX, and the 346 people who had to die as a result of Boeing's ill-conceived cost cutting MCAS system.\n\n## History of the 737\n\nOne of the most shocking aspects of this story is how it occurred on the 737 of all things – a venerable age-old airliner that prior to the rolling out of the MAX had a stellar safety record. Therefore, to properly understand this tragedy, we must appreciate what made the MAX so different from its forerunners, so let's go back to the beginning.\n\nBoeing unveiled the first model of the 737 in 1964, with its first flight occurring in 1967. Since then, it has transformed radically, and become the most popular jet airliner in the world, with 15,572 being sold as of the time of writing.\n\nThe first mass produced model, the 737-200 entered commercial service in 1968. Originally built to supplement the 727 on shorter routes, it had a passenger capacity of 85 to 130 and was powered by the state-of-the-art Pratt & Whitney JT8D engine. 1,144 examples were sold, and despite their age, they still soldier on in service to this day.\n\nThe 737 Classic series was launched over a decade later in 1980 and consists of the 300, 400, and 500 variants. It offered an enhanced seat capacity, glass cockpit, and new (much larger) CFM 56-3 turbofan engines. The series proved popular among airlines, as a total of 1,988 airframes have been produced since its launch. Like its older siblings, the classic series is still serving happily with many airliners all over the world.\n\nThe Next Generation (NG) line, the 737's third series, was launched just a few short years after the 737-500 embarked on commercial operations in 1990. The NG series consists of the 600, 700, 800, and 900 variants, with the Boeing 737-800 being the best-selling model of them all. It incorporated enhanced new features, including upgraded CFM56-7 engines and an enhanced glass cockpit featuring six large information and flight displays. The NG proved to be the most commercially successful 737 yet, with 7,096 examples having been delivered when production ended in 2019.\n\nThe 737 has also had its fair share of unorthodox variants. With examples including the 737-700C, which is intended to be quickly convertible between passenger and cargo configurations. It is based on the 737-700 fuselage with the addition of a forward cargo door. It certainly proved versatile, being able to carry up to 149 passengers in the passenger layout, or up to 18.8 tonnes of cargo in the cargo configuration. Another unorthodox variant is the C40A, a US Navy airlift aircraft derived from the 737-700C, featuring flexible configurations that can carry 120 passengers or eight pallets of cargo, or a combination of three cargo pallets and 70 passengers. The 737 also has its share of more militarised variants, with an example being the 737 AEW&C, an airborne early warning and control (AWAC) aircraft operated by various governments around the world, with another example being the P-8 Poseidon, a long-range maritime patrol and reconnaissance aircraft based on the 737-800 that has been sold to seven different countries.\n\nBoeing has even made business jets from the 737 platform. The first such design, the BBJ1 was first delivered in 1998. It was based on the 737-700 model, but includes some features from other 737NG variants, such as a reinforced landing gear and an increased range. The BBJ2 was then launched in 1999 and delivered for the first time in 2001. It was based on the 737-800 model and offered an expanded range and 25% more cabin space than the BBJ1. The current BBJ3, first introduced in 2009 is larger still, being based on the 737-900ER, but orders for this model so far have been few and far between.\n\n## The 737-MAX\n\nThis brings us to the 737-Max, Boeing's attempt at modernising its venerable twin-engine mainstay for the 21st century. Its development was the direct consequence of the Airbus A320 Neo, the latest variant of the 737's main competitor, which was announced all the way back in 2006, and promised a radical redesign that promised to make it one of the most fuel efficient narrow-bodies in the sky. This naturally terrified Boeing; fuel efficiency is by far and away the single greatest sales pitch for an airline manufacturer, as in the narrow profit margin world of aviation, a 0.1% increase in efficiency can equate to millions saved from an operational budget in a single year.\n\nSo, eager not to see their sales completely dry up, Boeing started work on an A320 Neo competitor immediately. Initially, its engineers wanted to put the 737 out to pasture and instead come up with a brand new \"clean sheet\" design, one that would incorporate the many improvements in airliner efficiency that had been developed since the 1960s from the ground up, rather than being essentially jury rigged to an old core concept; creating something that would have eventually resembled a 787 Dreamliner scaled down to a narrow-body design. The Boeing executives however did not like this idea at all, it was projected to be much too expensive, so instead, the Boeing engineers were ordered to proceed with a further bodged 737.\n\nRemember this penny-pinching attitude from the Boeing executives… it will be very important later.\n\nIt is also worth noting that when we talk of a 'jury rigged' and 'bodged' 737, this is of course tongue in cheek and hyperbolic to drive home the point that the basic design elements of the new aircraft remained that of its 1960s forerunner. Note further, that while it may have been a decision made to save the time and expense of designing a brand-new aircraft, a hell of a lot of work is still involved in 'simply' upgrading a design, so the MAX still differs from its predecessors in many ways.\n\nIn terms of aerodynamic differences, the Max features a new design element called the \"split-tip\" Advanced Technology Winglet, which aims to decrease vortex drag, increase fuel efficiency, and maximize lift while staying within the same ICAO aerodrome reference code as older 737s. When compared to the 737-NG, which only had a blended winglet, a MAX carrying 162 passengers on a 3,000 mile (5,600 km) flight has 1.8% better fuel burn, a significant improvement.\n\nThe MAX also features other aerodynamic improvements, including a re-contoured tail cone, revised auxiliary power unit inlet and exhaust, and the removal of aft-body vortex generators. These small improvements further improve the plane's fuel efficiency.\n\nThe structure of the MAX also changed significantly from earlier models. The Boeing 737 MAX incorporates several design changes, one of which is the 8-inch (20 cm) taller nose-gear strut, which maintains the same 17-inch (43 cm) ground clearance of previous 737 engine nacelles. The new struts and nacelles for the heavier engines add weight, and as a result, the main landing gear and supporting structure have been reinforced, and the fuselage skins are thicker in some areas. This adds 6,500 pounds (2,900 kg) to the MAX 8's empty aircraft weight, and to maintain fuel and payload capacity, its maximum take-off weight is 7,000 lb (3,200 kg) heavier.\n\nProbably the most significant change of all was to the MAX's engines; CFM International LEAP-1B's, rather than the CFM International CFM56 and Pratt & Whitney JT8D used on the recent 737-800, and much older 737-200 respectively. Look at these engines side by side, and the difference becomes immediately apparent, the newer engines are much, much broader, and as a result, they are much, much more efficient.\n\nThis may sound contradictory at first, after all, if you put a bigger engine in your car, it becomes less economical right? But the CFM International LEAP-1B is big on account of its high bypass ratio, not simply through being an enormous turbojet. Bypass ratio here refers to the comparison between the mass flow rate of air drawn into the engine through the fan disk that goes around the engine core with the mass flow rate of the air that goes through the engine core; put simply, the CFM-LEAP is a traditional turbofan engine, with a very, very big fan on the front, this sucks air in and around the engine, which then contributes to thrust by being sent out of the back. This makes a high bypass engine incredibly efficient, as you're basically getting more thrust for free, as the bypassed air helps to generate additional thrust without burning fuel.\n\nHigh bypass engines were nothing new to the Boeing 737 with the MAX however, as if we compare this 737-200 from the 1960s and this 737-800 from the 2000s, we can clearly see its engines were already getting bigger; but still the Boeing executives wanted more, they were insistent that the MAX was to have an even greater engine still – but how? Its base design hailed from the 1960s when turbofans were sleek and petite things with low bypass ratios, and as a result its wings were low to the ground, leaving only so much room to install bigger engines as the years went on…\n\nThe solution was to place the engines further forward and higher on the wings compared to previous models, freeing up more clearance for that ever-important high bypass ratio.\n\nThis change in engine placement changed the aerodynamic characteristics of the MAX and created a tendency to pitch up in certain flight conditions, particularly during high-angle-of-attack manoeuvres.\n\nTo address this issue, Boeing, rather than doing an extensive aerodynamic redesign of the airplane, decided the quickest and least expensive fix for the flight characteristics of the MAX was to provide a new software system. Called the Maneuver Characteristics Augmentation System (MCAS), this is a piece of software which automatically compensates for the altered flight characteristics of the MAX, making it (theoretically at least) fly in the same manner as previous 737-NGs from the pilots perspective. In more technical terms, the MCAS supplements traditional pilot warning mechanisms such as a \"stick shaker\" and stall warning system with an automatic system that will automatically drive the stabilizer trim to force the nose down when sensor data indicates a dangerously high angle of attack. This system relied on data from the aircraft's angle-of-attack sensor to detect when the aircraft was in danger of stalling and would then adjust the horizontal stabilizer to push the nose of the aircraft down and maintain a safe angle-of-attack – Remember this as we go on… it will prove important.\n\nAll of these changes appeared to perform well in testing, and so the 737-MAX formally entered service on the 22nd of May 2017 with Indonesian Malindo Air. It proved to be a hit, and soon orders flooded in. The aforementioned Malindo Air ordered 16 MAX's, with the biggest customers being the American United and Southwest Airlines, who ordered 419 and 384 examples respectively. This was followed by the Emirati flydubai and Lion Air who both ordered 251 examples, followed by Irish Ryanair, who ordered 210.\n\nJob well done for Boeing then! They had managed to modernise the 737 on the cheap and the orders were flooding in. The executives, most of whom had never held neither a flight stick nor a spanner in their lives, could award themselves a nice big juicy bonus and a well-earned pat on the back.\n\nOr so they thought… until 737-MAX's started crashing.\n\n## The Crashes\n\nOn the 29th of October 2018 Lion Air Flight 610, operated by a 737-MAX, went down with the loss of all souls aboard.\n\nThe pilots of Lion Air Flight 610 were experienced, with the captain having over 6,000 flight hours and the first officer having over 5,000. As they took off from Jakarta, all seemed well, but just a few minutes into the flight – disaster struck. The aircraft's angle of attack (AOA) sensor, which measures the angle between the wing and the oncoming air, had malfunctioned and was sending conflicting data to the aircraft's flight control systems. This caused the aircraft's MCAS system to believe that it was in a stall, when it was not.\n\nThe pilots attempted to troubleshoot the problem, but they were unable to diagnose the root cause of the issue. They contacted the airline's maintenance team on the ground for assistance, but the team was not able to provide any additional guidance. So, with their options exhausted, the crew attempted to return to Jakarta Airport.\n\nIt was to no avail however; the MAX continued to believe it was in a stall, and eventually the MCAS system took over, and when it believed it had pitched down enough to be flying level it was actually pointing straight at the ground. The pilots tried to manually counteract the MCAS system by pulling back on the control yoke, but they were ultimately unsuccessful.\n\nAs the aircraft continued to descend, the pilots frantically searched for a solution, but they were unable to regain control of the plane. The aircraft crashed into the Java Sea at a speed of approximately 450 miles per hour, just 13 minutes after take-off. The impact was catastrophic, and there were no survivors among the 189 passengers and crew on board.\n\nThis tragedy was further compounded on the 10th of March 2019, when Ethiopian Airlines Flight 302, also being operated by a 737-MAX, one that in fact had only been in service for a few months, took off from Addis Ababa, Ethiopia, bound for Nairobi, Kenya.\n\nAs the plane climbed, the crew began to experience issues with the aircraft's angle of attack sensors, just like the crew of Lion Air 610 before them. The faulty sensors were once again giving incorrect readings, indicating that the plane's nose was too high, which of course… triggered the MCAS system, which pitched the nose of the aircraft down to prevent what it believed to be an imminent stall.\n\nThe crew tried to manually adjust the plane's angle of attack by pulling the control column, but the MCAS continued to push the plane's nose down repeatedly. This resulted in a battle between the pilots and the MCAS system, and the plane began to dive towards the ground.\n\nAs the pilots tried to counteract the downward pitching of the nose, they reportedly followed Boeing's recommended procedures, which involved disabling the MCAS and using manual trim to control the plane's altitude, but no good came of it. The plane continued to oscillate and dive, reaching speeds of up to 575 miles per hour, and ultimately crashed into the ground with tremendous force.\n\nAll 157 people on board the flight were killed, including passengers from more than 30 countries, many of whom were on their way to attend a major United Nations environmental conference in Nairobi.\n\nTwo aircraft of the same type going down in such quick succession, and in such similar ways had the aviation world spooked. The entire MAX fleet worldwide was grounded by the 18th of March 2019, and a worldwide investigation effort was launched to get to the bottom of the matter, and what it uncovered… was shocking.\n\n## The Investigation\n\nThe American Federal Aviation Administration launched a Joint Authorities Technical Review (JATR) team to evaluate the certification process for the Boeing 737-MAX's flight control systems in March 2019. The JATR team included representatives from the FAA, NASA, and nine other international aviation authorities, highlighting the global ramifications of the crashes and the urgent need to restore confidence in the regulatory system.\n\nOne of the most glaring issues uncovered with the MCAS was its reliance on data from a single AOA sensor. By depending solely on one sensor, the MCAS system was rendered vulnerable to erroneous inputs. If the AOA sensor malfunctioned or provided inaccurate data, the MCAS would still respond, potentially causing the system to activate inappropriately and forcing the aircraft's nose down, as it did in both Lion Air Flight 610 and Ethiopian Airlines Flight 302.\n\nInvestigators also discovered that the MCAS system was designed to activate multiple times, with each activation capable of adjusting the stabilizer's position further. This repetitive activation, especially in cases of erroneous sensor data, could lead to a continuous downward pitch of the aircraft, making it increasingly difficult for pilots to regain control and counteract the system's actions.\n\nThis discovery was just the tip of the iceberg however, as it was also discovered that inadequate training and documentation regarding the system had been provided to pilots. Boeing had downplayed the significance of the MCAS system during the certification process, asserting that pilots would not require extensive additional training. Consequently, many pilots were completely unaware of the system's existence.\n\nThe lack of comprehensive training materials and simulator sessions left pilots ill-prepared to deal with unexpected MCAS activations. In both the Lion Air and Ethiopian Airlines crashes, flight crews struggled to diagnose and respond to the relentless nose-down commands from the MCAS, ultimately losing control of the aircraft.\n\nThe investigation's findings made it clear that the MCAS system, initially intended as a safety-enhancing feature, had become a critical vulnerability due to its design flaws, reliance on a single AOA sensor, and insufficient pilot training.\n\nWith such horrific revelations having emerged, attention naturally then went to trying to understand how such a flawed system was ever certified in the first place, and to answer this the investigation delved deeper into the intricate relationship between Boeing and the FAA, unearthing systemic flaws that ultimately contributed to the 737-MAX tragedies.\n\nOne of the critical aspects that came under intense scrutiny was the FAA's Organization Designation Authorization (ODA) program. This program enabled aircraft manufacturers, such as Boeing, to perform certain certification tasks on the FAA's behalf, ostensibly to streamline the certification process and make it more efficient. However, this practice raised red flags, with many questioning its overall effectiveness and implications for safety.\n\nCritics of the ODA program argued that it created an inherent conflict of interest, as Boeing, a private corporation with a vested interest in accelerating the certification process and maximizing profits, was essentially allowed to act as both the manufacturer and regulator of the 737-MAX. This arrangement facilitated a troubling culture within Boeing, where the pressure to expedite the delivery of the 737-MAX and compete with rival Airbus took precedence over thorough safety assessments and rigorous testing.\n\nThe FAA's decision to allow Boeing to assess the safety of the MCAS without adequate oversight proved to be a pivotal misstep. Due to the lack of independent validation, Boeing's assurances that the MCAS was safe and that pilots required minimal additional training went largely unchallenged. The FAA's reliance on Boeing's expertise, coupled with the inadequacy of its own internal oversight mechanisms, had created an environment ripe for disaster.\n\nWorse still, it became evident that Boeing had exploited the cosy relationship between themselves and the FAA to bypass the normal lengthy certification process for its MCAS system.\n\nBoeing's internal communications were also investigated, and they painted a damning picture of the corporate culture within Boeing. Employees were found to have mocked regulators, downplayed the significance of the MCAS system, and even boasted about their ability to circumvent regulatory scrutiny. In some instances, engineers openly questioned the 737-MAX's safety and expressed concerns about the pressure to prioritize production deadlines over rigorous safety evaluations, only to be shot down by Boeing's corporate leadership.\n\nHarrowing though these revelations were, a clear picture of the disaster had now been uncovered: Boeing executives were well aware that they had engineered a dangerous MCAS system, and manipulated its cosy relationship with FAA regulators to get it pushed through regardless – all so they could increase their profits, safety be damned!\n\n## The Consequences\n\nWhen the results of the investigation were made public Boeing faced a storm of media backlash, and faced a collapse in public trust that it still appears to have not recovered from. Far more concerning for Boeing executives however was the legal fallout, and the potential for it to get very, very expensive.\n\nThey have faced numerous lawsuits from the families of the victims of the crashes, as well as from shareholders and airlines that were affected by the grounding of the MAX fleet. In addition, the US Department of Justice also launched a criminal investigation into the company's handling of the MAX development and certification process.\n\nBoeing has already agreed to pay over billions in fines and settlements related to the scandal. This includes a $2.5 billion settlement with the US Department of Justice, comprising a $243.6 million criminal penalty, $1.77 billion in compensation for airlines, and $500 million for a crash-victim beneficiary's fund. The company has also settled with the families of many of the victims, though some lawsuits are still ongoing.\n\nThe scandal has also led to regulatory changes, with the US Federal Aviation Administration (FAA) and other aviation regulators around the world implementing new requirements for aircraft certification and oversight. The FAA has faced criticism for its role in certifying the 737-MAX and has promised to make changes to its certification process in response to the scandal.\n\nThe legal fallout from the 737-MAX MCAS scandal is likely to continue for years to come, as the families of the victims and other stakeholders continue to seek justice and accountability.\n\n## Conclusion\n\nIn the shadow of the Boeing 737-MAX MCAS scandal, we are left to ponder the sombre lessons that echo through the aviation industry. The tragic loss of 346 lives stands as a haunting testament to the catastrophic consequences that can arise when corporate ambition, regulatory evasion, and design missteps collide. As we remember the victims of Lion Air Flight 610 and Ethiopian Airlines Flight 302, we must also confront the unsettling reality that the pursuit of profit and competitive advantage can come at a devastating human cost. It is now incumbent upon the aviation industry, regulators, and lawmakers alike to ensure that the lessons learned from this dark chapter in aviation history are never forgotten. The future of air travel demands a renewed commitment to safety, transparency, and accountability – for only then can we begin to restore the public's trust and confidence in the miracle of flight.\n\n## Key Takeaways\n\n- The Boeing 737-MAX crashes were due to a flawed MCAS system designed to compensate for engine placement changes.\n- Boeing's cost-cutting measures and pressure to compete with Airbus led to inadequate safety assessments and testing.\n- The MCAS system's reliance on a single angle-of-attack sensor made it vulnerable to erroneous inputs, causing fatal crashes.\n- Insufficient pilot training and documentation on the MCAS system contributed to the pilots' inability to regain control.\n- The cozy relationship between Boeing and the FAA allowed the flawed MCAS system to bypass rigorous certification processes.\n\n## Frequently Asked Questions\n\n### What is the MCAS system on the Boeing 737-MAX?\n\nThe Maneuver Characteristics Augmentation System (MCAS) is a software system designed to automatically compensate for the altered flight characteristics of the 737-MAX, making it fly similarly to previous 737-NGs from the pilots' perspective. It adjusts the horizontal stabilizer to push the nose of the aircraft down to maintain a safe angle-of-attack.\n\n### How many people died as a result of the Boeing 737-MAX MCAS issues?\n\n346 people died as a result of the Boeing 737-MAX MCAS issues.\n\n### What were the two major crashes involving the Boeing 737-MAX?\n\nThe two major crashes were Lion Air Flight 610 on October 29, 2018, and Ethiopian Airlines Flight 302 on March 10, 2019.\n\n### What was the cause of the Lion Air Flight 610 crash?\n\nThe crash was caused by a malfunctioning angle-of-attack (AOA) sensor that sent conflicting data to the aircraft's flight control systems, triggering the MCAS to push the nose down repeatedly, leading to a loss of control.\n\n### What regulatory changes were implemented after the Boeing 737-MAX crashes?\n\nThe US Federal Aviation Administration (FAA) and other aviation regulators around the world implemented new requirements for aircraft certification and oversight. The FAA promised to make changes to its certification process in response to the scandal.\n\n### What was the FAA's Organization Designation Authorization (ODA) program?\n\nThe ODA program allowed aircraft manufacturers like Boeing to perform certain certification tasks on behalf of the FAA, which raised concerns about conflicts of interest and the effectiveness of safety assessments.\n\n### What were the financial consequences for Boeing due to the MCAS scandal?\n\nBoeing agreed to pay over $2.5 billion in fines and settlements, including a $243.6 million criminal penalty, $1.77 billion in compensation for airlines, and $500 million for a crash-victim beneficiary’s fund.\n\n### What was the initial response of Boeing executives to the 737-MAX's success?\n\nBoeing executives awarded themselves bonuses and pats on the back for the success of the 737-MAX, believing they had modernized the 737 on the cheap and secured numerous orders.\n\n### What was the primary issue with the MCAS system?\n\nThe MCAS system relied on data from a single angle-of-attack (AOA) sensor, making it vulnerable to erroneous inputs. If the sensor malfunctioned, the MCAS could activate inappropriately and force the aircraft's nose down.\n\n### What was the role of the FAA in the certification of the Boeing 737-MAX?\n\nThe FAA allowed Boeing to assess the safety of the MCAS system with inadequate oversight, relying on Boeing's expertise and downplaying the need for extensive pilot training. This created an environment where safety assessments were compromised.\n\n## Sources\n\n- [Original MegaProjects video: MCAS: The Silent Killer on the 737 MAX](https://www.youtube.com/watch?v=VYpvLRAwnU4)\n- [Hero image source](https://upload.wikimedia.org/wikipedia/commons/e/e8/N704AL_2023-10-28_KBFI.jpg) by Nick Dean / openverse, by-sa.\n\n## Related Coverage" url: https://megaprojects.pub/article/mcas-silent-killer-737-max.md canonical: https://megaprojects.pub/article/mcas-silent-killer-737-max datePublished: 2026-06-16 dateModified: 2026-06-16 author: - name: Simon Whistler url: https://megaprojects.pub/author/simon-whistler publisher: MegaProjects image: "https://media.megaprojects.pub/cdn-cgi/image/width=600,height=338,fit=cover,quality=80,format=auto/articles/VYpvLRAwnU4/hero.jpg" type: NewsArticle contentHash: edb49d4594a23783a735527b5fc6caa5ccf52fb908d945e6b6d312eed301886b tokens: 6884 summaryUrl: https://megaprojects.pub/article/mcas-silent-killer-737-max.md.summary.md --- When cost cutting claimed 346 lives We like to think that the modern aviation industry is incredibly safe, and make no mistake, it typically is, as statistically flying is consistently the safest mode of transport by a considerable margin. It just so happens that when something does go wrong, it goes wrong on a scale that is simply not seen elsewhere and produces simply shockingly long lists of fatalities. When such accidents do occur, we typically take solace in the fact that while aviation accidents are undeniably tragic, they are at least understandable and typically not the result of corporate negligence; a safety rule worked in a way that no one could have imagined, a component failed in a way that no one could have imagined and so and so forth, and as a result of these no-fault tragedies lessons are learned, and aviation becomes even safer as a result. But sometimes, ever so rarely, aviation disasters occur that *were* the result of corporate negligence, and people are killed in ways that were knowingly completely avoidable, all so that a corporation could cut corners and increase its profitability. Today we will be exploring one such tragic instance: The Boeing 737-MAX, and the 346 people who had to die as a result of Boeing's ill-conceived cost cutting MCAS system. ## History of the 737 One of the most shocking aspects of this story is how it occurred on the 737 of all things – a venerable age-old airliner that prior to the rolling out of the MAX had a stellar safety record. Therefore, to properly understand this tragedy, we must appreciate what made the MAX so different from its forerunners, so let's go back to the beginning. Boeing unveiled the first model of the 737 in 1964, with its first flight occurring in 1967. Since then, it has transformed radically, and become the most popular jet airliner in the world, with 15,572 being sold as of the time of writing. The first mass produced model, the 737-200 entered commercial service in 1968. Originally built to supplement the 727 on shorter routes, it had a passenger capacity of 85 to 130 and was powered by the state-of-the-art Pratt & Whitney JT8D engine. 1,144 examples were sold, and despite their age, they still soldier on in service to this day. The 737 Classic series was launched over a decade later in 1980 and consists of the 300, 400, and 500 variants. It offered an enhanced seat capacity, glass cockpit, and new (much larger) CFM 56-3 turbofan engines. The series proved popular among airlines, as a total of 1,988 airframes have been produced since its launch. Like its older siblings, the classic series is still serving happily with many airliners all over the world. The Next Generation (NG) line, the 737's third series, was launched just a few short years after the 737-500 embarked on commercial operations in 1990. The NG series consists of the 600, 700, 800, and 900 variants, with the Boeing 737-800 being the best-selling model of them all. It incorporated enhanced new features, including upgraded CFM56-7 engines and an enhanced glass cockpit featuring six large information and flight displays. The NG proved to be the most commercially successful 737 yet, with 7,096 examples having been delivered when production ended in 2019. The 737 has also had its fair share of unorthodox variants. With examples including the 737-700C, which is intended to be quickly convertible between passenger and cargo configurations. It is based on the 737-700 fuselage with the addition of a forward cargo door. It certainly proved versatile, being able to carry up to 149 passengers in the passenger layout, or up to 18.8 tonnes of cargo in the cargo configuration. Another unorthodox variant is the C40A, a US Navy airlift aircraft derived from the 737-700C, featuring flexible configurations that can carry 120 passengers or eight pallets of cargo, or a combination of three cargo pallets and 70 passengers. The 737 also has its share of more militarised variants, with an example being the 737 AEW&C, an airborne early warning and control (AWAC) aircraft operated by various governments around the world, with another example being the P-8 Poseidon, a long-range maritime patrol and reconnaissance aircraft based on the 737-800 that has been sold to seven different countries. Boeing has even made business jets from the 737 platform. The first such design, the BBJ1 was first delivered in 1998. It was based on the 737-700 model, but includes some features from other 737NG variants, such as a reinforced landing gear and an increased range. The BBJ2 was then launched in 1999 and delivered for the first time in 2001. It was based on the 737-800 model and offered an expanded range and 25% more cabin space than the BBJ1. The current BBJ3, first introduced in 2009 is larger still, being based on the 737-900ER, but orders for this model so far have been few and far between. ## The 737-MAX This brings us to the 737-Max, Boeing's attempt at modernising its venerable twin-engine mainstay for the 21st century. Its development was the direct consequence of the Airbus A320 Neo, the latest variant of the 737's main competitor, which was announced all the way back in 2006, and promised a radical redesign that promised to make it one of the most fuel efficient narrow-bodies in the sky. This naturally terrified Boeing; fuel efficiency is by far and away the single greatest sales pitch for an airline manufacturer, as in the narrow profit margin world of aviation, a 0.1% increase in efficiency can equate to millions saved from an operational budget in a single year. So, eager not to see their sales completely dry up, Boeing started work on an A320 Neo competitor immediately. Initially, its engineers wanted to put the 737 out to pasture and instead come up with a brand new "clean sheet" design, one that would incorporate the many improvements in airliner efficiency that had been developed since the 1960s from the ground up, rather than being essentially jury rigged to an old core concept; creating something that would have eventually resembled a 787 Dreamliner scaled down to a narrow-body design. The Boeing executives however did not like this idea at all, it was projected to be much too expensive, so instead, the Boeing engineers were ordered to proceed with a further bodged 737. Remember this penny-pinching attitude from the Boeing executives… it will be very important later. It is also worth noting that when we talk of a 'jury rigged' and 'bodged' 737, this is of course tongue in cheek and hyperbolic to drive home the point that the basic design elements of the new aircraft remained that of its 1960s forerunner. Note further, that while it may have been a decision made to save the time and expense of designing a brand-new aircraft, a hell of a lot of work is still involved in 'simply' upgrading a design, so the MAX still differs from its predecessors in many ways. In terms of aerodynamic differences, the Max features a new design element called the "split-tip" Advanced Technology Winglet, which aims to decrease vortex drag, increase fuel efficiency, and maximize lift while staying within the same ICAO aerodrome reference code as older 737s. When compared to the 737-NG, which only had a blended winglet, a MAX carrying 162 passengers on a 3,000 mile (5,600 km) flight has 1.8% better fuel burn, a significant improvement. The MAX also features other aerodynamic improvements, including a re-contoured tail cone, revised auxiliary power unit inlet and exhaust, and the removal of aft-body vortex generators. These small improvements further improve the plane's fuel efficiency. The structure of the MAX also changed significantly from earlier models. The Boeing 737 MAX incorporates several design changes, one of which is the 8-inch (20 cm) taller nose-gear strut, which maintains the same 17-inch (43 cm) ground clearance of previous 737 engine nacelles. The new struts and nacelles for the heavier engines add weight, and as a result, the main landing gear and supporting structure have been reinforced, and the fuselage skins are thicker in some areas. This adds 6,500 pounds (2,900 kg) to the MAX 8's empty aircraft weight, and to maintain fuel and payload capacity, its maximum take-off weight is 7,000 lb (3,200 kg) heavier. Probably the most significant change of all was to the MAX's engines; CFM International LEAP-1B's, rather than the CFM International CFM56 and Pratt & Whitney JT8D used on the recent 737-800, and much older 737-200 respectively. Look at these engines side by side, and the difference becomes immediately apparent, the newer engines are much, much broader, and as a result, they are much, much more efficient. This may sound contradictory at first, after all, if you put a bigger engine in your car, it becomes less economical right? But the CFM International LEAP-1B is big on account of its high bypass ratio, not simply through being an enormous turbojet. Bypass ratio here refers to the comparison between the mass flow rate of air drawn into the engine through the fan disk that goes around the engine core with the mass flow rate of the air that goes through the engine core; put simply, the CFM-LEAP is a traditional turbofan engine, with a very, very big fan on the front, this sucks air in and around the engine, which then contributes to thrust by being sent out of the back. This makes a high bypass engine incredibly efficient, as you're basically getting more thrust for free, as the bypassed air helps to generate additional thrust without burning fuel. High bypass engines were nothing new to the Boeing 737 with the MAX however, as if we compare this 737-200 from the 1960s and this 737-800 from the 2000s, we can clearly see its engines were already getting bigger; but still the Boeing executives wanted more, they were insistent that the MAX was to have an even greater engine still – but how? Its base design hailed from the 1960s when turbofans were sleek and petite things with low bypass ratios, and as a result its wings were low to the ground, leaving only so much room to install bigger engines as the years went on… The solution was to place the engines further forward and higher on the wings compared to previous models, freeing up more clearance for that ever-important high bypass ratio. This change in engine placement changed the aerodynamic characteristics of the MAX and created a tendency to pitch up in certain flight conditions, particularly during high-angle-of-attack manoeuvres. To address this issue, Boeing, rather than doing an extensive aerodynamic redesign of the airplane, decided the quickest and least expensive fix for the flight characteristics of the MAX was to provide a new software system. Called the Maneuver Characteristics Augmentation System (MCAS), this is a piece of software which automatically compensates for the altered flight characteristics of the MAX, making it (theoretically at least) fly in the same manner as previous 737-NGs from the pilots perspective. In more technical terms, the MCAS supplements traditional pilot warning mechanisms such as a "stick shaker" and stall warning system with an automatic system that will automatically drive the stabilizer trim to force the nose down when sensor data indicates a dangerously high angle of attack. This system relied on data from the aircraft's angle-of-attack sensor to detect when the aircraft was in danger of stalling and would then adjust the horizontal stabilizer to push the nose of the aircraft down and maintain a safe angle-of-attack – Remember this as we go on… it will prove important. All of these changes appeared to perform well in testing, and so the 737-MAX formally entered service on the 22nd of May 2017 with Indonesian Malindo Air. It proved to be a hit, and soon orders flooded in. The aforementioned Malindo Air ordered 16 MAX's, with the biggest customers being the American United and Southwest Airlines, who ordered 419 and 384 examples respectively. This was followed by the Emirati flydubai and Lion Air who both ordered 251 examples, followed by Irish Ryanair, who ordered 210. Job well done for Boeing then! They had managed to modernise the 737 on the cheap and the orders were flooding in. The executives, most of whom had never held neither a flight stick nor a spanner in their lives, could award themselves a nice big juicy bonus and a well-earned pat on the back. Or so they thought… until 737-MAX's started crashing. ## The Crashes On the 29th of October 2018 Lion Air Flight 610, operated by a 737-MAX, went down with the loss of all souls aboard. The pilots of Lion Air Flight 610 were experienced, with the captain having over 6,000 flight hours and the first officer having over 5,000. As they took off from Jakarta, all seemed well, but just a few minutes into the flight – disaster struck. The aircraft's angle of attack (AOA) sensor, which measures the angle between the wing and the oncoming air, had malfunctioned and was sending conflicting data to the aircraft's flight control systems. This caused the aircraft's MCAS system to believe that it was in a stall, when it was not. The pilots attempted to troubleshoot the problem, but they were unable to diagnose the root cause of the issue. They contacted the airline's maintenance team on the ground for assistance, but the team was not able to provide any additional guidance. So, with their options exhausted, the crew attempted to return to Jakarta Airport. It was to no avail however; the MAX continued to believe it was in a stall, and eventually the MCAS system took over, and when it believed it had pitched down enough to be flying level it was actually pointing straight at the ground. The pilots tried to manually counteract the MCAS system by pulling back on the control yoke, but they were ultimately unsuccessful. As the aircraft continued to descend, the pilots frantically searched for a solution, but they were unable to regain control of the plane. The aircraft crashed into the Java Sea at a speed of approximately 450 miles per hour, just 13 minutes after take-off. The impact was catastrophic, and there were no survivors among the 189 passengers and crew on board. This tragedy was further compounded on the 10th of March 2019, when Ethiopian Airlines Flight 302, also being operated by a 737-MAX, one that in fact had only been in service for a few months, took off from Addis Ababa, Ethiopia, bound for Nairobi, Kenya. As the plane climbed, the crew began to experience issues with the aircraft's angle of attack sensors, just like the crew of Lion Air 610 before them. The faulty sensors were once again giving incorrect readings, indicating that the plane's nose was too high, which of course… triggered the MCAS system, which pitched the nose of the aircraft down to prevent what it believed to be an imminent stall. The crew tried to manually adjust the plane's angle of attack by pulling the control column, but the MCAS continued to push the plane's nose down repeatedly. This resulted in a battle between the pilots and the MCAS system, and the plane began to dive towards the ground. As the pilots tried to counteract the downward pitching of the nose, they reportedly followed Boeing's recommended procedures, which involved disabling the MCAS and using manual trim to control the plane's altitude, but no good came of it. The plane continued to oscillate and dive, reaching speeds of up to 575 miles per hour, and ultimately crashed into the ground with tremendous force. All 157 people on board the flight were killed, including passengers from more than 30 countries, many of whom were on their way to attend a major United Nations environmental conference in Nairobi. Two aircraft of the same type going down in such quick succession, and in such similar ways had the aviation world spooked. The entire MAX fleet worldwide was grounded by the 18th of March 2019, and a worldwide investigation effort was launched to get to the bottom of the matter, and what it uncovered… was shocking. ## The Investigation The American Federal Aviation Administration launched a Joint Authorities Technical Review (JATR) team to evaluate the certification process for the Boeing 737-MAX's flight control systems in March 2019. The JATR team included representatives from the FAA, NASA, and nine other international aviation authorities, highlighting the global ramifications of the crashes and the urgent need to restore confidence in the regulatory system. One of the most glaring issues uncovered with the MCAS was its reliance on data from a single AOA sensor. By depending solely on one sensor, the MCAS system was rendered vulnerable to erroneous inputs. If the AOA sensor malfunctioned or provided inaccurate data, the MCAS would still respond, potentially causing the system to activate inappropriately and forcing the aircraft's nose down, as it did in both Lion Air Flight 610 and Ethiopian Airlines Flight 302. Investigators also discovered that the MCAS system was designed to activate multiple times, with each activation capable of adjusting the stabilizer's position further. This repetitive activation, especially in cases of erroneous sensor data, could lead to a continuous downward pitch of the aircraft, making it increasingly difficult for pilots to regain control and counteract the system's actions. This discovery was just the tip of the iceberg however, as it was also discovered that inadequate training and documentation regarding the system had been provided to pilots. Boeing had downplayed the significance of the MCAS system during the certification process, asserting that pilots would not require extensive additional training. Consequently, many pilots were completely unaware of the system's existence. The lack of comprehensive training materials and simulator sessions left pilots ill-prepared to deal with unexpected MCAS activations. In both the Lion Air and Ethiopian Airlines crashes, flight crews struggled to diagnose and respond to the relentless nose-down commands from the MCAS, ultimately losing control of the aircraft. The investigation's findings made it clear that the MCAS system, initially intended as a safety-enhancing feature, had become a critical vulnerability due to its design flaws, reliance on a single AOA sensor, and insufficient pilot training. With such horrific revelations having emerged, attention naturally then went to trying to understand how such a flawed system was ever certified in the first place, and to answer this the investigation delved deeper into the intricate relationship between Boeing and the FAA, unearthing systemic flaws that ultimately contributed to the 737-MAX tragedies. One of the critical aspects that came under intense scrutiny was the FAA's Organization Designation Authorization (ODA) program. This program enabled aircraft manufacturers, such as Boeing, to perform certain certification tasks on the FAA's behalf, ostensibly to streamline the certification process and make it more efficient. However, this practice raised red flags, with many questioning its overall effectiveness and implications for safety. Critics of the ODA program argued that it created an inherent conflict of interest, as Boeing, a private corporation with a vested interest in accelerating the certification process and maximizing profits, was essentially allowed to act as both the manufacturer and regulator of the 737-MAX. This arrangement facilitated a troubling culture within Boeing, where the pressure to expedite the delivery of the 737-MAX and compete with rival Airbus took precedence over thorough safety assessments and rigorous testing. The FAA's decision to allow Boeing to assess the safety of the MCAS without adequate oversight proved to be a pivotal misstep. Due to the lack of independent validation, Boeing's assurances that the MCAS was safe and that pilots required minimal additional training went largely unchallenged. The FAA's reliance on Boeing's expertise, coupled with the inadequacy of its own internal oversight mechanisms, had created an environment ripe for disaster. Worse still, it became evident that Boeing had exploited the cosy relationship between themselves and the FAA to bypass the normal lengthy certification process for its MCAS system. Boeing's internal communications were also investigated, and they painted a damning picture of the corporate culture within Boeing. Employees were found to have mocked regulators, downplayed the significance of the MCAS system, and even boasted about their ability to circumvent regulatory scrutiny. In some instances, engineers openly questioned the 737-MAX's safety and expressed concerns about the pressure to prioritize production deadlines over rigorous safety evaluations, only to be shot down by Boeing's corporate leadership. Harrowing though these revelations were, a clear picture of the disaster had now been uncovered: Boeing executives were well aware that they had engineered a dangerous MCAS system, and manipulated its cosy relationship with FAA regulators to get it pushed through regardless – all so they could increase their profits, safety be damned! ## The Consequences When the results of the investigation were made public Boeing faced a storm of media backlash, and faced a collapse in public trust that it still appears to have not recovered from. Far more concerning for Boeing executives however was the legal fallout, and the potential for it to get very, very expensive. They have faced numerous lawsuits from the families of the victims of the crashes, as well as from shareholders and airlines that were affected by the grounding of the MAX fleet. In addition, the US Department of Justice also launched a criminal investigation into the company's handling of the MAX development and certification process. Boeing has already agreed to pay over billions in fines and settlements related to the scandal. This includes a $2.5 billion settlement with the US Department of Justice, comprising a $243.6 million criminal penalty, $1.77 billion in compensation for airlines, and $500 million for a crash-victim beneficiary's fund. The company has also settled with the families of many of the victims, though some lawsuits are still ongoing. The scandal has also led to regulatory changes, with the US Federal Aviation Administration (FAA) and other aviation regulators around the world implementing new requirements for aircraft certification and oversight. The FAA has faced criticism for its role in certifying the 737-MAX and has promised to make changes to its certification process in response to the scandal. The legal fallout from the 737-MAX MCAS scandal is likely to continue for years to come, as the families of the victims and other stakeholders continue to seek justice and accountability. ## Conclusion In the shadow of the Boeing 737-MAX MCAS scandal, we are left to ponder the sombre lessons that echo through the aviation industry. The tragic loss of 346 lives stands as a haunting testament to the catastrophic consequences that can arise when corporate ambition, regulatory evasion, and design missteps collide. As we remember the victims of Lion Air Flight 610 and Ethiopian Airlines Flight 302, we must also confront the unsettling reality that the pursuit of profit and competitive advantage can come at a devastating human cost. It is now incumbent upon the aviation industry, regulators, and lawmakers alike to ensure that the lessons learned from this dark chapter in aviation history are never forgotten. The future of air travel demands a renewed commitment to safety, transparency, and accountability – for only then can we begin to restore the public's trust and confidence in the miracle of flight. ## Key Takeaways - The Boeing 737-MAX crashes were due to a flawed MCAS system designed to compensate for engine placement changes. - Boeing's cost-cutting measures and pressure to compete with Airbus led to inadequate safety assessments and testing. - The MCAS system's reliance on a single angle-of-attack sensor made it vulnerable to erroneous inputs, causing fatal crashes. - Insufficient pilot training and documentation on the MCAS system contributed to the pilots' inability to regain control. - The cozy relationship between Boeing and the FAA allowed the flawed MCAS system to bypass rigorous certification processes. ## Frequently Asked Questions ### What is the MCAS system on the Boeing 737-MAX? The Maneuver Characteristics Augmentation System (MCAS) is a software system designed to automatically compensate for the altered flight characteristics of the 737-MAX, making it fly similarly to previous 737-NGs from the pilots' perspective. It adjusts the horizontal stabilizer to push the nose of the aircraft down to maintain a safe angle-of-attack. ### How many people died as a result of the Boeing 737-MAX MCAS issues? 346 people died as a result of the Boeing 737-MAX MCAS issues. ### What were the two major crashes involving the Boeing 737-MAX? The two major crashes were Lion Air Flight 610 on October 29, 2018, and Ethiopian Airlines Flight 302 on March 10, 2019. ### What was the cause of the Lion Air Flight 610 crash? The crash was caused by a malfunctioning angle-of-attack (AOA) sensor that sent conflicting data to the aircraft's flight control systems, triggering the MCAS to push the nose down repeatedly, leading to a loss of control. ### What regulatory changes were implemented after the Boeing 737-MAX crashes? The US Federal Aviation Administration (FAA) and other aviation regulators around the world implemented new requirements for aircraft certification and oversight. The FAA promised to make changes to its certification process in response to the scandal. ### What was the FAA's Organization Designation Authorization (ODA) program? The ODA program allowed aircraft manufacturers like Boeing to perform certain certification tasks on behalf of the FAA, which raised concerns about conflicts of interest and the effectiveness of safety assessments. ### What were the financial consequences for Boeing due to the MCAS scandal? Boeing agreed to pay over $2.5 billion in fines and settlements, including a $243.6 million criminal penalty, $1.77 billion in compensation for airlines, and $500 million for a crash-victim beneficiary’s fund. ### What was the initial response of Boeing executives to the 737-MAX's success? Boeing executives awarded themselves bonuses and pats on the back for the success of the 737-MAX, believing they had modernized the 737 on the cheap and secured numerous orders. ### What was the primary issue with the MCAS system? The MCAS system relied on data from a single angle-of-attack (AOA) sensor, making it vulnerable to erroneous inputs. If the sensor malfunctioned, the MCAS could activate inappropriately and force the aircraft's nose down. ### What was the role of the FAA in the certification of the Boeing 737-MAX? The FAA allowed Boeing to assess the safety of the MCAS system with inadequate oversight, relying on Boeing's expertise and downplaying the need for extensive pilot training. This created an environment where safety assessments were compromised. ## Sources - [Original MegaProjects video: MCAS: The Silent Killer on the 737 MAX](https://www.youtube.com/watch?v=VYpvLRAwnU4) - [Hero image source](https://upload.wikimedia.org/wikipedia/commons/e/e8/N704AL_2023-10-28_KBFI.jpg) by Nick Dean / openverse, by-sa. ## Related Coverage