“The overriding problem is the basic unstable design of the 737 Max.”
Ralph Nader April 2019
"This airplane is designed by clowns who in turn are supervised by monkeys."
Boeing company employee internal email
On May 25, 2020, I wrote a 109 page report explaining why the real problem with the Boeing 737 Max is that the engine is too high and too far forward – making the plane extremely unstable and requiring a software fix called MCAS to keep the plane from a nose up stall. I predicted that the FAA would not require Boeing to address this real problem of the engine being in the wrong place and instead would allow Boeing to merely add yet another software patch. On August 3, 2020, the FAA issued two reports – both of which signed off on Boeing’s software patch band-aid solution. In this update, we will explain why the new Boeing software patch can actually increase the risk of another plane crash.
We will be referring to the following three reports. If you have not read them yet, you should take a few minutes to read them in order to better understand the safety issues involved as well as the proposed Boeing Band-aid solution. Here is a link to my original 109 page Report:
Here is a link to the August 3 2020 FAA Airworthiness Directive:
Here is a link to the August 3 2020 FAA Summary Report:
Key Band-aids applied to the new 737 Max
The two most surprising aspects of the new 737 Max compared to the version that killed nearly 400 people in a matter of months are:
#1: The initial power of MCAS to tip the Max nose down in the event of a nose up stall was not reduced.
The original version of MCAS was 2.5 degrees in the back of the plane over 10 seconds and the new version of MCAS is still 2.5 degrees in the back of the plane over 10 seconds. Because there is an 8 to 1 lever arm from the back of the plane to the front of the plane, this means that MCAS will drop the nose of the plane 20 degrees (8 times 2.5) over just 10 seconds. This fact alone – that the power of MCAS was not changed - vindicates the claim I made in my original report that the Max was so unstable that any reduction in the power of MCAS would only increase the chances of a nose up stall and plane crash. Boeing is basically admitting that the most powerful version of MCAS is required to prevent a nose up stall and crash.
#2 Despite the admission that MCAS is essential to prevent a nose up stall and crash, Boeing added several conditions that result in MCAS being automatically turned off for the duration of a flight.
For example, if there is a disagreement of more than 5 to 10 degrees between Angle of Attack indicators, MCAS will turn itself off for the rest of the flight. Here is a quote from the Air Worthiness Directive:
If the difference between the AOA sensor inputs is above a calculated threshold, (11) the FCC would disable the speed trim system (STS), including its MCAS function, for the remainder of that flight.
(11) More than 10 degrees difference for more than 10 seconds.
Note: In the summary, the limit is given as 5.5 degrees in some sections and 10 degrees in other sections. Here is a sample quote from the summary report: “An AOA sensor monitor was added to prevent MCAS from using an AOA input if it differs from the other AOA input by more than 5.5 degrees.”
The following quote from the summary report leads to the conclusion that MCAS is turned off at 5..5 degrees while the “Disagree” display light on the panel is turned on at a difference of 10 degrees:
“The AOA DISAGREE light is displayed on the captain’s and first officer’s PFD when the left and right AOA values differ by more than 10 degrees for longer than 10 continuous seconds.”
It does not really matter if MCAS is turned off at 5 degrees or 10 degrees. The essential point is that MCAS should not be turned off at all if it is in fact an essential safety feature.
How can any essential safety system simply be turned off?
Boeing argues that a powerful MCAS is needed to pass FAA certification test flights (which come close to simulating a nose up stall). MCAS is a band-aid added to the 737 Max to compensate for the fact that the MAX engines are placed too far forward and too high in relation to the wings and the center of gravity. MCAS acts like a heavy anvil to keep the nose from tipping too high. But because a powerful MCAS system had led to two crashes, Boeing’s solution is to provide several ways to turn MCAS off – essentially giving the pilots a pair of scissors to cut the heavy anvil band-aid loose if it starts creating problems.
But removing the band-aid also means that for the rest of the flight, there will be no MCAS compensation if a nose up stall occurs. While the biggest risk of an MCAS nose up stall problem is during takeoff and climbing, there are other times when a plane is put in a nose up position – for example, when doing a braking turn on descent into an airport. This would be the worst time for a nose up stall because the airplane would be close to the ground and there would be no time for a pilot to react to correct the problem. The crash would occur within seconds.
How often would Angle of Attack (AOA) indicators disagree by more than 5 to 10 degrees?
The FAA summary document admits that it is common for Angle of Attack indicators to disagree by a small amount. One study concluded that AOA sensor issues occur about 10 times per year in the US – or once every 5 weeks. Over the last five years, 50 flights on US commercial airplanes experienced AoA sensor issues. That is six times above the maximum rate set by the FAA for “hazardous” systems. This is just in the US.
The following study describes several airplane crashes and specifically notes that crashes can occur due to both AOA sensors icing up at the same time: “AOA sensors have not been considered reliable enough for use in flight critical applications. AOA-vanes or pressure probes are subject to icing and mechanical damage that may affect their accuracy and reliability.”
Calculating the time to the next 737 MAX crash
In my previous report, I calculated it that another major crash would occur within one year from the time that the FAA gave the MAX the go ahead to fly again. This was based in part on the fact that there had been two MAX crashes in the previous two years of operation and based also on my assumption that Boeing would place a band-aid on MCAS that would have no significant effect on the real danger – which is that the engines are placed too high up and too far forward on the plane.
It turns out, I was not the only one attempting to estimate when the next MAX crash would occur. In November 2018, after the first MAX crash, the FAA did a secret study in which they concluded that there would be about 15 MAX crashes during the 30 to 45 year life of the plane. This is a crash rate of one MAX crash every 2 to 3 years.
On May 5, 2019, an MIT Statistics professor, Arnold Barnett, estimated that the MAX would crash several times a year. He based his conclusion on the fact that 2 crashes occurred in 2 years when there were only 200 Max planes in operation. He noted that the by the end of 2020, there will be more than 1000 Max planes in operation and eventually, there will be more than 5000 Max planes in operation.
Here are two quotes from his analysis: “In my judgment, Boeing has exhibited a shocking combination of incompetence and deceit and caused what is arguably the worst failure of analytic engineering in the 21st century.”
“As of March 2019, the death risk to passengers who flew the MAX was more than 25 times as high as the worldwide air-passenger death risk from all causes combined over 2008-2017 (approximately 1 in 300,000 versus 1 in 7.9 million).”
In short, a person is 25 times more likely to die flying in a MAX than while flying in an Airbus NEO.
How will the Corona Virus Lockdown affect Max Crashes?
US airlines carried 96% fewer scheduled service passengers in April 2020 than in April 2019, according to data filed with the Bureau of Transportation Statistics (BTS). International travel declined by an even larger amount (98%). As long as the travel bans remain in effect, it is likely that there will be no plane crashes. However, at some point, our human immune system will gain natural immunity to the corona virus and some day, travel will resume. When normal travel resumes, and when there are more than 1000 MAX planes operating with takeoffs and landings about 3 times per day for each MAX, I continue to predict that a MAX crash will occur within one year.
Only One in Five Americans willing to Risk their Lives Flying on the MAX
Two surveys in June 2019 found that the majority of Americans are not interested in being the next MAX victims. A study of 2,000 US travelers by the Atmosphere Research Group found 70% would hesitate to book a flight on the Boeing 737 MAX. A separate UBS Evidence Lab survey of 1,000 respondents similarly found 70% would think twice about flying on the aircraft. Only 14% said they would fly the 737 MAX within six months of its return to service. Atmosphere president Henry Harteveldt said: “Travelers aren’t merely scared of the 737 MAX, they are terrified of it. The 737 MAX is for now a plane that passengers do not want to fly.”
These two surveys were obviously done before Americans found out that the FAA had concluded that 15 MAX planes would crash in the next 30 to 45 years.
What about the other “safety improvements”
Boeing has claimed that it is making other safety improvements intended to cut down on the number of Max crashes. For example, instead of MCAS going off every few seconds, Boeing claims that MCAS will be limited to one 20 degree nose dive and then turn itself off. Here is a quote from the Airworthiness Directive: “The revised flight control laws would permit only one activation of MCAS per sensed high AOA event. A subsequent activation of MCAS would be possible only after the airplane returns to a low AOA state.”
What the above claim fails to note is that the whole point of MCAS activation is to reduce the AOA angle from 20 degrees to zero degrees. Therefore, the MAX will automatically be in a low AOA state after activation is completed and another MCAS cycle can begin immediately. The claim that MCAS is being limited to one cycle is simply not true.
To make matters even worse, Boeing claims that the new MCAS will also push the nose of the plane up after it has pushed the nose of the plane down. The danger here is that if MCAS is wrong about the actual position of the nose of the plane, pushing the nose up could actually lead to a nose up stall and crash. In short, making MCAS more complex – adding band-aids on top of band-aids - does not reduce the danger, it increases it.
The Worst Crime Committed by Boeing
Killing people by the hundreds by building a dangerous airplane is not even the worst crime committed by Boeing. As I explained in my previous report, Boeing has for years been robbing one million children in Washington state of their right to an education by demanding billions of dollars in tax breaks. These illegal tax breaks mean that struggling students in Washington state are forced to endure some of the highest class sizes and lowest school funding in the nation. These billions of dollars in illegal tax breaks are still being given to Boeing – whose business model is based on a culture of extreme shortsighted greed and rampant corruption. The two “rubber-stamping” reports issued by the FAA on August 3, 2020 are simply another example of how deeply this greed and corruption has infected our state and federal governments.
Answers to Five Questions
Here are answers to some questions that have been raised regarding the article I published on May 25, 2019:
#1 Fifteen months after publishing the article, would you continue to claim that Boeing will go bankrupt?
Yes. The majority of the public already do not want to be the next MAX victim. Because Boeing has refused to address the real problem, the fact that the engines are in the wrong place, it is certain there will be another crash. When there is another crash, whatever trust any of the flying public may have in Boeing will be gone for good. No airplane manufacturer can exist for long without the trust of the flying public.
#2 Throughout history, the aviation industry has always used accidents as a learning opportunity to improve the engineering of its aircraft. But your article suggests that this will not happen with 737 Max. Why? What has changed?
What has changed, as I explain in several sections of my original article is that Boeing has changed from a company whose goal was to make a safe airplane to a company dominated by greed and corruption – which broke the most basic safety rules in order to increase profit margins by billions of dollars. As long as this culture of extreme greed and corruption is allowed to exist, there will be more MAX crashes.
#3 The Boeing 737 Max is undergoing extensive recertification within global authorities. Do you think this is insufficient to guarantee the safety of the aircraft?
As I explained in my May 25, 2019 article, the engines of the MAX are in the wrong place. These engines create turbulence when at an angle of attack of more than 15 degrees. To avoid this turbulence, Boeing engineers were forced to create the monstrous MCAS program to bring the nose back down. Putting a band-aid or even several band-aids on MCAS does not change the underlying problem – which is that the engines are in the wrong place. As I have explained in this update, I think that the changes made by Boeing, and especially turning off MCAS, will actually make the new MAX version even more crash prone that the original MAX version.
#4 In your opinion, how should Boeing act to solve the problem of the 737 Max? Do you see any alternative for the company to return to lead the aviation market?
Boeing should have never attempted to put the new larger engine on a very old plane design. Instead, Boeing should have done what Airbus did by designing a plane that was high enough off the ground to put the engines in the correct place – under the wing where it would not cause excessive turbulence.
Boeing failed to do this in 2011. Boeing had a second chance in 2016 when the initial testing revealed that the MAX was much less stable than originally predicted. Instead of canceling the MAX program in 2016, Boeing simply increased the power of MCAS by a factor of 5.
Boeing again had a chance to cancel the MAX program after the first MAX crash in November 2018. Instead, Boeing ignored the underlying problem and keep making a very dangerous plane.
Boeing again had a chance to cancel the MAX program after the second MAX crash in March 2019. Instead, Boeing ignored the underlying problem and keep making a very dangerous plane.
At this point, it is too late for Boeing. They have no option but to keep making bad planes until the next crash finally leads to not only the death of 200 more passengers, but also to the death of Boeing.
#5 Some critics claim that you do not have the technical knowledge necessary to make the statements you made in the article. What do you have to say about this?
As I pointed out in my May 2019 report, I do have a Major in Physics from Washington State University. However, the calculations in my report are not complex and do not require a major in Physics. Anyone with even a single basic first year introductory course in Newtonian Physics ought to be able to understand that moving the engines forward and up one foot in relationship to the center of gravity will have a huge effect on the stability of the plane.
What is complex is the subject of Turbulence – which is why I included in my original report quotes from two Nobel Prize winners in Physics – Richard Feynman and Werner Heisenberg - both of whom claimed that Turbulence is more complex than Quantum Mechanics.
My claim is that the Boeing engineers who originally designed the MAX did not properly account for turbulence – because there is no equation to account for turbulence. This is why the power of MCAS had to be increased by a factor of five in 2016 after the initial test flights began.
But my real technical knowledge is not merely in Physics. It is in Problem Solving. I spent nearly 20 years teaching courses in Problem Solving at Bellevue College (only a few miles from all three Boeing plants in Washington State). I have had more than 100 Boeing engineers in my problem solving courses. Even smart engineers can be fooled by a topic as complex as turbulence. No amount of training can qualify anyone to deal accurately with this topic.
A key aspect of problem solving is to identify the underlying cause of the problem you are trying to solve and then address the underlying problem rather than merely putting band-aids on the surface symptoms. Here is a quote from my May 2019 report:
“Problem Solving 101 – Identify the Underlying Cause of the Problem In order to solve any problem, it is important to focus on the underlying cause of the problem. The underlying problem of the Boeing 737 Max is that moving the large and powerful new engines too far forward in front of the wings and too high up in front of the wings caused the 737 Max to have an extreme tendency to have the nose of the plane tip up too high. This extreme nose up position is just as dangerous as an extreme nose down position because extreme nose up can lead to a stall and loss of control of the airplane just as extreme nose down can lead to a dive and loss of control of the airplane.”
“It is the fact that the 737 Max has the engine placed too far in front of and above the wing that leads to the conclusion that the 737 Max is the most unstable commercial airplane ever built. There is no solution for this problem other than to stop making the 737 Max and replace it with an entirely new airplane designed to be far enough off the ground so that the engines can be put in a more stable position.”
Rather than attacking my credentials, it would be more useful for critics to challenge some of the specific claims I made in either my original report or in this updated report.
The fact that not a single specific claim in my original report has been challenged – despite having been reviewed by thousands of people - is evidence that my claims were and still are accurate.
Even with the changes made by Boeing in the past year, the MAX remains the most unstable commercial airplane ever mass produced. Because the engines are still in the wrong place, I am certain there will be another MAX crash at some point in the near future. When this crash occurs, no sane person will be willing to risk their life flying on a MAX – and that will be the end of Boeing.
As always, I look forward to your questions and comments.
David Spring M. Ed.
spring for schools at gmail dot com