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An interesting part of the history of the 737 is that when it launched it originally had a serious rudder design flaw that contributed to several fatal crashes

by nrau 7y ago

An interesting part of the history of the 737 is that when it launched it originally had a serious rudder design flaw that contributed to several fatal crashes where a lot of folks lost their lives: https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues However, Boeing did fix the problem, and the 737 went on to be one of the best selling airplanes in history. This MCAS issue is eerily similar in that it has also resulted in two fatal crashes. But if history is any guide, the problems will be fixed, and the memory of MCAS and MAX issues will likely fade from the public as well.

TrueDuality 7y ago
A part of me joins you in this pessimistic view, but the other side of me recognizes that the rudder issues took place in 1991 and most likely the vast majority of the public was never made aware of those issues. I had never heard of it, though that doesn't mean much as a statistical sample. I know a lot of people are now aware of this particular design flaw and I would put money on it being more generally known now then then.
- orisho 7y ago
  I also believe most people hadn't heard of it. For one, news gets around much faster and easier nowadays with the advent of the internet. Anecdotally, it appears as if anyone who flies would've had the right exposure to Western media to hear about it.
- georgeplusplus 7y ago
  You can’t really compare the two. The 80s and 90s were loaded with severe accidents where the NTSB was really giving the taxpayers their money’s worth since there would be a major accident almost every month and the agency had to create a new division to handle all the cases. Most weren’t design issues like the MCAS and the 91’ rudder issue but faulty 3rd party parts, poor maintenance, unknown stresses on aging fleets, pilot issues, and on and on. We are in an unprecedented age of aviation safety and the MCAS issue is a huge blow to that record, thus you’re hearing about it in this level because it is fresh in the news. Accidents were common place back then, so common that I’d wager the 91 crash wasn’t on peoples radars since they just accepted that aircraft crash frequently and to be honest the general public doesn’t know what a rudder is in the first place.
- puranjay 7y ago
  In 1991, the number of deaths in air crashes was also nearly 5x the number of deaths in 2017. A plane crashing in 1991 was, for better or worse, just news. But today, a plane crashing due to an engineering failure is rare enough that it makes headlines that people don't forget easily
  - rangibaby 7y ago
    > A plane crashing in 1991 was, for better or worse, just news. IDK, the Lockerbie and TWA crashes were all over the news for what seemed like years
    - NeedMoreTea 7y ago
      They weren't "just" plane crashes. Most of the follow up surrounded the terrorism and hunt for the bombers...
dreamcompiler 7y ago
The Boeing of those days was a different company than Boeing today, and the public knows it. That Boeing was driven by engineers with safety as their highest priority. Today's Boeing is driven by suits with profit as their highest priority. This Boeing has lost the public's trust. Even if they fix MCAS, how do we know there aren't other safety corners cut in the design just waiting to kill somebody?
- chopin 7y ago
  Not only Boeing lost public trust but presumably the FAA as well. At least outside US this may have even more severe implications. Boeing better not loses one more plane due to design issues.
- dmix 7y ago
  The 1990s of those initial failures also predated the information heavy internet hyper analysis and outrage machines
  - nosianu 7y ago
    It's the messenger's fault. Of course! What arguments do you have that show that lots and lots of articles about about Boeings culture change are all wrong or insignificant (not a contributor to the Max's issues)? I'm also not sure why you think a heuristic that uses amount of outrage as an inverse measure of the validity of an issue is a useful one. I would assume the connection is either non-existent or very weak, meaning you cannot infer anything useful about an issue from how much it is being discussed in the media and in public forums.
    - extempore 7y ago
      You are reading a great deal into an innocuous comment.
    - jakemal 7y ago
      The point of the comment was that people likely cared less because people heard about it significantly less.
SkyMarshal 7y ago
I'm not so sure about that. Besides what was already mentioned about news getting around much faster in 2019 vs 1991, the problems with the Max are harder to fix. It's a fundamentally unstable airframe. The engines are too big and too far forward. They can't fix that without a major redesign of the fuselage to lengthen the landing gear. At which point it may better to simply design and build a whole new airplane.
- jacquesm 7y ago
  > It's a fundamentally unstable airframe. The 737 MAX is not a 'fundamentally unstable airframe', though there are points in the flight envelope where it is close to becoming unstable. The definition of an unstable aircraft is when the center of pressure is forward of the center of gravity, a condition which never occurs in the 747 MAX flight envelope, though it comes perilously close to it in some edge cases. As you correctly identify the engines being 'too big and too far forward' is a factor here, but the most important part of it is the extra lift created by the engine bodies, not the power of the engines themselves.
  - CaptainZapp 7y ago
    Let's just say that Boeing pushed a 50 year old design to places to which it never was supposed to pushed to. Full blown panic about Airbus' offerings had a lot to do with this faithful decision. The first crash was a combination of greed, bad design decisions, rush to market and all that in combination with an FAA that was in Boeing's pocket. The fact that they didn't immediately pulled the plane after the Lion Air crash and the second crash was nothing less than corporate mass murder for profit.
    - AlphaSite 7y ago
      I was under the impression the Max vs a clean room design was actually pushed by airlines, rather than by Boeing it’s self. They wanted a new form scratch design, much like the 787. Now not to remove responsibility from them, ultimately they buckled under pressure and did the deed.
mseidl 7y ago
They should have never made the Max. They need to make a new plane from the ground up. The 737 is ancient.
- mcv 7y ago
  Yeah, the stories about how the new requirements didn't fit the limitations of the 737 design, and how they had to make it unbalanced and correct that inherent instability in software, throws up a bunch of red flags. At some point, you need to accept that the original design doesn't work anymore for the current requirements and redesign the whole thing from scratch. Or at least more thoroughly than the quick & dirty fix they used here.
  - jaywalk 7y ago
    The 737 MAX does not have "inherent instability." The position of the engines causes the plane to pitch up more significantly when power is added. This is not necessarily bad, but it's different enough from the 737 NG that it would have required retraining pilots. MCAS was designed to remove the need for retraining, by using software to make the MAX act like the NG. If everyone would have simply accepted that pilots needed to be retrained for the 737 MAX, MCAS wouldn't have been developed and those planes wouldn't have crashed.
    - sokoloff 7y ago
      You’re right in the first point, but wrong on the second and then maybe right again on the third. There’s a specific federal law concerning the pitch force curve stability (https://www.law.cornell.edu/cfr/text/14/25.173 https://www.law.cornell.edu/cfr/text/14/25.173) that the Max violated, meaning it was not going to be able to be certified as a 737 or as a new, clean sheet airplane, with the demonstrated stick force curve. Now, if you’re going to make a clean sheet design and allow a new type rating, you can change the landing gear and wing design to achieve enough room to set the engines farther back and change the airfoil around them to design a plane that meets 25.173. Boeing already has such a plane: the 757.
- qrbLPHiKpiux 7y ago
jellicle 7y ago
The difference between them is that the rudder flaw could be fixed; once the problem was identified it was a trivial fix. They replaced a single part the size of a soda can. The 737 Max can't be fixed. The engine location unbalances the plane. Full stop. Huge changes to the entire plane must be made to fix that. Software fixes are bandaids and any time the software either fails to activate when it should, or activates when it should not, people die. Unless you think software is 100% infallible, this plane is going to be much less safe than it could have been, forever, unfixably.

by nrau 7y ago

TrueDuality 7y ago

A part of me joins you in this pessimistic view, but the other side of me recognizes that the rudder issues took place in 1991 and most likely the vast majority of the public was never made aware of those issues. I had never heard of it, though that doesn't mean much as a statistical sample. I know a lot of people are now aware of this particular design flaw and I would put money on it being more generally known now then then.

orisho 7y ago
I also believe most people hadn't heard of it. For one, news gets around much faster and easier nowadays with the advent of the internet. Anecdotally, it appears as if anyone who flies would've had the right exposure to Western media to hear about it.
georgeplusplus 7y ago
You can’t really compare the two. The 80s and 90s were loaded with severe accidents where the NTSB was really giving the taxpayers their money’s worth since there would be a major accident almost every month and the agency had to create a new division to handle all the cases. Most weren’t design issues like the MCAS and the 91’ rudder issue but faulty 3rd party parts, poor maintenance, unknown stresses on aging fleets, pilot issues, and on and on. We are in an unprecedented age of aviation safety and the MCAS issue is a huge blow to that record, thus you’re hearing about it in this level because it is fresh in the news. Accidents were common place back then, so common that I’d wager the 91 crash wasn’t on peoples radars since they just accepted that aircraft crash frequently and to be honest the general public doesn’t know what a rudder is in the first place.
puranjay 7y ago
In 1991, the number of deaths in air crashes was also nearly 5x the number of deaths in 2017. A plane crashing in 1991 was, for better or worse, just news. But today, a plane crashing due to an engineering failure is rare enough that it makes headlines that people don't forget easily
- rangibaby 7y ago
  > A plane crashing in 1991 was, for better or worse, just news. IDK, the Lockerbie and TWA crashes were all over the news for what seemed like years
  - NeedMoreTea 7y ago
    They weren't "just" plane crashes. Most of the follow up surrounded the terrorism and hunt for the bombers...

dreamcompiler 7y ago

The Boeing of those days was a different company than Boeing today, and the public knows it. That Boeing was driven by engineers with safety as their highest priority. Today's Boeing is driven by suits with profit as their highest priority. This Boeing has lost the public's trust. Even if they fix MCAS, how do we know there aren't other safety corners cut in the design just waiting to kill somebody?

chopin 7y ago
Not only Boeing lost public trust but presumably the FAA as well. At least outside US this may have even more severe implications. Boeing better not loses one more plane due to design issues.
dmix 7y ago
The 1990s of those initial failures also predated the information heavy internet hyper analysis and outrage machines
- nosianu 7y ago
  It's the messenger's fault. Of course! What arguments do you have that show that lots and lots of articles about about Boeings culture change are all wrong or insignificant (not a contributor to the Max's issues)? I'm also not sure why you think a heuristic that uses amount of outrage as an inverse measure of the validity of an issue is a useful one. I would assume the connection is either non-existent or very weak, meaning you cannot infer anything useful about an issue from how much it is being discussed in the media and in public forums.
  - extempore 7y ago
    You are reading a great deal into an innocuous comment.
  - jakemal 7y ago
    The point of the comment was that people likely cared less because people heard about it significantly less.

SkyMarshal 7y ago

I'm not so sure about that. Besides what was already mentioned about news getting around much faster in 2019 vs 1991, the problems with the Max are harder to fix. It's a fundamentally unstable airframe. The engines are too big and too far forward. They can't fix that without a major redesign of the fuselage to lengthen the landing gear. At which point it may better to simply design and build a whole new airplane.

jacquesm 7y ago
> It's a fundamentally unstable airframe. The 737 MAX is not a 'fundamentally unstable airframe', though there are points in the flight envelope where it is close to becoming unstable. The definition of an unstable aircraft is when the center of pressure is forward of the center of gravity, a condition which never occurs in the 747 MAX flight envelope, though it comes perilously close to it in some edge cases. As you correctly identify the engines being 'too big and too far forward' is a factor here, but the most important part of it is the extra lift created by the engine bodies, not the power of the engines themselves.
- CaptainZapp 7y ago
  Let's just say that Boeing pushed a 50 year old design to places to which it never was supposed to pushed to. Full blown panic about Airbus' offerings had a lot to do with this faithful decision. The first crash was a combination of greed, bad design decisions, rush to market and all that in combination with an FAA that was in Boeing's pocket. The fact that they didn't immediately pulled the plane after the Lion Air crash and the second crash was nothing less than corporate mass murder for profit.
  - AlphaSite 7y ago
    I was under the impression the Max vs a clean room design was actually pushed by airlines, rather than by Boeing it’s self. They wanted a new form scratch design, much like the 787. Now not to remove responsibility from them, ultimately they buckled under pressure and did the deed.

mseidl 7y ago

They should have never made the Max. They need to make a new plane from the ground up. The 737 is ancient.

mcv 7y ago
Yeah, the stories about how the new requirements didn't fit the limitations of the 737 design, and how they had to make it unbalanced and correct that inherent instability in software, throws up a bunch of red flags. At some point, you need to accept that the original design doesn't work anymore for the current requirements and redesign the whole thing from scratch. Or at least more thoroughly than the quick & dirty fix they used here.
- jaywalk 7y ago
  The 737 MAX does not have "inherent instability." The position of the engines causes the plane to pitch up more significantly when power is added. This is not necessarily bad, but it's different enough from the 737 NG that it would have required retraining pilots. MCAS was designed to remove the need for retraining, by using software to make the MAX act like the NG. If everyone would have simply accepted that pilots needed to be retrained for the 737 MAX, MCAS wouldn't have been developed and those planes wouldn't have crashed.
  - sokoloff 7y ago
    You’re right in the first point, but wrong on the second and then maybe right again on the third. There’s a specific federal law concerning the pitch force curve stability (https://www.law.cornell.edu/cfr/text/14/25.173 https://www.law.cornell.edu/cfr/text/14/25.173) that the Max violated, meaning it was not going to be able to be certified as a 737 or as a new, clean sheet airplane, with the demonstrated stick force curve. Now, if you’re going to make a clean sheet design and allow a new type rating, you can change the landing gear and wing design to achieve enough room to set the engines farther back and change the airfoil around them to design a plane that meets 25.173. Boeing already has such a plane: the 757.
qrbLPHiKpiux 7y ago

jellicle 7y ago

The difference between them is that the rudder flaw could be fixed; once the problem was identified it was a trivial fix. They replaced a single part the size of a soda can. The 737 Max can't be fixed. The engine location unbalances the plane. Full stop. Huge changes to the entire plane must be made to fix that. Software fixes are bandaids and any time the software either fails to activate when it should, or activates when it should not, people die. Unless you think software is 100% infallible, this plane is going to be much less safe than it could have been, forever, unfixably.