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When I found out about MAX and what happened with the design, after leaving that industry, I was amazed it had gotten approved. That number there indicates tha

When I found out about MAX and what happened with the design, after leaving that industry, I was amazed it had gotten approved. That number there indicates that.

TheBigSalad 3y ago
Wasn't the cause a software bug that was fixed and not a design issue?
- rawgabbit 3y ago
  It's not a bug. Boeing deliberately chose to mislead the airlines and pilots on what they were doing and used software to hide the fact. On top of that there was no redundancy for the single indicator which triggers the nose down/pitch down. The software issues is downstream of the managerial malfeasance.
- JumpCrisscross 3y ago
  It was a regulatory bottleneck prompting an inefficient design that required a software fix to fly, which relied mortally on the inputs from a sensor that was optionally non-redundant outside the United States.
  - mechhacker 3y ago
    Yep. They were trying to compensate for different feel/behavior to the pilots without additional training. I really don't see how that was approved by a competent agency... Ended up in those two horrible crashes in perfectly good airplanes.
    - JumpCrisscross 3y ago
      > don't see how that was approved by a competent agency The version that flies in America has two AoA sensors. To my knowledge, those planes didn't have a problem.
      - wkat4242 3y ago
        Don't forget a lot of countries rely on the FAA for guidance because they don't all have the resources or manufacturer access to thoroughly evaluate an aircraft themselves. Also, even with two AoA sensors the pilot had to switch to the alternate because the MCAS wouldn't know which one was right. This is why usually 3 sensors are used in redundant systems.
    - MilStdJunkie 3y ago
      Because when you're a DER (Designated Engineering Representative), you're still getting your paycheck from Boeing, and being a fussy DER is not a fast track to success. I can't lay down too much more specifics, but anecdotally, that's how things go, and not just at Boeing either. Seen it at a lot of suppliers too. You're a "good" DER, or you're on the short list next round of layoffs[1]. DERs have been getting more and more sign off authority on increasingly critical core airworthiness systems, stuff no one would have dreamed of delegating to a DER twenty years ago. The actual full time agency people, well, depends on how much they're fishing for a corner office. But by and large, they were hardasses, thank God. All three of them. Particularly the EUROCAE Dutch guys. Whew! But none of this is important as the Boeing culture, which . . ehhhhhhyyyyuuuuuchhh . . could use some improvements. To phrase it one way. [1] There's always layoffs, good times and bad, because everything is funded contract to contract, week to week. I had a goddamn amazing analog engineer get pink slipped, packed his stuff, and then - after all that - he got called back before he got his boxes in the car. "Whoops! We didn't mean it! Turns out no one else in the universe knows how to do this!". Luckily, he was a canny old gent, and responded with a well-deserved, "Sure. I'll come back in. But it's gonna cost ya".
      - mechhacker 3y ago
        I saw bits and pieces of this interacting with DERs when I was working in the field, and you're touching on what I saw first hand. Thankfully I wasn't working on anything related to the MAX.
    - someweirdperson 3y ago
      I think regulations refering to a competent agency doesn't require any competency in the normal sense of the word. And perfectly good those planes were not, they had broken AoA sensors.
- jacobn 3y ago
  My understanding was that there was a design issue that was supposed to be fixed by software, and that software in turn had a bug.
- deleted 3y ago
  [deleted]
- axus 3y ago
  The design was not "backwards-compatible" with existing pilot training, but the plan was to use software as a cheap fix. They said pilots would not need new training, and were betting lives on the reliability of software and humans.
  - TheBigSalad 3y ago
    I don't see anything wrong with that aside from the buggy software.

When I found out about MAX and what happened with the design, after leaving that industry, I was amazed it had gotten approved. That number there indicates that.

TheBigSalad 3y ago

Wasn't the cause a software bug that was fixed and not a design issue?

rawgabbit 3y ago
It's not a bug. Boeing deliberately chose to mislead the airlines and pilots on what they were doing and used software to hide the fact. On top of that there was no redundancy for the single indicator which triggers the nose down/pitch down. The software issues is downstream of the managerial malfeasance.
JumpCrisscross 3y ago
It was a regulatory bottleneck prompting an inefficient design that required a software fix to fly, which relied mortally on the inputs from a sensor that was optionally non-redundant outside the United States.
- mechhacker 3y ago
  Yep. They were trying to compensate for different feel/behavior to the pilots without additional training. I really don't see how that was approved by a competent agency... Ended up in those two horrible crashes in perfectly good airplanes.
  - JumpCrisscross 3y ago
    > don't see how that was approved by a competent agency The version that flies in America has two AoA sensors. To my knowledge, those planes didn't have a problem.
    - wkat4242 3y ago
      Don't forget a lot of countries rely on the FAA for guidance because they don't all have the resources or manufacturer access to thoroughly evaluate an aircraft themselves. Also, even with two AoA sensors the pilot had to switch to the alternate because the MCAS wouldn't know which one was right. This is why usually 3 sensors are used in redundant systems.
  - MilStdJunkie 3y ago
    Because when you're a DER (Designated Engineering Representative), you're still getting your paycheck from Boeing, and being a fussy DER is not a fast track to success. I can't lay down too much more specifics, but anecdotally, that's how things go, and not just at Boeing either. Seen it at a lot of suppliers too. You're a "good" DER, or you're on the short list next round of layoffs[1]. DERs have been getting more and more sign off authority on increasingly critical core airworthiness systems, stuff no one would have dreamed of delegating to a DER twenty years ago. The actual full time agency people, well, depends on how much they're fishing for a corner office. But by and large, they were hardasses, thank God. All three of them. Particularly the EUROCAE Dutch guys. Whew! But none of this is important as the Boeing culture, which . . ehhhhhhyyyyuuuuuchhh . . could use some improvements. To phrase it one way. [1] There's always layoffs, good times and bad, because everything is funded contract to contract, week to week. I had a goddamn amazing analog engineer get pink slipped, packed his stuff, and then - after all that - he got called back before he got his boxes in the car. "Whoops! We didn't mean it! Turns out no one else in the universe knows how to do this!". Luckily, he was a canny old gent, and responded with a well-deserved, "Sure. I'll come back in. But it's gonna cost ya".
    - mechhacker 3y ago
      I saw bits and pieces of this interacting with DERs when I was working in the field, and you're touching on what I saw first hand. Thankfully I wasn't working on anything related to the MAX.
  - someweirdperson 3y ago
    I think regulations refering to a competent agency doesn't require any competency in the normal sense of the word. And perfectly good those planes were not, they had broken AoA sensors.
jacobn 3y ago
My understanding was that there was a design issue that was supposed to be fixed by software, and that software in turn had a bug.
deleted 3y ago
[deleted]
axus 3y ago
The design was not "backwards-compatible" with existing pilot training, but the plan was to use software as a cheap fix. They said pilots would not need new training, and were betting lives on the reliability of software and humans.
- TheBigSalad 3y ago
  I don't see anything wrong with that aside from the buggy software.