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This makes no sense, we know that they increase the MCAS action range from 0.6° to 2.5° and they didn't inform FAA of the change. So, they must have told tests

by Glawen 7y ago

This makes no sense, we know that they increase the MCAS action range from 0.6° to 2.5° and they didn't inform FAA of the change. So, they must have told tests pilots about the feature, otherwise why did they change the parameters ?

heisenbit 7y ago
It may be that they kept this information in a small circle. MCAS was supposed to keep the plane flying similar so discussions of where this idealized model was breaking were kept quiet. It is still incredible. There was one big change in a high volume plane and that one big change should have been tested and tested again. Somehow Boeing started to believe their own cool aid. The more I think about the MAX the scarier it gets. What if one engine fails during start? The forward mounted other engine goes full throttle pulling up more than pilots are trained to handle.
- rbanffy 7y ago
  That's the kind of shenanigan that makes test pilots demand ejection seats...
- Glawen 7y ago
  You mean that the engineers quietly analyzed the test flight data and decided to increase the parameters on their own, so that the flight data show similarity between a MAX and a NG ? I find it so huge that it is hard to believe. Unless they took SW guys with no clue about how to do their jobs, like fresh graduate with no mentoring, or even outsourced to a SW shop ? I would never take responsability of such a change without even talking to the pilots about it. It is hundred timed worse than the VW engineers who cheated the homologation test.
  - Anarch157a 7y ago
    "Never attribute to malice what can be explained by incompetence". In VW's case, it's clear as day that it was malice and greed. In Boeings case, I was willing to write it down as incompetence at first, but as time goes by, I'm becoming more inclined to put it on the malice bin.
  - SallySwanSmith 7y ago
    Isn’t most/all of Boeing’s development done overseas now? I wonder if that divide makes it easier to assume this is okay.
  - xiphias2 7y ago
    VW has a much bigger silent impact of millions of people dying every year, while Boeing has probably less than 1000 people killed from this mistake. The danger of air pollution and global warming is that it's so hard to quantify the effects, but we already know that it's huge.
- Gravityloss 7y ago
  Moving the engine backwards or forwards along its thrust line does not cause changes in its moment around the plane's center of gravity. The pitchup is caused by aerodynamic forces on the engine at high angle of attack.
skywhopper 7y ago
It all goes back to the root cause: an impossible goal was thought to be so important to the company that reality had to bend to accommodate it. The impossible requirement was that the plane had to behave in such a way that pilots wouldn't need to know the correction system existed. If you work under that pressure for long enough, and enough of the engineers who realize it was BS move on, retire, etc, then as you approach the deadline, you rationalize and justify more and more. You've already embraced the idea that commercial pilots won't need to know about the existence this system that corrects the attitude of the plane, you've already rationalized leaving it out of the documentation and training and pretending it's not part of the control system. So why would test pilots need to know the parameters either? At the point they were at, this was a tiny leap to make.

by Glawen 7y ago

heisenbit 7y ago

It may be that they kept this information in a small circle. MCAS was supposed to keep the plane flying similar so discussions of where this idealized model was breaking were kept quiet. It is still incredible. There was one big change in a high volume plane and that one big change should have been tested and tested again. Somehow Boeing started to believe their own cool aid. The more I think about the MAX the scarier it gets. What if one engine fails during start? The forward mounted other engine goes full throttle pulling up more than pilots are trained to handle.

rbanffy 7y ago
That's the kind of shenanigan that makes test pilots demand ejection seats...
Glawen 7y ago
You mean that the engineers quietly analyzed the test flight data and decided to increase the parameters on their own, so that the flight data show similarity between a MAX and a NG ? I find it so huge that it is hard to believe. Unless they took SW guys with no clue about how to do their jobs, like fresh graduate with no mentoring, or even outsourced to a SW shop ? I would never take responsability of such a change without even talking to the pilots about it. It is hundred timed worse than the VW engineers who cheated the homologation test.
- Anarch157a 7y ago
  "Never attribute to malice what can be explained by incompetence". In VW's case, it's clear as day that it was malice and greed. In Boeings case, I was willing to write it down as incompetence at first, but as time goes by, I'm becoming more inclined to put it on the malice bin.
- SallySwanSmith 7y ago
  Isn’t most/all of Boeing’s development done overseas now? I wonder if that divide makes it easier to assume this is okay.
- xiphias2 7y ago
  VW has a much bigger silent impact of millions of people dying every year, while Boeing has probably less than 1000 people killed from this mistake. The danger of air pollution and global warming is that it's so hard to quantify the effects, but we already know that it's huge.
Gravityloss 7y ago
Moving the engine backwards or forwards along its thrust line does not cause changes in its moment around the plane's center of gravity. The pitchup is caused by aerodynamic forces on the engine at high angle of attack.

skywhopper 7y ago

It all goes back to the root cause: an impossible goal was thought to be so important to the company that reality had to bend to accommodate it. The impossible requirement was that the plane had to behave in such a way that pilots wouldn't need to know the correction system existed. If you work under that pressure for long enough, and enough of the engineers who realize it was BS move on, retire, etc, then as you approach the deadline, you rationalize and justify more and more. You've already embraced the idea that commercial pilots won't need to know about the existence this system that corrects the attitude of the plane, you've already rationalized leaving it out of the documentation and training and pretending it's not part of the control system. So why would test pilots need to know the parameters either? At the point they were at, this was a tiny leap to make.