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Whilst this is an interesting read and is almost certainly largely true it does not entirely square with the fact that Boeing are working (and the FAA expect th

Whilst this is an interesting read and is almost certainly largely true it does not entirely square with the fact that Boeing are working (and the FAA expect the certify) a software fix by April - as noted in their press release. Software bugs or not - it does seem a major factor was the lack of an extra "AoA sensor" and a "sensor disagreement indicator". Presumably a very low cost option in reality that Boeing should have made standard fitment at least for the first year or so whilst they worked out any kinks in the MCAS system.

ncallaway 8y ago
The fact that Boeing is working on a software fix doesn't contradict the thread. It's explicitly mentioned in the thread. https://mobile.twitter.com/trevorsumner/status/1106934422249582593 https://mobile.twitter.com/trevorsumner/status/1106934422249... > Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid. (some related follow up tweets) > I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved. > But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid. > Follow @davekammeyer if you want to dig in.
- buchanan 8y ago
  I don’t get this thinking, if you’re in the bandaid making business, maybe make sure it doesn’t cause an infection ? In this case the software was developed to compensate for the system characteristic,it did not fully do that. Of course, it is immensely frustrating that software is always called upon to the papering up, but that is another issue.
  - ncallaway 8y ago
    Sure, I'm not necessarily endorsing the thread. I'm just saying the existence of an in progress software patch in no way contradicts the thread itself. It's part of the premise of the thread itself.
    - buchanan 8y ago
      I was looking at it from the narrow view that it was to do A (the papering over), and it did not do that (fully). On second thought, it’s more a systems engineering issue not to take that case into account. Software engineering doesn’t get off scot free though, as they are an important voice. With the presumably tight engineering controls that are practised, I can speculate that it may have fallen into “the pilot disables and takes over control” branch. The gap would then be that they did not think that the airlines would be given the option to “not” install the sensor failure warning.
tntn 8y ago
The software fix is probably further automation to disable the system when some other sensor indicates that it is misbehaving - i.e. it is probably a band aid on top of a band aid.
OJFord 8y ago
> Software bugs or not - it does seem a major factor was the lack of an extra "AoA sensor" and a "sensor disagreement indicator". Per the thread, they were sold as optional extras, but not sold in these cases.

ncallaway 8y ago

The fact that Boeing is working on a software fix doesn't contradict the thread. It's explicitly mentioned in the thread. https://mobile.twitter.com/trevorsumner/status/1106934422249582593 https://mobile.twitter.com/trevorsumner/status/1106934422249... > Nowhere in here is there a software problem. The computers & software performed their jobs according to spec without error. The specification was just shitty. Now the quickest way for Boeing to solve this mess is to call up the software guys to come up with another band-aid. (some related follow up tweets) > I'm a software engineer, and we're sometimes called on to fix the deficiencies of mechanical or aero or electrical engineering, because the metal has already been cut or the molds have already been made or the chip has already been fabed, and so that problem can't be solved. > But the software can always be pushed to the update server or reflashed. When the software band-aid comes off in a 500mph wind, it's tempting to just blame the band-aid. > Follow @davekammeyer if you want to dig in.

buchanan 8y ago
I don’t get this thinking, if you’re in the bandaid making business, maybe make sure it doesn’t cause an infection ? In this case the software was developed to compensate for the system characteristic,it did not fully do that. Of course, it is immensely frustrating that software is always called upon to the papering up, but that is another issue.
- ncallaway 8y ago
  Sure, I'm not necessarily endorsing the thread. I'm just saying the existence of an in progress software patch in no way contradicts the thread itself. It's part of the premise of the thread itself.
  - buchanan 8y ago
    I was looking at it from the narrow view that it was to do A (the papering over), and it did not do that (fully). On second thought, it’s more a systems engineering issue not to take that case into account. Software engineering doesn’t get off scot free though, as they are an important voice. With the presumably tight engineering controls that are practised, I can speculate that it may have fallen into “the pilot disables and takes over control” branch. The gap would then be that they did not think that the airlines would be given the option to “not” install the sensor failure warning.

tntn 8y ago

The software fix is probably further automation to disable the system when some other sensor indicates that it is misbehaving - i.e. it is probably a band aid on top of a band aid.

OJFord 8y ago

> Software bugs or not - it does seem a major factor was the lack of an extra "AoA sensor" and a "sensor disagreement indicator". Per the thread, they were sold as optional extras, but not sold in these cases.