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Boeing 737 MAX crash and the rejection of ridiculous data

philip.greenspun.com

11–20 of 194 posts

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#11

This video from "Mentour pilot" has been deleted (supposedly upon request from boeing): https://www.youtube.com/watch?v=EzgBft-79U8 You can see it here (european version of youtube): https://vimeo.com/329558134 Or more info here: https://news.ycombinator.com/item?id=19627525

It was not deleted on the request of boeing but because the creator did not feel okay about it. He addresses the issue here: https://www.youtube.com/watch?v=q17vykscK0w

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#12

Now, imagine you have 5,000 such checks in millions of lines of flight control system code, many of them interdependent, and you have to fly the ship to test each one. You need to schedule time with the test pilots (who have lives of their own) and get the data dump from IT post-flight. It's aerospace so all this undergoes review, documentation, and signoff, and it all takes time. How do you prevent a single check fr…

It's more an issue of Boeing essentially signing off on their own certification as functionally the same type when it is a very different plane.

The AOA calculation is also much more complicated than the article explains. There is a speed element, engine power, etc.

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#13

This video from "Mentour pilot" has been deleted (supposedly upon request from boeing): https://www.youtube.com/watch?v=EzgBft-79U8 You can see it here (european version of youtube): https://vimeo.com/329558134 Or more info here: https://news.ycombinator.com/item?id=19627525

It was not deleted on the request of boeing but because the creator did not feel okay about it. He addresses the issue here: https://www.youtube.com/watch?v=q17vykscK0w

https://www.pprune.org/rumours-news/619272-ethiopian-airline...

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#14
The sensor reading could have just as easily been 24 degrees rather than 70 and caused the same crash w/ the author's proposal.

Not saying or excusing the failures that led to this crash, but it seems like an oversimplification of the needed solution to suggest that ridiculous data be thrown out, with the benefit of hindsight being used to determine where the threshold of "ridiculous" is.

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#15
post #8

With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious". I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

Do you think the analysis is invalid?

Do you think that an autopilot response to "AOA > 15 degrees" should be the same regardless of whether AOA is 20, 40, 60, or 80 degrees?

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#16

This video from "Mentour pilot" has been deleted (supposedly upon request from boeing): https://www.youtube.com/watch?v=EzgBft-79U8 You can see it here (european version of youtube): https://vimeo.com/329558134 Or more info here: https://news.ycombinator.com/item?id=19627525

Vimeo is based in NYC USA, how is it "European version of YouTube"?

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#17
post #8

With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious". I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

philg's been flying and writing about it for years: https://philip.greenspun.com/flying/

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#18
post #8

With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious". I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

I agree that we frequently see this on HN in regards to aviation. However, I don;t think it applies to Greenspun. He's a knowledgeable and active pilot himself.

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#19
post #8

With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious". I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

Philip Greenspun is a highly experienced pilot:

https://philip.greenspun.com/flying/milestones

Re: Boeing 737 MAX crash and the rejection of ridiculous data

#20
post #8

With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious". I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

Philip Greenspun is, in fact a pilot. He is not a 737 pilot, but probably has a better idea of how a 737 works than the average HN armchair quarterback.
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