How Boeing, FAA certified the suspect 737 MAX flight control system • Hacker News Board

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#191

Post by dboreham » Tue, Mar 19, 2019, 2:49 PM UTC

jussij wrote: post #168

The details provided by the article read rather badly for Boeing for several reasons. Firstly, I think the whole issue is not going away any time soon which is bad enough. But what looks worse is the article points to high levels of incompetence, if not gross negligence in the design and testing of the MCAS. Like all 737s, the MAX actually has two of the sensors, one on each side of the fuselage near the cockpit. But…

I think the underlying problem is that a control system was designed with the assumption that its purpose was to make the pilot force feedback feel right, for regulatory compliance reasons. Therefore it was designed with low reliability requirements, presumably on the basis that if it doesn't work, no biggie because it's only there to make the controls feel right, and that only happens when the plane is about to stall, which never happens...

Then...it turned out that when this control system malfunctions (which is can, quite often, due to aforementioned low reliability requirements), it will actually crash the plane.

The lesson is probably: make sure that some system you're designing with low reliability characteristics (only uses one sensor, doesn't have redundant power supplies...) will fail with safe or benign outcomes.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#192

Post by ineedasername » Tue, Mar 19, 2019, 3:08 PM UTC

johnsea wrote: post #39

ineedasername wrote: post #33

Earlier quoted context omitted.

Hopefully it will also fall in part on the FAA, which greenlit the thing for use without checks that might have caught this.

And will it also fall in part on the passengers who demand cheap and cheaper air fares? (Not only to the detriment of their own safety but also to further increasing ecological debts).

Sure, it falls on the passengers in the form of increased risk and, in the case of crashes, actual death. Otherwise though, no it doesn't fall on them. They're not in the chain of responsibility for building and certifying planes as safe and free of defect.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#193

Post by dang » Tue, Mar 19, 2019, 5:53 PM UTC

bookofjoe wrote: post #189

dang wrote: post #79

Earlier quoted context omitted.

Ok, we've changed the URL to that article from https://qz.com/1574878/pilots-trained-for-boeing-737-max-wit... in keeping with the guidelines' call for original sources. Thanks!

I often submit original scientific articles and reports here that achieve no traction. When I then submit less technical versions appearing in more mainstream media — New York Times, Wired, Verge, The New Yorker, etc. — they frequently appear on the home page, generating hundreds of comments. I'm always in a quandary as to which approach to take: after all, if a tree falls in a forest....

Yes, that's a common pattern. Experience has taught us that it's best to submit the highest-quality popular article on a topic and link to the original paper in the thread. If an article is too specialist-oriented it probably won't do well here regardless of how interesting it is. Papers on computing are an exception, because a significant subset of the audience here is able to read those.

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#194

Post by netsharc » Tue, Mar 19, 2019, 7:00 PM UTC

johnsea wrote: post #39

ineedasername wrote: post #33

Earlier quoted context omitted.

Hopefully it will also fall in part on the FAA, which greenlit the thing for use without checks that might have caught this.

And will it also fall in part on the passengers who demand cheap and cheaper air fares? (Not only to the detriment of their own safety but also to further increasing ecological debts).

Come on, way to blame the victim. Of course we all want cheaper things, but everyone got on those 2 planes with the faith that it would take-off and land safely, it's not like they signed a disclaimer saying "I accept the risk of death to the fact that the plane is an unairworthy rust bucket but I deemed it OK because the airfare was cheap.".

Re: How Boeing, FAA certified the suspect 737 MAX flight control system

#195

Post by bookofjoe » Tue, Mar 19, 2019, 7:25 PM UTC

dang wrote: post #193

bookofjoe wrote: post #189

Earlier quoted context omitted.

I often submit original scientific articles and reports here that achieve no traction. When I then submit less technical versions appearing in more mainstream media — New York Times, Wired, Verge, The New Yorker, etc. — they frequently appear on the home page, generating hundreds of comments. I'm always in a quandary as to which approach to take: after all, if a tree falls in a forest....

Yes, that's a common pattern. Experience has taught us that it's best to submit the highest-quality popular article on a topic and link to the original paper in the thread. If an article is too specialist-oriented it probably won't do well here regardless of how interesting it is. Papers on computing are an exception, because a significant subset of the audience here is able to read those.

Thank you for this advice. I will follow it.