Singapore temporarily suspends Boeing 737 Max into and out of its airports

oof. It would be nice if there were some clarity on what happened on those flights - even if it's only for the families who lost people. That said it would be nice to know what is going that has resulted in such an (apparently) above mean crash rate.

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#5

Post by samcheng » Tue, Mar 12, 2019, 5:11 AM UTC

It's ironic that it's a Boeing with bad software (or sensors) interfering between yoke and plane. After all, historically, Boeing has had the philosophy of trusting the pilot with direct control of the plane. This is in comparison with Airbus, where controls are by stick instead of yoke, and pilots are taught to trust the flight computer and move the controls less. (Of course, these days both manufacturers build fly-by-wire planes.) [1]

The addition of a 'maneuvering characteristics augmentation system' seems very unlike Boeing. I guess it became necessary after adding too-big engines without otherwise adjusting the airframe... [2]

This "we'll fix it with software later" attitude works well with CPU errata and maybe Teslas, but it doesn't look like we're there yet for airplanes, unfortunately.

[1] https://www.pprune.org/tech-log/10321-stick-vs-yoke-airbus-v...

[2] https://theaircurrent.com/aviation-safety/what-is-the-boeing...

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#6

Post by taneq » Tue, Mar 12, 2019, 5:14 AM UTC

djsumdog wrote: post #3

There's another thread on here about this article that discusses one potential issue that's being looked at: https://theaircurrent.com/aviation-safety/what-is-the-boeing... https://news.ycombinator.com/item?id=19365179

My interpretation of that first link: The new engines meant the plane would stall easier under some circumstances so rather than telling everyone about it, they bandaided this behaviour by adding pitch-down based on the measured angle of attack. However, if the single angle-of-attack sensor fails the plane can suddenly dive.

Sounds like planes need an "automation e-stop", some kind of quick standardized way to return a plane to full manual control.

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#7

Post by sk5t » Tue, Mar 12, 2019, 5:19 AM UTC

samcheng wrote: post #5

It's ironic that it's a Boeing with bad software (or sensors) interfering between yoke and plane. After all, historically, Boeing has had the philosophy of trusting the pilot with direct control of the plane. This is in comparison with Airbus, where controls are by stick instead of yoke, and pilots are taught to trust the flight computer and move the controls less. (Of course, these days both manufacturers build fly-…

Ditto, it was my impression that direct control / mechanical linkage was the underpinning for the "if it's not Boeing I'm not going" mindset.

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#8

Post by chx » Tue, Mar 12, 2019, 5:20 AM UTC

This is very significant. Singapore has https://www.faa.gov/news/press_releases/news_story.cfm?newsI... a bilateral agreement with the FAA which "provides for the mutual recognition of airworthiness of civil aeronautical products" (Reuters reported China wants this but couldn't achieve it yet). Now, the SG CAAS did not yet issue a declaration on the airworthiness of the 737 Max 8 but this puts immense pressure on the FAA-EASA-TCAA-etc family to move.

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#9

Post by topspin » Tue, Mar 12, 2019, 5:22 AM UTC

Multiple eye witness reports have the 737 trailing smoke and debris and making unusual sounds before impact [1]. That's not the sort of report one would expect if an otherwise intact aircraft flew into terrain due to some flaw with MCAS.

[1] https://www.reuters.com/article/us-ethiopia-airplane-witness...

Re: Singapore temporarily suspends Boeing 737 Max into and out of its airports

#10

Post by tedunangst » Tue, Mar 12, 2019, 5:23 AM UTC

chx wrote: post #8

This is very significant . Singapore has https://www.faa.gov/news/press_releases/news_story.cfm?newsI... a bilateral agreement with the FAA which "provides for the mutual recognition of airworthiness of civil aeronautical products" (Reuters reported China wants this but couldn't achieve it yet). Now, the SG CAAS did not yet issue a declaration on the airworthiness of the 737 Max 8 but this puts immense pressure on th…

Is the bilateral agreement AND or OR?