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Rudder issue that plagued the Boeing 737 throughout the 1990s

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Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#351

Post by marcosdumay »

lmm wrote: post #346
marcosdumay wrote: post #274

Earlier quoted context omitted.

A few years ago I calculated with a friend the accident rate of several cohorts of Brazilian aviation (well, the part of aviation that operates on aerodromes, so no agriculture or sports). Our worst cohort was for private planes, private pilots, on small airports, on fast growing cities. It was just a little bit under 4*10^-6 accidents (all, not only fatal) per airport operation (that is, twice your number). I was re…

Do those people jump into cars?

For long distance trips where they have an option? I'd guess that many don't.

Still that 4e-6 per trip number is worse than the city driving statistics I've found. And that 8e-6 per trip (4 per airport operation) is around the motorcycle values.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#352

Post by Kavenerinds »

hopler wrote: post #246
Kavenerinds wrote: post #240

Earlier quoted context omitted.

The industry/NTSB/FAA generally cares more about flight hours, but I agree with you. Both of these accidents happened shortly after takeoff. I am surprised that no accident has happened during landing.

Is the same sensor used the same way in landing?

I would imagine so. As long as the pilot wants to control the rudder, that same sensor would be used. What I would like to know is if the MAX has a different setup. I think it'd be idiotic of Boeing to use the same rudder control configuration as the old 737 considering the problems that they had as demonstrated by this post.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#353

Post by Retric »

stcredzero wrote: post #231
Retric wrote: post #193

Earlier quoted context omitted.

Over 32,000 journalists are working full time in the US, social media focus on a minute fraction of them. Social media can be a near full time job. One many successful people simply don’t have time for. So sure many NYT reporters might post their wedding photos online, but deeper interactions are often limited to people focusing on such things.

Over 32,000 journalists are working full time in the US, social media focus on a minute fraction of them. You're conflating two entirely different things here. Much of the dysfunction/groupthink occurs through things like legacy media journalists using social media. The point is that networks and social media enables offline channels for groupthink, which then affects other media. https://www.youtube.com/watch?v=AA2J…

> “some correspondents” never left bars in Saigon

My point is group think requires significant interaction over social media. This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threashold is not very common.

So, sure a small fraction are significantly influenced but the majority is not. Making the overall influence far less significant than it might appear.

On top of that mainstream news organizations like FOX, CNN, NPR differentiate based on appealing to different groups. Which creates different spheres of social media for each segment. This has been intensified with online sources the Drudge Report going mainstream and gathering vast followings. Which means social media is pulling different reporters in different directions.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#354

Post by stcredzero »

Retric wrote: post #353
stcredzero wrote: post #231

Earlier quoted context omitted.

Over 32,000 journalists are working full time in the US, social media focus on a minute fraction of them. You're conflating two entirely different things here. Much of the dysfunction/groupthink occurs through things like legacy media journalists using social media. The point is that networks and social media enables offline channels for groupthink, which then affects other media. https://www.youtube.com/watch?v=AA2J…

> “some correspondents” never left bars in Saigon My point is group think requires significant interaction over social media. This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threashold is not very common. So, sure a small fraction are significantly influenced but the majority is not. Making the overall influence far less significan…

My point is group think requires significant interaction over social media.

Then the behavior of many journalists over social media should greatly concern you.

This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threshold is not very common.

This is common among journalists. Particularly those working in niche media.

Making the overall influence far less significant than it might appear.

Those who know the facts behind certain niche stories are amazed at the degree of reality warping done by the mainstream media. Just look at what happened around the Covington kids.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#355

Post by southern_cross »

New information (to me anyway) and I didn't see it mentioned here yet. Apparently the MCAS was put into place to begin with in order to deal with a potential "imbalance" situation created by attaching new, bigger engines to an old airframe design.

"The new 737, named as the 737 MAX, would require -as usually- bigger engines, to offer an increased fuel efficiency, competitive to the one of the A320neo. And again, there was no room for them. So, the solution was to extend the front landing gear by eight inches and at the same time to move the LEAP-1B engines even more forward and higher up (image 3). This last design modification was later found to create an upward pitching moment during flight, which could bring the aircraft closer to stall under specific operating conditions. To tackle this problem, Boeing introduced the so-called Maneuvering Characteristics Augmentation System (MCAS). The MACS simply trims the stabilizer nose down, to counterbalance the moment created by the new engine positions."

https://www.linkedin.com/pulse/case-737-max-old-design-moder...

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#356

Post by pfdietz »

skookumchuck wrote: post #325
cco wrote: post #212

Earlier quoted context omitted.

In my experience end users are very often wrong, QA departments are rarely wrong. If pilots are saying I pressed the rudder and it didn't move healthy skepticism may be needed, I'd hazard less skepticism than for an average end user as the pilots are presumably highly skilled users of the product. But if after very thorough investigations a large group of pilot reports and the NTSB are telling you something is wrong…

The cases of "surging" where people claimed they were pressing hard on the brake when the car lept forward come to mind. (The most credible explanation is they put their foot on the gas instead, or are simply trying deflect blame away from themselves for the crash.)

That's not the most credible explanation.

http://users.ece.cmu.edu/~koopman/pubs/koopman14_toyota_ua_s...

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#357

Post by Retric »

stcredzero wrote: post #354
Retric wrote: post #353

Earlier quoted context omitted.

> “some correspondents” never left bars in Saigon My point is group think requires significant interaction over social media. This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threashold is not very common. So, sure a small fraction are significantly influenced but the majority is not. Making the overall influence far less significan…

My point is group think requires significant interaction over social media. Then the behavior of many journalists over social media should greatly concern you. This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threshold is not very common. This is common among journalists. Particularly those working in niche media. Making the overall…

The Covington Kids story shows how social media amplified both sides of an issue. It’s the opposite of group think with multiple narratives showing up.

What you’re describing “group consensus” is a systemic bias. A historical example of say US WWII propaganda qualifies as essentially all US news is shifted in the same direction.

Waves of news with story X being updated to story Y over time is a different thing. That’s a question of which organizations get involved over time. You can find examples that support any narrative based on timing. But, bias would mean the story did not evolve.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#358

Post by stcredzero »

Retric wrote: post #357
stcredzero wrote: post #354

Earlier quoted context omitted.

My point is group think requires significant interaction over social media. Then the behavior of many journalists over social media should greatly concern you. This requires more than visiting a bar one a month / posting wedding photos. It requires significant amounts of time and crossing that threshold is not very common. This is common among journalists. Particularly those working in niche media. Making the overall…

The Covington Kids story shows how social media amplified both sides of an issue. It’s the opposite of group think with multiple narratives showing up. What you’re describing “group consensus” is a systemic bias. A historical example of say US WWII propaganda qualifies as essentially all US news is shifted in the same direction. Waves of news with story X being updated to story Y over time is a different thing. That’…

The Covington Kids story shows how social media amplified both sides of an issue.

The behavior of mainstream journalists calling for the doxxing of and violence against these kids just strikes me as amazing. The groupthink involved with accepting the initial narrative is quite apparent.

What you’re describing “group consensus” is a systemic bias.

When systematic bias reaches the point where journalists completely abandon fact-checking and basic adult judgement, it's more than just "group consensus." Offering sexual favors to do things against kids? I'm sorry, but if I made something like that up, it would be purple prose. Journalists were swept up in that kind of groupthink!

A historical example of say US WWII propaganda qualifies as essentially all US news is shifted in the same direction.

Read Manufacturing Consent -- it's the same in 2019 as it was in the 1980's, we in the west just do it faster and harder with the bias, emotional words only for one side, and selective coverage. The thesis was that the west is just as bad as Pravda. In 2019, I find that Pravda was more subtle about it.

bias would mean the story did not evolve.

Bias can also mean that the retractions were either absent or all but meant to be invisible. In 2019, the typical media modus operandi is to technically be about the truth and retract, but engineer this to have basically zero effect. The number of mainstream sites who will edit a story, but give no indication of that, is just amazing to me.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#359

Post by Dylan16807 »

cdolan wrote: post #348
Dylan16807 wrote: post #340

Earlier quoted context omitted.

> The top comment on this thread (re: "acceptable loss"), is infuriating. Do you ever drive a car? Do you think the risk is "acceptable"? And don't get hung up on semantics, "acceptable" doesn't mean it's not terrible, it means that it's not feasible to prevent every risk with that danger:cost ratio. Especially because anything that causes a drastic reduction in flight will increase car trips and probably cause more…

Get out from behind your computer and talk to people for once.

It's easy to explain to people in the real world how treating life as having infinite value is actually impossible, and nobody actually does it.

Also, the "acceptable" part is the statistical average. It's still a tragedy that any particular person dies. I do have sympathy for you and your wife, but we have millions of deaths per year that deserve equal respect, and we only have so much we can do to prevent each one. We should try very hard, but we can't try infinitely hard.

Re: Rudder issue that plagued the Boeing 737 throughout the 1990s

#360

Post by skookumchuck »

pfdietz wrote: post #356
skookumchuck wrote: post #325

Earlier quoted context omitted.

The cases of "surging" where people claimed they were pressing hard on the brake when the car lept forward come to mind. (The most credible explanation is they put their foot on the gas instead, or are simply trying deflect blame away from themselves for the crash.)

That's not the most credible explanation. http://users.ece.cmu.edu/~koopman/pubs/koopman14_toyota_ua_s...

I don't buy it. Heck, I've even stepped on the gas instead of the brake. Besides, the brakes are much more effective than that little Toyota engine is. Try it yourself. Go full throttle and step hard on the brake. You'll stop.
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