OT: Deadly 'Misguided Assumptions' Were Built Into Boeing's 737 Max

On Monday, June 3, 2019 at 5:15:18 PM UTC-4, Lasse Langwadt Christensen wro te:

And what does a stick pusher do? Why is that an anti-stall system and MCAS is not? Here from a simple search of "MCAS anti stall":

A pilot explains the Boeing 737 Max's anti-stall system - BBC News

ll-system Captain Chris Brady has flown the Boeing 737 for 18 years. He told the BBC' s Transport correspondent Tom Burridge about the anti-stall system used by the ... Boeing anti-stall system was activated in Ethiopia crash: source

? Technology ? Other Mar 29, 2019 - Boeing's MCAS anti-stall system, which was implicated in the October crash of a 737 MAX 8 airliner in Indonesia, was also activated sho rtly before a recent accident in Ethiopia, a source with knowledge of the i nvestigation said Friday. ... The information retrieved from the plane's .. .

737 Max 8 Anti-Stall System Reactivated After Being Manually ...

? Extreme Apr 3, 2019 - After the Lion Air 610 disaster last year, we learned the Boe ing 737 Max 8 was equipped with a new system designed to automatically prev ent stalls under certain conditions. ... Were they aware that deactivating the MCAS (Maneuvering Characteristics Augmentation System) would allow ... Ethiopian Air pilots turned off 737 MAX anti-stall system. Then it turned . ..

all-system-th... Apr 3, 2019 - Ethiopian Air pilots turned off 737 MAX anti-stall system. .. . notice following the Lion Air crash noted that the MCAS' automated adjust ments to a ... People also ask

-ethiopia-cras... Mar 31, 2019 - October's Ethiopian crash of a 737 MAX 8 in Indonesia had th e MCAS anti-stall system activated shortly before a recent accident in Ethi opia. Ethiopian crash: Boeing 737 Max anti-stall system likely activated? WSJ

ikely-acti... Mar 29, 2019 - Based on data retrieved from the flight's black boxes, the s tall prevention system ? also known as the MCAS ? activated automatically before ... Boeing 737 Max 8 crash: Anti-stall system activated on Ethiopian plane

002/ Mar 29, 2019 - Investigators believe Boeing anti-stall system was activated in ..... same automated system, called MCAS, that occurred just prior to t he crash of ... Anti-Stall System Switched on Before Ethiopian Airlines 737 MAX ...

time.com ? Business ? Aviation Mar 29, 2019 Anti-Stall System Switched on Before Ethiopian Airlines Boeing 737 .... to MCAS within weeks of the Lion ... Anti-stall system was 'in play' on Ethiopian's Boeing 737 Max | World ...

-boeing-737... Mar 25, 2019 - MCAS feature also highlighted by investigation into earlier crash of Lion Air plane. Black box data shows anti-stalling feature was engaged in Ethiopia ...

ed346f0e... Mar 29, 2019 - MCAS was a factor in earlier Lion Air crash. ... scouring bl ack box data believe an automatic anti-stalling feature was engaged before a Boeing ...

Boeing fix will prevent repeated activation of anti-stall system: sources . ..

anti-stall-sy... Mar 25, 2019 - The anti-stall system - known as MCAS, or Maneuvering Charac teristics Augmentation System - has been pinpointed by investigators probin g ... Black box data shows anti-stalling feature was engaged in Ethiopia ...

ed346f0e... Mar 29, 2019 - MCAS was a factor in earlier Lion Air crash. ... scouring bl ack box data believe an automatic anti-stalling feature was engaged before a Boeing ... Boeing says software fix will always allow override of anti-stall system .. .

llow-over... Apr 4, 2019 - Boeing ([[BA]] +2.4%) says a new software fix for its anti-st all system will give ... Flight crews will always have the ability to overr ide MCAS and ... Ethiopian Airlines crash: Automatic anti-stall system activated ...

ndex.html Apr 2, 2019 - Preliminary findings from officials investigating the Ethiopi an Airlines Boeing 737 MAX 8 crash suggest that a flight-control feature au tomatically ... Changes to Flight Software on 737 Max Escaped F.A.A. Scrutiny - The ...

Apr 11, 2019 - MCAS was created to help make the 737 Max handle like its .. . Because the changes to the anti-stall system affected how it operated at lower ... What went wrong with the Boeing 737 Max 8 ? Quartz

Mar 18, 2019 - ... to how an automated anti-stalling system may be linked t o the model's ... The new design increased the risk that the plane could st all if pilots angled the ... But every time a pilot straightens the plane o ut, the MCAS resets. Anti-stall system was activated before Ethiopian Airlines Boeing 737 ...

nes.../story?... Mar 29, 2019 - Sources told ABC News that a preliminary report, which will include these findings on the Boeing 737 MAX MCAS system, is expected to be ... Boeing CEO explains why 737 Max pilots were not told of MCAS ...

of-mc... Apr 29, 2019 - The existence of MCAS came to light only after the crash of Lion Air Flight ... the media's characterization of MCAS as an anti-stall s ystem. WSJ: Anti-stall system activated in Ethiopian Boeing crash | Ethiopia ...

ing-crash-1... Mar 29, 2019 - Wall Street Journal reports investigators' initial finding i s MCAS automatically turned on before Ethiopia plane crash.

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e every four and a half years. In May 1990, six years before TWA 800, a cen ter tank exploded on a Philippine Airlines 737 shortly before take off, kil ling eight people. Four years and eight months after TWA 800, the center ta nk of a Thai Airways jet exploded on the ground, killing one person."

money on their in-flight entertainment system than a fuel tank oxygen remov al system could ever cost.

their interpretation is pathetically naive.

37 MAX. They in fact handed the entire certification off to Boeing with the certification reports being "reviewed" by semi-comatose swivel chair opera tors with probably less than 10% (on the high end) comprehension of what th ey were reading. And when NYT reports Boeing delivered this or that informa tion to FAA, it only means it was part of a probably huge documentation pac kage most of which was simply glossed over by the FAA. As is typical of mos t politicized bureaucracies, they're just not going to pay much attention t o anything that's not already a high visibility issue.

tastrophic failure mechanism because the pilot is always available to pull the system out of MCAS control, and the MCAS was relatively slow acting, ta king 10 seconds to do anything. And you can't implement a voting scheme wit h just two sensors. The only good a second sensor would serve is if it was something the pilot could switch in when/if the first sensor gave him troub le with the MCAS.

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flight characteristics as "too rough" for passenger comfort. So they modified the original MCAS to the current form. The original MCAS i ncluded a g-threshold in addition to attack angle. I think that one had to do with surviving turbulence like microbursts.

BS. MCAS is involved at the point the AOA is so high the plane is close to stalling. It had nothing to do with passenger comfort in normal flight. Show us the cites for what you claim.

yeh, mainstream media journalist are a great source of information on something technical /s

I think I will put a bit more weight on what people certified to fly the thing says

From the very first link:

"A pilot explains the Boeing 737 Max's anti-stall system

Captain Chris Brady has flown the Boeing 737 for 18 years. He told the BBC's Transport correspondent Tom Burridge about the anti-stall system used by the Max model. "

he doesn't say it is an anti stall system, he is showing the stick shaker in a 737 NG and the journalist have added some text to some Boeing video saying it is anti stall

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cteristic. I haven't read anywhere that the new engines would cause the pl ane to stall.

I think we are saying the same thing except you refer to "approaching a sta ll". I can't find a reference that says this. They all say if "the nose i s too high" it will push it back down again. I don't see any that refer to "approaching a stall". The two statements are not the same.

I don't see any need for the system to try to only manipulate the controls as the plane is "approaching a stall". The pilots can do that. It's actua lly part of their jobs to monitor the various attitudes of the plane and ma nage the controls to keep the plane in appropriate trim.

I don't see a reference for this now, but I have seen articles that indicat e the purpose of MCAS is to manage the tendency of the nose to rise in some situations so the pilots don't need to be aware of this tendency and corre ct it before it becomes a problem.

Maybe we are saying the same thing with a different emphasis.

--

  Rick C. 

  +- Get 1,000 miles of free Supercharging 
  +- Tesla referral code - https://ts.la/richard11209

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C's Transport correspondent Tom Burridge about the anti-stall system used b y the Max model. "

Do you understand that the term "anti-stall" is from the author of the arti cle and not necessarily from Tom Burridge? Burridge is not being quoted th ere. All of your citations (most, I gave up looking at the last few) are t he same way with the use of that term coming from the author and not any qu oted source, such as Boeing.

It's not uncommon for a journalist to get something wrong and many others t o follow him and also get it wrong. In this case it is very tempting since "anti-stall system" is a lot easier to understand and get across to the re aders than an explanation of the actual function and purpose of the system.

A friend of mine is an expert on the human response to cold weather conditi ons and was running a non-profit some years ago. Air Florida 90 crashed an d he had just sent out a press release a couple of days before. A few jour nalists made the connection and called him to ask about the crash survivors who perished in the icy waters. One of them ended up referring to him as Dr. Avery even though my friend never said he was a doctor. Many others wh o never even contacted him picked that up and also reported what Dr. Avery said.

I expect that is what has happened here.

--

  Rick C. 

  ++ Get 1,000 miles of free Supercharging 
  ++ Tesla referral code - https://ts.la/richard11209

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s as the plane is "approaching a stall". The pilots can do that.

If they follow their training and act correctly, quickly. But we've had crashes though where the pilots kept pulling back on the controls, as the plane stalled and plummeted to earth, crashing.

It's actually part of their jobs to monitor the various attitudes of the plane and manage the controls to keep the plane in appropriate trim.

ate the purpose of MCAS is to manage the tendency of the nose to rise in so me situations so the pilots don't need to be aware of this tendency and cor rect it before it becomes a problem.

Yes, I mostly agree. I did see where Boeing denies that MCAS is an anti- stall system. But then they have a big reason to try to minimize what MCAS is and saying it's an anti-stall system as opposed to a "maneuvering characteristics augmentation system", could have implications for maintaining the type rating, training required and how much notice is given this whole thing buy the FAA, those buying the planes, etc.

What is clear is that the Max has an issue where the nose will rise easier compared to where it does with existing 737s. Part of getting it certified , they have to show that if the plane is flying normally and something perturbs it, that it doesn't then get into a positive feedback situation, where the plane then goes further in the wrong direction on it's own. If the AOA gets pushed up, the Max, unlike other 737s, the nose will then rise more, increasing the AOA further, because of the lift effect of the new engines. So MCAS was put in to counter that. It's only a concern at high angles of attack and if it were not countered, then a stall would occur when it got high enough. How much stall margin there is between where MCAS activates and a stall would occur, IDK. So, I would say MCAS is a system to mute the nose up problem at high AOA and by doing that, also a stall avoidance system.

What's clear is that it's not what some others have suggested here, ie for passenger comfort, a smooth ride, to maintain a landing approach, etc.

I see Boeing's troubles got worse, now they say there was a problem with defective slat rails being installed on the Max and other planes, requiring immediate inspections. IDK how that CEO is still there, IMO he needs to go.

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ols as the plane is "approaching a stall". The pilots can do that.

Now that's confusing. You keep saying the MCAS is to prevent stalls, are y ou now saying it causes the plane to stall? This is very confusing...

So the MCAS stepped in appropriately when the plane starts to stall? So wh at goes wrong???

e plane and manage the controls to keep the plane in appropriate trim.

Bingo! But this plane handles differently than the previous versions of th e 737 so the MCAS was added to automatically compensate for the up pitch th is plane has making it "feel" like the other versions. The point was to no t require more training.

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I've never heard it expressed this way. I think your wording is poor that the engines cause the nose to "rise more". You make it sound like positive feedback. I think it is more like the handling of a car in a turn. Some cars oversteer, some understeer, some are pretty neutral. It's not that wh en you turn the car then "turns more" like a follow on effect.

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Ok, whatever.

--

  Rick C. 

  --- Get 1,000 miles of free Supercharging 
  --- Tesla referral code - https://ts.la/richard11209

The comments to the article are also interesting.

From what I have seen in the engineering press, there

*is indeed* a positive feedback effect. Such positive feedback effects are designed out of general aviation aircraft (not military) and the other 737s in particular.

In order to preserve the *illusion* that the positive feedback effect doesn't exist, MCAS gets between the pilots and the control surfaces in a way that wasn't explained to the pilots.

Analogies are dangerous, but if you want one then MCAS is like inserting a minimum speed setting and not telling the driver that the car will continue at a minimum speed unless they change gear.

Not relevant; all aircraft and manufacturers have such infelicities. What matters is how they are detected and dealt with.

On Tuesday, June 4, 2019 at 9:54:08 AM UTC-4, Rick C wrote: >

trols as the plane is "approaching a stall". The pilots can do that.

you now saying it causes the plane to stall? This is very confusing...

I wasn't talking about MCAS or just 737s there. You said that pilots can deal with stalls, that they don't need an anti-stall system. I was simply pointing out that there have been other plane crashes where the pilots obviously could not deal with a stall, including ones where the pilots were continuing to pull back on the controls with the plane stalled and plummeting to earth.

what goes wrong???

the plane and manage the controls to keep the plane in appropriate trim.

the 737 so the MCAS was added to automatically compensate for the up pitch this plane has making it "feel" like the other versions. The point was to not require more training.

ndicate the purpose of MCAS is to manage the tendency of the nose to rise i n some situations so the pilots don't need to be aware of this tendency and correct it before it becomes a problem.

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t the engines cause the nose to "rise more". You make it sound like positi ve feedback.

It is exactly that. The larger nacelles, located more forward, come into play at higher AOA and they cause additional lift that pushes the nose up more, an effect that doesn't exist in other 737s. It's an issue of handling and putting the airplane closer to a stall. It's also probably questionable if the plane could be certified without that behavior being fixed. If the plane is subject to something that perturbs it, it's supposed to stay put there or move back toward normal, not have feedback that instead moves it further in the perturbed direction.

I think it is more like the handling of a car in a turn. Some cars overst eer, some understeer, some are pretty neutral. It's not that when you turn the car then "turns more" like a follow on effect.

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Heck, no! This CEO (and his people) FOUND the problem, before failures in the field, and took the (benign) step of advising inspections. The supplier of those parts, on the other hand, presumably has not complied with the contractual requirements, and possibly is in trouble.

Your attempt to 'correct' the whistleblower would let the instigator off scot-free. Don't do that!

I didn't mean to imply that the CEO should go for the slat rails problem. I meant he should go for the MCAS fiasco, both that it came out of Boeing to begin with, to not informing operators in 2017 that the AOA disagree lights they paid for were inoperative, to totally mishandling it from the first crash on. The new rail problem just adds to their troubles at the worst possible time. It's not going to help convince people to fly on the Max again, that's for sure. What really went on with the rails and probably everything else at Boeing needs a good, hard look.

I watched Nora O'Donnell interview the CEO and things she never asked him was how this could have happened at Boeing, on his watch. Have they done an internal investigation, to find out how this went wrong? Have they looked at other programs at Boeing, put in place new procedures to make sure similar isn't affecting other aircraft?

And another interesting article. There are many statements therein; who knows the extent of the "truth" in it.

Snippets below...

The Max software -- plagued by issues that could keep the planes grounded months longer after U.S. regulators this week revealed a new flaw -- was developed at a time Boeing was laying off experienced engineers and pressing suppliers to cut costs.

Increasingly, the iconic American planemaker and its subcontractors have relied on temporary workers making as little as $9 an hour to develop and test software, often from countries lacking a deep background in aerospace -- notably India.

In one post, an HCL employee summarized his duties with a reference to the now-infamous model, which started flight tests in January 2016: ?Provided quick workaround to resolve production issue which resulted in not delaying flight test of 737-Max (delay in each flight test will cost very big amount for Boeing).

Boeing said the company did not rely on engineers from HCL and Cyient for the Maneuvering Characteristics Augmentation System, which has been linked to the Lion Air crash last October and the Ethiopian Airlines disaster in March. The Chicago-based planemaker also said it didn?t rely on either firm for another software issue disclosed after the crashes: a cockpit warning light that wasn?t working for most buyers.

(I wonder whether "rely" is a significant weasel word)

?Boeing was doing all kinds of things, everything you can imagine, to reduce cost, including moving work from Puget Sound, because we?d become very expensive here,? said Rick Ludtke, a former Boeing flight controls engineer laid off in

2017. ?All that?s very understandable if you think of it from a business perspective. Slowly over time it appears that?s eroded the ability for Puget Sound designers to design.?

Rabin, the former software engineer, recalled one manager saying at an all-hands meeting that Boeing didn?t need senior engineers because its products were mature. ?I was shocked that in a room full of a couple hundred mostly senior engineers we were being told that we weren?t needed,? said Rabin, who was laid off in 2015.

Boeing has also expanded a design center in Moscow. At a meeting with a chief

787 engineer in 2008, one staffer complained about sending drawings back to a team in Russia 18 times before they understood that the smoke detectors needed to be connected to the electrical system, said Cynthia Cole, a former Boeing engineer who headed the engineers? union from 2006 to 2010.