Ed 737 Max Crashes (was Shutdown caused Boeing crash.)

[banquetbear]

Oh good. Maybe now you can go to bed and sleep peacefully.

...its only 5 in the afternoon. Not planning on going to sleep for a long time yet.

And concession accepted.

 

[Oystein]

Oh good. Maybe now you can go to bed and sleep peacefully.

The good form verbiage, best practice in this forum would have read: "I stand corrected. Thanks for your efforts."

 

[Skeptic Ginger]

The good form verbiage, best practice in this forum would have read: "I stand corrected. Thanks for your efforts."

If quad's initial reply to my post didn't come across as snarky, ('we already know that') then maybe banquetbear wouldn't have missed that quad and I resolved the issue (at least I thought we did) and then maybe banquetbear wouldn't have continued the snark with more 'we already know that'... then I suspect this whole discussion would have been...how should I put it.... a normal discussion of a non-controversial topic!
Why was this necessary:

...but the news media didn't miss anything. You missed it. It isn't particularly revelatory that you happened to miss something.

The issue was resolved. There was no reason for this followed by a dozen unnecessary exchanges.


Why are so many people in this forum so determined to make everything about concessions rather than discussions.

Discussion:

I didn't think the news media was covering X
Yes, they did, see here.
Those are not mainstream news sites.
OK, here is a MSM source.
Hmm, still not seeing Y.
Here's a link to Y.
Great.​

End of non-controversial, not a pissing contest discussion.


If banquetbear wants to apologize for starting off with needless snark, I will thank them for the links.

 

[banquetbear]

If quad's initial reply to my post didn't come across as snarky, ('we already know that') then maybe banquetbear wouldn't have missed that quad and I resolved the issue (at least I thought we did) and then maybe banquetbear wouldn't have continued the snark with more 'we already know that'... then I suspect this whole discussion would have been...how should I put it.... a normal discussion of a non-controversial topic!
Why was this necessary:The issue was resolved. There was no reason for this followed by a dozen unnecessary exchanges.


Why are so many people in this forum so determined to make everything about concessions rather than discussions.

Discussion:

I didn't think the news media was covering X
Yes, they did, see here.
Those are not mainstream news sites.
OK, here is a MSM source.
Hmm, still not seeing Y.
Here's a link to Y.
Great.​

End of non-controversial, not a pissing contest discussion.


If banquetbear wants to apologize for starting off with needless snark, I will thank them for the links.

...wow.

You just can't let anything go, can you?

Oh well. Maybe now you've got that off your chest you can go to bed and sleep peacefully.

 

[smartcooky]

Looks like the whistle has been blown on some very dodgy practices with the Boeing 747 MAX

"On Apr 27th 2019 it became known, that four independent whistleblowers, current and former Boeing employees, had called the FAA hotline for whistleblowers regarding aviation safety concerns on Apr 5th 2019. The concerns reported were wiring damage to the AoA related wiring as result of foreign object damage as well as concerns with the TRIM CUTOUT switches. The FAA believes these reports may open completely new investigative angles into the causes of the two crashes in Indonesia and Ethiopia."​

Its also looks like the documentation, as it relates to the TRIM STAB switches is a complete dog's breakfast

"On Apr 19th 2019, as result of the initial assessment released on Apr 16th 2019, The Aviation Herald received pages out of the 737-8 System Schematic Manual showing the circuitry involving the TRIM PRI CUTOUT and TRIM B/U CUTOUT Switches more clearly. The TRIM PRI CUTOUT switch appears under various different names on several pages of the manual, always being referenced as S272 however, the TRIM B/U CUTOUT switch also appears under different names in different locations always being references as S149 however. The graphics of chapter 27-41-11 page 101 makes clear both CUTOUT switches have more than one contact. One set of contacts delivers a signal to both FCC A and FCC B named "AUTO STAB TRIM CUTOUT" and thus would seem to support a possible re-activation of the Trim, however, a second set of contacts switches power supply to both control columns' Trim Up/Trim Down switches (effectively disabling those switches with either of the CUTOUT Switches in CUTOUT position) as well as the power supply to relay R64, which in turn disconnects the TRIM MOTOR Unit from its power supply (three phases of 115V) leaving the trim motor without any power if either of the CUTOUT Switches is in position CUTOUT. Unless this schematic diagram does not agree with the actual wiring or another fault exists in the electrical wiring, it thus appears impossible the trim motor gets energized or could re-activate with either of the CUTOUT switches in CUTOUT position."​

Full article here with diagrams

https://avherald.com/h?article=4c534c4a/0045&opt=0

There is also this I picked up on Apollohoax, posted by a user called "Bop"

This was taken from a video on a sim, showing the difficulty they would have had at that speed retrimming. remembering that they would have had to wind off tens of turns at the minimum...

This is a transcript of the now deleted video

The original sim session transcript [C=CAPT; F=FO]:
C: We have an IAS disagree.
C: So, IAS disagree memory items.
F: Autopilot if engaged, disengage.
C: Disengaged!
F: Autothrottle if engaged, disengage.
C: Disengaged!
F: Flight directors - Both up
F: With flaps up established a flight path 4 degrees and 75% N1.
C: So, 75% N1.
F: We have 77, 76,...
C: A little bit less...
F: And, there you go.
C: 4 degrees.
F: 4 degrees.

C: So I am trying to establish this now.
F: Check!
F: We are descending...?
F: We probably... Are you feeling troubled with...
F :Any trouble with the flight control?
C: Yeah, I'm trying to trim it but...
C: It continues to trim against me when I'm trimming
C: So state the malfunction, please.
F: Yeah, this doesn't look right. Looks like uh...
F: How do you feel the stabilizer, the trim system?
F: Can you control it?
C: I'm trimming it. It is responding but...
F: It's a runaway stabilizer, if you agree?
C: For every time that I trim backward, it keeps trimming forward.
F: It's trimming forward. Yeah, it's runaway stabilizer.
C: So, runaway stabilizer memory items...
C: And i'm trying to keep this thing at 4 degrees.
F: Control column, hold firmly.
C: I am... [CAPT is holding the yoke firmly with both hands]
F: Autopilot - if engaged, disengage.
C: It's disengaged.
F: Autothrottle - if engaged, disengage.
C: It's..., if you can disengage it for me, make sure that it's disengaged.
F: It's disengaged.
F: And, do you feel that the failure stop?
F: Negative?
C: No, it's still moving.
F: Stab trim cutoff switches to cutoff.
F: OK. It stops. It looks like it stops.
C: You can see now I'm using almost full back pressure here.
F: Exactly.
C: How many degrees nose down?
F: We have 4 units nose down now
C: 4 units nose down?
F: Yup.
C: OK, I'm struggling.
C: I'm actually using almost my full force to keep the aircraft level here.
F: Do you want me to help you?
C: What I would like to do.
C: Just for the sake of exercise, can you trim this forward? [to simulate MCAS trim AND]
C: See if we can reach even zero nose down.
C: And see if I can even hold it.

[FO is trying to crank the trim wheel to reach zero nose down, simulating MCAS AND]

C: So, now we are doing this just as an exercise!
C: Do not try this at home.
C: This...
C: We are at 300 knots now.
F: I'm fighting.
C: I'm sttrugling to to keep this aircraft flying.
F: My god! [FO surprised at how hard it is to trim further nose down]
C: Yeah, the thing is with higher speed the force on the stabilizer will be higher and higher as well.
C: So it becomes almost impossible to move it.
C: So we are now at about 3 degrees.
F: Yup. [FO still tries to continue trimming nose down, the wheels is so difficult to spin]
C: We're still about 3 degrees away from full nose down trim.
C: And I am using everything that I have. [CAPT still holding on to his yoke with both hands]
F: My God ! [the trim wheel barely move for the down trim]
C: This is realistic guys.
C: This is how much of effort it would take to trim the stabilizer at this kind of speed.
C: Umph... [Capt is still trying to hold on to his yoke with his hands]
C: I'm just in control of it, though. But it's getting harder and harder.
C: And remember we're still 2.5 degrees away...
F: My God! [FO still struggles to spin the refused-to-be-spun trim wheel]
C: It's not possible, is it?
C: All right, we stop at that.

C: The reason that we have to try...
C: The reason we have to trim this manually is because the normal trim system wouldn't do this, OK.
C: It would require manual trim to get it away from this.
C: That's fine.
C: Trim it backward. [This time to illustrate the effort to trim the nose back up after "MCAS" brought the AC further nose down]
C: Trim it backward as you can.
F: Oh my God! I couldn't... [FO can't spin the wheel to trim up]
C: OK.
C: Eh...
C: Juan, press the red button! [CAPT called the sim operator...]
C: Press the red button now. [to stop the sim session]
C: This is at 340 knots.
C: And the trim is at...It's still at almost 2.5 degrees.
F: Yeah, 2.5 degrees.

This graphically illustrates the extreme difficulty in executing the runaway trim procedure (as detailed in the QRH) at any sort of flight speed. Even at 300 knots, the First Officer finds it impossible to trim the nose up.

Also, something else I didn't realise until recently, is that the MCAS relies solely on the pilots AoA vane! The upshot of this is obvious..... a single, faulty AoA transmitter can cause an MCAS fault, the corrective procedure for which is basically, kill the two TRIM CUTOUT switches (which removes electrical power from the trim motors operating the stabiliser jackscrew), and trim out the aircraft manually using the trim wheels.

Well, that might sound fine on paper, but in practice, it it extremely difficult to achieve, and its likely the crew will be unable to prevent the airliner going down.

 

[Darat]

It sounds more and more like Boeing's commercial needs were allowed to force engineering down routes they should have never taken.

 

[Bob001]

It sounds more and more like Boeing's commercial needs were allowed to force engineering down routes they should have never taken.

Yep.

A veteran commercial pilot and software engineer with over three decades of experience has just written the most damning account of the recent Boeing 737 fiasco. At one level, author Gregory Travis has provided us with the most detailed account of why a particular plane model once synonymous with reliability became a techno-death trap. But ultimately, his story is a parable of all that is wrong with 21st-century capitalism; Boeing has become a company that embodies all of its worst pathologies. It has a totally unsustainable business model—one that has persistently ignored the risks of excessive offshoring, the pitfalls of divorcing engineering from the basic R&D function, the perils of “demodularization,” and the perverse incentives of “shareholder capitalism,” whereby basic safety concerns have repeatedly been sacrificed at the altar of greed. It’s also a devastating takedown of a company that once represented the apex of civilian aviation, whose dominance has been steadily eroded as it has increased its toxic ties to the U.S. military. In that sense it mirrors the decline of America as a manufacturing superpower. And finally, it shows a company displaying a complete loss of human perspective in the “man vs. machine” debate.

https://www.salon.com/2019/04/27/bo...ndictment-of-21st-century-capitalism_partner/

 

[theprestige]

It sounds more and more like Boeing's commercial needs were allowed to force engineering down routes they should have never taken.

I'm pretty sure trying to mate more fuel-efficient engines with existing airframe designs was *always* a route Boeing's engineers should have taken, specifically because of their business needs.

 

[Darat]

I'm pretty sure trying to mate more fuel-efficient engines with existing airframe designs was *always* a route Boeing's engineers should have taken, specifically because of their business needs.

Who has said it wasn't?

 

[Trebuchet]

Yep.


https://www.salon.com/2019/04/27/bo...ndictment-of-21st-century-capitalism_partner/

Sorry, but this...

“In the old days, when cables connected the pilot’s controls to the flying surfaces, you had to pull up, hard, if the airplane was trimmed to descend. You had to push, hard, if the airplane was trimmed to ascend. With computer oversight there is a loss of natural sense in the controls. In the 737 Max, there is no real ‘natural feel’…

“There is only an artificial feel, a feeling that the computer wants the pilots to feel. And sometimes, it doesn’t feel so great.

“When the flight computer trims the airplane to descend, because the MCAS system thinks it’s about to stall, a set of motors and jacks push the pilot’s control columns forward. It turns out that the flight management computer can put a lot of force into that column—indeed, so much force that a human pilot can quickly become exhausted trying to pull the column back, trying to tell the computer that this really, really should not be happening.” (Emphasis added.)

...is pretty close to being Not Even Wrong. MCAS doesn't affect the control columns, it trims the stabilizer. And the 737MAX still has the column connected to the elevators by cables; in fact it can move the elevators even with hydraulics out. The only new fly-by-wire on the airplane is for the spoilers, which had no involvement in the accidents.
Factual errors like that, and politicized statements like "increased its toxic ties to the U.S. military" pretty much destroy the credibility of the article.

That said, The Seattle Times had a headline the other day about Boeing saying there was "no technical slip" in the design. If true, Boeing management needs to stop taking advice from lawyers.

ETA: Here's a link to the IEEE article the Salon one is based on. You'll have to sign up for an account. Some of it is almost as bad.

 

[Bob001]

Sorry, but this...

...is pretty close to being Not Even Wrong. MCAS doesn't affect the control columns, it trims the stabilizer. And the 737MAX still has the column connected to the elevators by cables; in fact it can move the elevators even with hydraulics out. The only new fly-by-wire on the airplane is for the spoilers, which had no involvement in the accidents.
Factual errors like that, and politicized statements like "increased its toxic ties to the U.S. military" pretty much destroy the credibility of the article.

That said, The Seattle Times had a headline the other day about Boeing saying there was "no technical slip" in the design. If true, Boeing management needs to stop taking advice from lawyers.

ETA: Here's a link to the IEEE article the Salon one is based on. You'll have to sign up for an account. Some of it is almost as bad.

No link here. But I found it.
https://spectrum.ieee.org/aerospace...37-max-disaster-looks-to-a-software-developer

As a non-pilot, I am completely ignorant of the technology that carries giant metal tubes through the clouds. But the author says he's a pilot with 30 years of experience, and his broader point is that the new software design can keep the pilots from overriding the computer, and corporate interests were behind its introduction. As a layperson, I can't imagine circumstances where the pilot shouldn't be able to take and keep control of the plane, nor should it ever be possible for the computer to steer a plane into the ground.

 

[smartcooky]

As a non-pilot, I am completely ignorant of the technology that carries giant metal tubes through the clouds. But the author says he's a pilot with 30 years of experience, and his broader point is that the new software design can keep the pilots from overriding the computer, and corporate interests were behind its introduction. As a layperson, I can't imagine circumstances where the pilot shouldn't be able to take and keep control of the plane, nor should it ever be possible for the computer to steer a plane into the ground.

Well, as a retired aeronautical engineer (and a qualified, but not current, private pilot) I agree 100%, in spades

Yes, automation has brought the number of air incidents and accidents attributable to pilot error down dramatically, but there have also been quite a number of fatal accidents in which the automation has been a significant contributing factor in, and it is beginning to appear in these two cases, LA610 & E302, the outright cause of the accident.

Automation is limited by programming, and automatic flight control systems can only do what they are programmed to do; they can only recognise faults and events that they are programmed to recognise; they can only apply solutions that they are programmed to apply. A computer cannot take two unrelated things it has never encountered before and figure out at a workaround; for example, United 232. No computer flight control system could ever have reasoned of its own accord that a DC10 with a 100% failure of the triple-redundant hydraulic system, could be flown and controlled to a limited extent, using differential thrust between three engines.

Where pilots have it over automation is that pilots can reason. They can take their training, see a situation that they have never seen before, and connecting seemingly unrelated things to arrive at a workaround.

 

[ponderingturtle]

Hmm wonder if anything with come of these whistelblowers.

https://www.cbsnews.com/news/boeing-737-max-8-at-least-4-potential-whistleblower-calls-made-to-faa-about-jetliner/

 

[Trebuchet]

No link here. But I found it.
https://spectrum.ieee.org/aerospace...37-max-disaster-looks-to-a-software-developer

As a non-pilot, I am completely ignorant of the technology that carries giant metal tubes through the clouds. But the author says he's a pilot with 30 years of experience, and his broader point is that the new software design can keep the pilots from overriding the computer, and corporate interests were behind its introduction. As a layperson, I can't imagine circumstances where the pilot shouldn't be able to take and keep control of the plane, nor should it ever be possible for the computer to steer a plane into the ground.

Sorry about the forgotten link.

For a long time, having the pilot in ultimate control was a bit of a selling point for Boeing vs Airbus. During my time there it was getting harder and harder to keep it that way.
One problem with the article is that the author is a GA (General Aviation) pilot. He flies a Cessna. He doesn't seem to know how the systems in actual airliners work.

 

[Ranb]

Some interesting stuff on Boeing.
http://chuckspinney.blogspot.com/

Ranb

 

[Trebuchet]

Some interesting stuff on Boeing.
http://chuckspinney.blogspot.com/

Ranb

As I've said before, I'm glad I'm not there any more. But some of this stuff was going on long before I retired. I found the Hart-Smith (that's one guy) report, link number 5 in that article on a Boeing server years ago, and printed it so I'd have it if they locked it up. They did. The author was a world-class expert in composites and was writing about the culture at McDonnell-Douglas. That culture became pervasive at Boeing immediately after the merger. It was commonly said that "McDonnell bought Boeing with Boeing's money." (Omission of "Douglas" there is intentional."
The Charleston 787 plant was and is a union bust, pure and simple. The IAM (International Association of Machinists, the factory workers' union) sued Boeing for using the threat of moving 737 production to Charleston as leverage in negotiations. That's illegal. Boeing had to settle because an exec had actually boasted of doing that to the financial media. No 737's in Charleston.

 

[rjh01]

This is well worth a watch.
The real reason Boeing's new plane crashed twice
https://www.youtube.com/watch?v=H2tuKiiznsY

The plane is a very old design that has been updated several times, as in one too many times. I think the real solution is to scrap the plane.

 

[rjh01]

Here is another video on the same subject https://www.youtube.com/watch?v=BfNEOfEGe3I

 

[ponderingturtle]

Self certification and regulation FTW!

https://www.npr.org/2019/05/06/720553748/boeing-knew-about-737-max-sensor-problem-before-plane-crash-in-indonesia

They knew about the problem for a year before the first crash. And I am sure everyone will be going over how regulations are totally unnecessary because the bad press from doing what Boeing did would be sure to kill it.

Anyone placing bets of if we will see Boeing be allowed to die?

 

[Bob001]

More on behind-the-scene machinations at Boeing:

Before approving plans for a new jetliner called the 737 Max, Boeing’s board of directors discussed how quickly and cheaply it could be built to compete with a rival — but the members didn’t ask detailed questions about the airplane’s safety, according to three people present for the meetings.

https://www.washingtonpost.com/busi...droom-amid-max-crisis/?utm_term=.a61770d2acde