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MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

Old 4th Jul 2019, 00:40
  #1001 (permalink)  
 
Join Date: Aug 2013
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Originally Posted by wonkazoo View Post
Technically there are already as many parked as have been delivered. And a few more!! (Because they are all parked...)

This useless post brought to you by Light Always Airways. (LAA) "We spend lesser so you can go higher!!"

On an unrelated note: Who builds an airplane with two switches ostensibly in series, but in reality not so for one channel, to do the job of just one previously?? Who states that these are both "redundant??" when clearly they do different things?? What does that open channel between the FCC and God knows actually do, and since it didn't exist before can we safely accept that it is an artifact of MCAS??

I could go on for hours. The one thing our favorite expert and everyone else has right is this: We don't know squat. We know a lot, and from that we may draw inferences, but as to actual facts: We got stinko.

Here's the thing I do not understand (This will be the end of this lumbering and highly lubricated post I promise): Boeing creates a shit system that kills north of 300 people. OK,

Because I treasure all my fellow travelers, YokoDriver I'll help you out here: Boeing killed 300+ with the help of some less than stellar piloting.

OK, that's not good by any measure.

But then...

A few months go by...

And, according to YokoDriver Boeing gives the FAA some software to play with. (Now let's be clear here. By play with we mean molest completely and bend any way you can to try to make it break. Because that's what you do when your previous offering killed 300+ right??)

Anyway, and the point of the entire sad story is this: No matter how they got here, when the simulation was run:

THE FAA TEST PILOTS BARELY RECOVERED THE AIRPLANE AFTER IT TRIED TO SCREW ITSELF INTO THE GROUND.

Key phrase there: "THE AIRPLANE TRIED TO SCREW ITSELF INTO THE GROUND."

Only one of two possible things happened here.

a) The software tested was Boeing's original brew. Meaning not only is the now known MCAS AOA failure mode present, there was ANOTHER ONE, a failure mode that would try to screw the airplane into the ground.

or

b) Boeing sent over a "NEW" software package, and it had a failure mode that would try to screw the airplane into the ground.

Previous posters have argued indignantly using some of the points above, but seeing them in full is illuminating to say the least.

Can anyone please tell me why heads didn't explode with the headline last Thursday??

Either Boeing software had TWO flaws that would try to make a smoking hole in the ground, or they sent a new updated version to the FAA for a test-run with a flaw that would try to make a smoking hole in the ground.

Sorry for the lugubrious rant-
dce
Problem is, you can test that software well under normal conditions and under discrete non-normal conditions, but you cannot possibly test for every potential software error because there are far too many. So the methodology of Design Assurance is used, to the degree determined by the hazard classification.

This system has twice demonstrated that its malfunction (even with software acting as intended) must be classified as Catastrophic. This means that proper compliance requires DAL A. Question is, what is the current DAL of this software? While coding changes might be proposed and completed with relative simplicity, an upgrade of the DAL requires a complete reaccomplishment of the software development.

Not a trivial task at all, and one I fear the FAA would not choose to impose. Hopefully, other CAA, including EASA, will not be so accommodating. We’ll see. Well maybe they won’t let us see.
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Old 4th Jul 2019, 01:43
  #1002 (permalink)  
 
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can someone who is conversant with the FAA regs point me towards any parts dealing with what the requirements for graceful disengagement of automation in case of invalid input, or anywhere where suppression of false alarms in case of invalid input is discussed?

thanks
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Old 4th Jul 2019, 02:53
  #1003 (permalink)  
 
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Originally Posted by phylosocopter
can someone who is conversant with the FAA regs point me towards any parts dealing with what the requirements for graceful disengagement of automation in case of invalid input, or anywhere where suppression of false alarms in case of invalid input is discussed?

§ 25.672 Stability augmentation and automatic and power-operated systems

If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show compliance with the flight characteristics requirements of this part, such systems must comply with § 25.671 and the following:

(a) A warning which is clearly distinguishable to the pilot under expected flight conditions without requiring his attention must be provided for any failure in the stability augmentation system or in any other automatic or power-operated system which could result in an unsafe condition if the pilot were not aware of the failure. Warning systems must not activate the control systems.

(b) The design of the stability augmentation system or of any other automatic or power-operated system must permit initial counteraction of failuresof the type specified in § 25.671(c) without requiring exceptional pilot skill or strength, by either the deactivation of the system, or a failed portion thereof, or by overriding the failure by movement of the flight controls in the normal sense.

(c) It must be shown that after any single failure of the stability augmentation system or any other automatic or power-operated system -

(1) The airplane is safely controllable when the failure or malfunction occurs at any speed or altitude within the approved operating limitations that is critical for the type of failure being considered;

(2) The controllability and maneuverability requirements of this part are met within a practical operational flight envelope (for example, speed, altitude, normal acceleration, and airplaneconfigurations) which is described in the Airplane Flight Manual; and

(3) The trim, stability, and stall characteristics are not impaired below a level needed to permit continued safe flight and landing.

[Amdt. 25-23, [url=https://www.law.cornell.edu/rio/citation/35_FR_5675]35 FR 5675 Apr. 8, 1970]
source fdr post#17 MCAS ALTITUDE V ATTITUDE ??
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Old 4th Jul 2019, 03:24
  #1004 (permalink)  
 
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Originally Posted by Loose rivets View Post
There has to be the potential for this aircraft to become a basic flying machine.
Not THIS airplane. It's "not stable enough", aerodynamically.

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Old 4th Jul 2019, 03:42
  #1005 (permalink)  
 
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Not THIS airplane. It's "not stable enough", aerodynamically.
It is quite amazing that a small group of people keep repeating this. It will not make it true.

The 737 is stable. It can be hand flown. MCAS does not operate with AP in or flaps extended. The MCAS was only to increase back pressure required near the critical angle (stall) NOT to make the aircraft stable enough to fly.

How many times does this have to be corrected?
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Old 4th Jul 2019, 05:02
  #1006 (permalink)  
 
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Originally Posted by Alchad View Post


Yoko1

Have to give you credit for one thing, your speed of typing and ability to compose an arguement has me very impressed. A mere 8 minutes after replying to my post, your respond to Wonkazoos post in a very well drafted piece including a number of quotes from other articles. For a self confessed 737 pilot you missed an alternative career in journalism.

Alchad
Yeah, I could post counter-arguments a mile long but I'm not going to as there is no point. YokoDriver will characterize them once again and we can go round and round for hours but nothing will be accomplished. Further I doubt the veracity, identity and actual animation of the single individual posting under that title- for reasons you identified above. Also (And I don't say this unkindly) if YokoDriver is in fact a lowly air commander of the skies he is (by far) the most verbose, eloquent, and anti-straightforward writing version of that role I have ever seen. Full stop.

It is also clear that the individual(s) posting are not posting for this audience but for another, who may never see PPRuNe until these threads appear in a court case somewhere to show how the "knowledgeable opinions" were all over the place. Sadly many here engage in good faith, thinking that the individual is a single entity and is every bit of what he/she says they are. Thus not a troll in the traditional sense, but nonetheless an individual who feeds on creating division, diversion and hammering home their own core themes, with an overall goal that is not in view of the rest of the forum behind literally every word of every post.

My identity is public. So if I write something objectionable it may impact me personally, which is all you need to really know about the main difference between me and YokoPilot and what weight you should give our respective words.

Warm regards-
dce
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Old 4th Jul 2019, 05:39
  #1007 (permalink)  
568
 
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Originally Posted by wonkazoo View Post
Yeah, I could post counter-arguments a mile long but I'm not going to as there is no point. YokoDriver will characterize them once again and we can go round and round for hours but nothing will be accomplished. Further I doubt the veracity, identity and actual animation of the single individual posting under that title- for reasons you identified above. Also (And I don't say this unkindly) if YokoDriver is in fact a lowly air commander of the skies he is (by far) the most verbose, eloquent, and anti-straightforward writing version of that role I have ever seen. Full stop.

It is also clear that the individual(s) posting are not posting for this audience but for another, who may never see PPRuNe until these threads appear in a court case somewhere to show how the "knowledgeable opinions" were all over the place. Sadly many here engage in good faith, thinking that the individual is a single entity and is every bit of what he/she says they are. Thus not a troll in the traditional sense, but nonetheless an individual who feeds on creating division, diversion and hammering home their own core themes, with an overall goal that is not in view of the rest of the forum behind literally every word of every post.

My identity is public. So if I write something objectionable it may impact me personally, which is all you need to really know about the main difference between me and YokoPilot and what weight you should give our respective words.

Warm regards-
dce
It has been very interesting reading your responses and yoko1's missives.For a Company as big as Boeing it would not surprise me that they have there "lawyers" pouring over the web in search of "technical" discussions. One would assume that these "lawyers" now realize they have their work cut out to meet the demand of potential law suits.Don't really care for lawyers, but I do for the families of the loved ones lost in these accidents.For closure for all of these families, let us all take a moment to reflect on the gravity of the situation and ensure that we all channel our efforts to ensure that the Boeing Company make strides towards openness, safety, training and honesty for our pilot cadre and for consumers flying in the 737.
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Old 4th Jul 2019, 06:17
  #1008 (permalink)  
 
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Originally Posted by 568 View Post
It has been very interesting reading your responses and yoko1's missives.For a Company as big as Boeing it would not surprise me that they have there "lawyers" pouring over the web in search of "technical" discussions. One would assume that these "lawyers" now realize they have their work cut out to meet the demand of potential law suits.Don't really care for lawyers, but I do for the families of the loved ones lost in these accidents.For closure for all of these families, let us all take a moment to reflect on the gravity of the situation and ensure that we all channel our efforts to ensure that the Boeing Company make strides towards openness, safety, training and honesty for our pilot cadre and for consumers flying in the 737.
Well said.

One of the things that brought me to PPRuNe maybe ten years ago was the fact that pretty much everyone who posted, from self-admitted SLF to 30,000 ATP flying heavy iron, all were focused on sharing their experience and expertise for the greater or common good. Passionate people involved in sharing ideas, knowledge and experience, without an agenda, to try to find some sanity in the world. (Can you tell I usually visited when something metal and heavy flew into the ground somewhere in the world??)

What I have seen in the last six months are examples that are discordant and do not follow with that former description of PPRuNe. These examples are in most cases polished, speak in dogmatic or nuanced catchphrases that are not intended to educate or share, but to shift a discussion either on to a certain topic or off of another one. They are also stupendously verbose and frequently consume every conversation and all participants with the sheer volume of their nuanced work. And nuance is the key word. A malcontent who truly believed the pilots were to blame and eff-all anyone who says different would be instantly recognizable. Someone who says, "well yes, there's Boeing, and the FAA, and all the others who contributed, but really folks, it's the guys flying the plane who are at fault..." And then repeats that phrase but carefully reworded: "The pilots could have recovered the airplane if only they had followed the checklist," or "all they had to do was follow the checklist," or "the first Lion Air incident showed that it was survivable. Why are you arguing about it being survivable?" is basically being coy.

This repeats and repeats and repeats. 6 posts per day in some cases. For months now.

PPRuNe appears to have been, I hate to say it, been compromised and is (I believe) being used as a messaging tool by outside entities. I know this because for the first time I am seeing something I never saw before: Someone proselytizing for a certain belief- in this case the fault of the pilots of the doomed airplanes. That same someone singularly well-informed to boot. Sure, they have branched out to other areas in their posts, but every four posts or so you will see a return to that area of expertise: "It was not Boeing- it was those damn foreigners who flew a perfectly good airplane into the ground..."

In the past PPRuNe was a (relatively) free exchange of ideas from individuals with no dog in the fight. No one was selling anything and everyone just wanted to know what the eff happened.

By all appearances that is simply not so today.

Thank you for listening,
dce.
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Old 4th Jul 2019, 06:25
  #1009 (permalink)  
 
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Originally Posted by wonkazoo View Post
Well said.

What I have seen in the last six months are examples that are discordant and do not follow with that former description of PPRuNe. These examples are in most cases polished, speak in dogmatic or nuanced catchphrases that are not intended to educate or share, but to shift a discussion either on to a certain topic or off of another one.
And it looks like their PPRuNe joining dates are (were because some do no longer appear on PPRuNe) all since March 2019....!

.
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Old 4th Jul 2019, 06:44
  #1010 (permalink)  
 
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Originally Posted by wonkazoo View Post
if YokoDriver is in fact a lowly air commander of the skies
Could I suggest that if you have any evidence to the contrary, you post it for all to see ?

Otherwise, give the innuendo a rest.
DaveReidUK is online now  
Old 4th Jul 2019, 07:01
  #1011 (permalink)  
 
Join Date: Nov 2015
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Originally Posted by DaveReidUK View Post
Could I suggest that if you have any evidence to the contrary, you post it for all to see ?

Otherwise, give the innuendo a rest.
Yoko1 wrote the following 1,551 grammatically perfect words just a short while ago. 1,200 of them were posted within a span of just slightly more than 30 minutes. I write fast, in fact faster than anyone I know. For damn sure faster than any airline pilot I know, of which there are a few. Yoko1 beats both me and any airline pilot by a wide margin. He/she also parsed my somewhat complex offerings to a high degree, finding arguementative weakness where there was any to find. In fact they parsed it so cleanly and exactly it sort of reads like... Well you get the idea.

Perhaps you write this fast, and you know other airline pilots who do as well. In which case these observations are meaningless. But for most of the folks reading this (I think) spooling off 1,551 grammatically perfect (and legally perfect too!) words in the span of a half hour is a feat they have never either attempted or accomplished.

Here you go- and remember, you asked for it!!:

"While I don't disagree in theory, this approach has two distinct problems.

First, as I have mentioned, there has been a very definite shift in philosophy regarding non-normal (formerly known as emergency) procedures industry wide. I don't know if the change was driven by manufacturers, regulators, operators, or some combination of the three, but it has been in place for awhile and unlikely to change. There is a very great reluctance to conduct any action that may be seen as troubleshooting a malfunction which very much includes restoring power to a system, or part thereof, that has malfunctioned. There is probably some historical safety data to back up this philosophy, but there are times when I believe it is overly constraining. Nevertheless, the intent behind most of the significant non-normals nowadays is to shut down and/or contain the malfunction and land the aircraft with what you have left.

Second, let's just say that the switchology was changed back to the NG configuration and we inserted this new step into the existing Runaway Stab Trim procedure. For the sake of discussion we will call it Step 6 since Step 5 is where the cutout switches are used. In order to get to Step 6, the pilots must first correctly navigate Steps 1 thru 5. Since neither accident crew chose to utilize the existing Runaway Stab procedure, much less work through it step by step (and particularly that very critical Step 2), then a new switch with a new step really would not have solved their problem.

As I mentioned above, new tools don't help much if they are not used or used ineffectively. The accident crews had several tools available to them that they either did not use or did not use effectively. I think a bit more time and energy should be directed to figuring out why that was the case before we go down the path of creating new tools.

You are falling into the cognitive trap of believing that this must be an either/or proposition. Problems with design and problems with training are not mutually exclusive. In fact, I'm willing to bet that the final reports are going to have a long list of primary and contributory causes. It would be quite a shame to fix just one of them.

If someone's head is exploding, then that person doesn't really understand what was reported. Frankly, I'm a little surprised that you are bringing this up again. You quoted a post of mine a few days back which explained exactly why this is not the smoking gun that everyone wants it to be, but you have apparently chosen to ignore that response and slap this red herring back on the table.

Let's go through it again, with a little more detail. First of all, this is not a smoking gun because it is not even the same gun. The problem was discovered when the new, yet to be flight-certifiedFCC software was being stress-tested in a Boeing engineering simulator. This simulator can be used to plug in different components of flight control hardware and software during both development and test phases and is part of the certification process of any new aircraft or related subsystems. The tests that were being conducted intentionally introduced faults into the FCC in order to see how it would respond. Normally, a fault on a single FCC should attempt to hand off the process to a different processor on the same FCC, or failing that, to a different FCC (there are two on the 737). The test did not involve the MCAS subroutines of the new FCC software.

This news was reported through several outlets, but Leeham New's seems to have the best detail:

Bjorn’s Corner: New pitch trim issue forces further changes to 737 MAX software

Quoting the article:

As currently understood, the MCAS software on the accident aircraft did not input nose down trim because of a fault, but simply because it performed a task exactly how it was programmed to do so. Yes, it was ill-conceived program, but there is no indication that it created a fault condition.

All the test above tells us is that the new software has either a coding issue (which may involve just reprogramming work) or it is demanding more than the processor can handle (which may involve a change in processors). There was extensive discussion previously in this thread by individuals with background in this kind of work who explained all the ways in which errors could have been introduced into the new software.

Also important to understand is that this type of testing was performed on the original Flight Control components (hardware/firmware/software) that were part of the originally certified aircraft. Certainly one might suggest that this testing missed something. Possible, but this is where the accident investigation process steps in.

In order to determine the cause(s) of an accident, to include an attempt to replicate all the physical and electronic evidence left behind, the accident investigators will run every suspect component through a battery of tests. Since the actual components were destroyed, it is almost certain that the investigation teams pulled similar components from the field and then used the same (or similar) Boeing engineering simulator to test these components for all manner of possible failures, including the exact tests run by the FAA as described above. Ideally, these components would have been produced in the same lots as the those in the accident aircraft. Since there hasn't been much reticence in reporting all the other existing flaws with the MCAS and related software, it doesn't seem likely that an issue that caused a fault like the one reported for the new software would be selectively concealed from the public. Another item for the "Dog that did not bark" file.

Back to the Leeham article which first quotes from a so-called 8-K public filing:

That last point is very important. If Boeing was aware of an issue that might further delay the re-certification of the MAX, then it must provide some kind of disclosure since it is material information that would effect the stock price. Any issues with components of the Main Electric Trim system would likely require significant rework (redesign and/or replacement of switches, wires, relays, motors, controller, etc.) and add to the already known delay. By SEC rules, this type of delay would require a similar 8-K report by Boeing. One more dog that isn't barking.

Lots and lots of dogs not barking, and there is a very good reason for it.

Possibly, but let me throw out one more thought that relates to both why the procedure was changed and why the crew might not have made the decision you think they would.

The Boeing trim system found on the 707, 727, and 737 has evolved over time. Initially, there was a fast motor for the pilots use, and a slower motor for the autopilot (back when the autopilot was the only other source of electric stab trim). That logic continued even as systems were added and more things could move the stabilizer (Mach Trim, Speed Trim). The thumb switch moved the trim quickly, the automatics moved it slowly. I don't know about the 737 classics, but on the 737NG the logic also included flap position. Flaps down trim was always faster than flaps up trim, and pilot trim was always faster than automatic trim. However, this logic now created four distinct trim speeds (0.4/0.2/0.27/0.09 deg/sec)

Part of the old procedure in isolating the malfunctioning trim system was a subjective evaluation of whether it was moving fast or slow. If if was moving fast, then the Main Electric Trim was suspect. If it was moving slow, then one of the automatic systems. However, with the existence of four distinct speeds and the fact that the "fast" automatic was now faster than the "slow" Main Electric, there was some concern that pilots might misidentify the malfunctioning system, use the wrong cutout, and aggravate the problem. Keep in mind that a runaway stab is not anything you want to dally with - prompt and correct action are critical. This was one of the drivers for simplifying the procedure in the first place.

One of the issues that has been highlighted with the original MCAS design is that it operated at a higher speed than the Main Electric Trim in the flaps up configuration. Thus, it is entirely possible that this faster movement could have been interpreted as a problem with the Main Electric Trim, and not one of the automatic sources. Logically, then the crew would attempt to restore the automatic trim thus 1) reintroducing the runaway while 2) taking away the most effective tool to stop it - namely the Main Electric Trim.

In fact, this is effectively what happened with ET302. They did not properly run the Runaway Stab procedure, they cutout the trim in a significant out-of-trim conditions, and in an act of desperation they restored the malfunctioning system which promptly drove the stab to the stop. It should be noted this crew also had the opportunity to reactivate the cutout switch, but did not, probably because the MCAS movement at the excessive speed they were flying created such a strong negative g force that they were startled or thrown off balance."

************************************************************ ************
If you would like a comprehensive list of another User ID that appeared and then disappeared here you go: https://www.pprune.org/search.php?se...0&pp=25&page=2

I don't have it in me to copy and past the tens of thousands of words that the individual(s) offered before being banned by mods, but it is not a short read if you choose to parse through it. 209 posts over just slightly more than 30 days.

Over and out-
dce
wonkazoo is offline  
Old 4th Jul 2019, 07:39
  #1012 (permalink)  
 
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Originally Posted by GlobalNav View Post

Problem is, you can test that software well under normal conditions and under discrete non-normal conditions, but you cannot possibly test for every potential software error because there are far too many. So the methodology of Design Assurance is used, to the degree determined by the hazard classification.

This system has twice demonstrated that its malfunction (even with software acting as intended) must be classified as Catastrophic. This means that proper compliance requires DAL A. Question is, what is the current DAL of this software? While coding changes might be proposed and completed with relative simplicity, an upgrade of the DAL requires a complete reaccomplishment of the software development.

Not a trivial task at all, and one I fear the FAA would not choose to impose. Hopefully, other CAA, including EASA, will not be so accommodating. We’ll see. Well maybe they won’t let us see.

That's exactly the point!
Mills of bureaucracy are turning slowly but are grinding fine. I'm confident that FAA has just changed teams.
After all the "promotion" of a certain fault's overall effect to hazardous has just been a week ago.

There is one small issue in your statment I would like highlight:

what is the current DAL of this software?
DALs are not only defined for software but also for hardware, requirments are coverd in DO-254.

Originally Posted by HighWind View Post
The Falcon 7X FBW system clearly has the functionality to monitor runaway, I just failed in the case of HB-JFN loss of control after pitch trim runaway.
Thank you for that link. I have become a fan of BEA lately. This report is defenitly worth a read

So what we have at Falcon7x is a failure that was in the FMEA but whose local effects have been misjudged. A failure of a voltage regulator in the interal powersupply lead to a runaway ANU trim.
Because the overall hardware and software architecture was designed to DAL-A, it was no problem to fill that gap by adding code that verifies the integrity of the voltage regulator.

What HighWind, who has obviously some professional exposure to functional safety in industrial automation, and I who had some albeit little exposure to functional safety in automotive engineering (I successfully avoided becoming too involved), are questioning:
Originally Posted by HighWind View Post
Looking at the electrical diagram for the electrical trimming, I’m not sure if I can get this approved for anything but SIL1.
Originally Posted by BDAttitude View Post
Could you please have a look if the actuators electronics - which is hardware and software - have been designed to a suitable design assurance level. Which would be DAL-B? DAL-A?
Uncontrolled dive is just a bit-flip away.
​​​​​Is the overall system architecture of the horizontal stabilizer trim as we see it today anywhere near DAL-A?
I don't think so. Should it be, after the reevalutation pf the failure effects of a high speed electric trim runaway? I think so.

No link to the accidents suggested. To put it in the words of someone who I believe is a technical writer from Boeing: No smoking gun, but a loaded and unlocked gun lying on the table.

We shall see.
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Old 4th Jul 2019, 07:47
  #1013 (permalink)  
 
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Originally Posted by Icarus2001 View Post
It is quite amazing that a small group of people keep repeating this. It will not make it true.

The 737 is stable. It can be hand flown. MCAS does not operate with AP in or flaps extended. The MCAS was only to increase back pressure required near the critical angle (stall) NOT to make the aircraft stable enough to fly.

How many times does this have to be corrected?
I think, you are not up to date. It even isn't challenged by the Boeing submarine, that the plane is lacking the stability required by certification standards.
The dispute remaining - unsolvable due to lack of data - is:
Not stable enough - but still stable throughout the envelope.
Not stable enough - but critically stable at some points of the envelope.
Not stable enough - and unstable at some points of the envelope.

To me the not stable enough for certification w/o MCAS is sufficient.
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Old 4th Jul 2019, 08:35
  #1014 (permalink)  
 
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Originally Posted by DaveReidUK View Post
Could I suggest that if you have any evidence to the contrary, you post it for all to see ?

Otherwise, give the innuendo a rest.
Dave, after the discussions on previous threads I'm afraid I'm suspicious about this too.

It would help if PPRuNe identified real pilots. I don't mean close the forum to non-pilots, because engineering, human factors etc is an essential part of the discussion. But if anyone wants to say they're a pilot, provide your license details and type ratings to PPRuNe. Then you get a little sticker on your avatar saying ATPL verified. Or PPL SEL etc. No need to publish real identities.

At least then we'd have a bit more confidence in what was bring said.
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Old 4th Jul 2019, 08:42
  #1015 (permalink)  
 
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Must say have suspicion about Yoko1 after a brief exchange.
Posts 630, 632, and 657.
He was quoting the static stability requirements of FAR25 in some detail, after stating that there are two types of stability - static and dynamic.
My query was: how did he know the pitch problem behind the MCAS was not related to manoeuvre stability?
He replied requesting a FAR 25 definition of manoeuvre stability.
I then realized that he was just parroting FAR 25, possibly for a reason unknown to me.
It is true that the actual para heading in FAR 25 do not mention manoeuvre stability, but it is everywhere, either implied or directly mentioned, in the controllability and out of trim requirements, and also in the various AC25-7 revisions.
It just seems to me that any pilot claiming detailed knowledge of FAR25 longitudinal static stability requirements would be aware of general manoeuvre stability theory and how it is addressed within FAR25.
May be Yoko1 is part of the infinite monkey typing troop or maybe this particular rabbit hole was not on the agenda.
Just a simple exchange, but from my ex TP background, didn't add up.

Last edited by zzuf; 4th Jul 2019 at 08:53.
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Old 4th Jul 2019, 09:13
  #1016 (permalink)  
 
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Originally Posted by yoko1 View Post
[...] but we are procedurally not allowed to do so. Once upon a time, it was allowed at the Captain's discretion, but no longer. A Captain can always take a chance and play the "Captain's Emergency Authority" card and do what he/she thinks is needed to save the ship, but he/she would then be counting on a sympathetic Fed/Supervisor/Chief Pilot to agree with his reasoning at the subsequent hearing.
Let's not forget my "favorite" post hoc judgements: the veiled stabs here on PPRuNe about "They didn't [perfectly] follow the [two or three simultaneous] memory item[s]" or "they did not arrive at step X [hence they did not know what they where doing]", "they did not do step X [so they were fumbling around]"... Instead of asking what prompted them to deviate, or prevented them to do what, in hindsight, is (sooo)⁹ obvious (FlY tHe [PeRfEcTlY FiNe] PlAnE™), while changing the goalpost every time a new bit of information comes out.

Mere [frustrated] SLF here.
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Old 4th Jul 2019, 11:41
  #1017 (permalink)  
 
Join Date: Jan 2008
Location: UK
Posts: 12
Would be great to see the e-cab/FAA test pilot video to help get this SLF back into any modern Boeing variant. Hopefully Boeing's confidence in the quality of their engineering and safe product design will shine through.. I see absolutely no reason why they could not do this unless there was something they wanted to hide.
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Old 4th Jul 2019, 12:18
  #1018 (permalink)  
 
Join Date: May 2019
Location: Somewhere over the rainbow...
Posts: 0
Wow. Just wow.

I take a break for a few hours it seems an small group led by Mr. Wonkozoo seems to have got themselves in a bit of a lather. I will note for the record, that virtually none of their responses contained any actual facts in response to any of the information I posted, and were merely thinly disguised ad hominem attacks. I realize that's just what some folks do when the facts aren't on their side, but I'm still quite disappointed.

So some people think I write well. Thank you, for the compliment, because I take pride in my writing. I try to communicate as clearly as I can, and (unlike a few folks here), I attempt to research the topic thoroughly. I don't claim to be an expert in a lot of these topics, but I've spent a lot of time offline trying to educate myself. Can some of you say the same?

As to the supposed mystery of the "speed typing," it's not much of a mystery at all. Except for the short sentence or two pieces, I draft most of my responses offline, and I usually have multiple items going at once. I'll review, edit, fact check, and polish for awhile. When I'm satisfied, I'll start posting them which is why they can appear in quick succession. The work the Mr. Wonk implies was crafted in minutes actually took a little over two hours. So yes, when I put a great deal of work into a piece and someone can only come up with a retort that is the equivalent of an online "yuk-yuk, you got some toilet paper hanging to your shoe," then sometimes I do wonder why I bother.

I could play this game too and label Mr. Wonk and a few others as stooges for the airlines and their C-suite and investors (particularly Ethiopian which has much to answer for). I'm sure these operators are more than happy to have a few keyboard warriors run cover for them so as not to endanger their supply of cheap pilot labor and even cheaper training. Heck, I imagine it would be quite the return on investment to throw a few bucks/Euro/pesos someone's way to shutdown any possible suggestion that some airlines have honed this practice to a fine art. Yep, that may be the way to go, since that seems to be how some folks around here like to roll.

[Rant on]

So right back at you. Why in the name that all is holy, given all that is known about the decline in training standards and the constant race to the bottom that has defined the piloting profession for the past couple of decades would any of you consider aiding and abetting the conspiracy of manufacturers and operators who find it profitable to arbitrage labor and make minimal investment in training?! Do you actually realize how many people have been hurt or died because some of these businesses can only see as far the quarterly results and can't make the connection between their underinvestment in employees and training and the bent metal and broken bodies?! All's I can say is, "Shame on you!" If you cant' see what's going on, then you are just as guilty as the rest of them!

[Rant off]

So Mr Wonk & others, feel better now that I'm speaking your language, so full of emotion and devoid of facts?

Last edited by yoko1; 4th Jul 2019 at 12:44.
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Old 4th Jul 2019, 12:46
  #1019 (permalink)  
 
Join Date: Apr 2018
Location: Sudbury, Suffolk
Posts: 194
Originally Posted by yoko1 View Post
Do you actually realize how many people have been hurt or died because some of these businesses can only see as far the quarterly results and can't make the connection between their underinvestment in employees and training and the bent metal and broken bodies?! All's I can say is, "Shame on you!" If you cant' see what's going on, then you are just as guilty as the rest of them!
For the record, it was BOEING who decided that no extra training was required in order to fly the MAX.
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Old 4th Jul 2019, 12:57
  #1020 (permalink)  
 
Join Date: May 2010
Location: Boston
Age: 70
Posts: 443
Originally Posted by wonkazoo View Post
Yeah, I could post counter-arguments a mile long but I'm not going to as there is no point. YokoDriver will characterize them once again and we can go round and round for hours but nothing will be accomplished. Further I doubt the veracity, identity and actual animation of the single individual posting under that title- for reasons you identified above. Also (And I don't say this unkindly) if YokoDriver is in fact a lowly air commander of the skies he is (by far) the most verbose, eloquent, and anti-straightforward writing version of that role I have ever seen. Full stop.

It is also clear that the individual(s) posting are not posting for this audience but for another, who may never see PPRuNe until these threads appear in a court case somewhere to show how the "knowledgeable opinions" were all over the place. Sadly many here engage in good faith, thinking that the individual is a single entity and is every bit of what he/she says they are. Thus not a troll in the traditional sense, but nonetheless an individual who feeds on creating division, diversion and hammering home their own core themes, with an overall goal that is not in view of the rest of the forum behind literally every word of every post.

My identity is public. So if I write something objectionable it may impact me personally, which is all you need to really know about the main difference between me and YokoPilot and what weight you should give our respective words.

Warm regards-
dce
(my bold in above)

If Boeing is in fact trying to muddy the waters in a public forum, which may/may not be the case, they are taking a rather unsophisticated approach if the goal is evidence for lawsuits.

As the disclaimer at the top of each subforum states identities are not guaranteed to be anonymous and are subject to legal discovery processes.

If Boeing attempted to introduce PPRuNe content as evidence in a lawsuit you can be sure the other side would be all over discovering the real identity of certain posters.
If these were traceable back to Boeing it would be a devastating bit of evidence.

If there is a corporate effort to influence the discussion I would speculate that it is more aimed at the general press than future lawsuits.

It is also possible that yokodriver is what he claims to be, a passionate pilot with prior professional writing experience with lots of free time for prolific responses.

I have noticed the polished 'debating' style of the responses where irrelevant items are introduced that ignore a clear statement in the post being responded to.
When 'clarified' the response will be further deflection or none at all if the point is obvious.

A good example being my suggestion on revised runaway trim checklist that clearly stated it was not a memory item and -only- the manual electric trim was to be re-enabled,
This was confused by introducing (irrelevant) trim speeds and possibility that wrong side would be re-enabled.

----
I posted this in AM before seeing yoko1 above post so if nothing else there is a clue on his time zone :-)

Last edited by MurphyWasRight; 4th Jul 2019 at 13:02. Reason: Note on morning time.
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