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

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Old 2nd Jun 2019, 09:39
  #121 (permalink)  
 
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Originally Posted by ManaAdaSystem


What issue (NG) would that be? You can’t move the trim wheel manually in the NG sim with the trim fully forward and with strong aft pressure on the yoke. Low speed, high speed, it doesn’t matter.
The issue that the simulator trim wheel forces are lower than in the actual aircraft - so it is not a simulation, and we/most do not know at what stage the manual trim wheel will not be able to be moved ( near full forward or not far past natural, in seconds of a runaway trim). Given the manual trim wheel is hardly used in normal flight, most pilots I expect would be very surprised in the force required to move a moderate out of trim stabiliser. That comment based on known history and recent reductions in trim wheel size - they certainly did not make "it" easier to move!

This was a recent discovery, so your training may not be relevant in a real case of survival incident - but you would pass with flying colours in the simulator.
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Old 2nd Jun 2019, 09:47
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fdr, #116, MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Thank you for the well considered views; interesting challenges.

A solution might require a combination of back-end and front-end fixes.
Adding relatively simple, low risk, minimum certification items at the back, ‘T’ strip, wedge, VGs, could restore the lost ability to move the trim wheel. Also can the severity of a trim runaway be limited (suggestions from other posters), less trim range, new - slower electric trim motor (then requires more, or predictive STS, autopilot issues).
I agree that change is never without risk, flight test surprise, or certification effort, particularly with an already highly modified variant aircraft, which may have less leeway for adjustment.

Front-end change should concentrate on the mechanics. What effect does the smaller trim wheel have, can this be changed, or the lever arm, or gearing be improved.
The human involvement might be the biggest challenge - the expected human contribution in mitigating high risk conditions; recognition, understanding, then choice of action. The accidents have challenged the fundamental beliefs in this area.

I disagree with the notion that the industry can turn the clock back. Even if the new variants are sufficiently similar to the original design, suggesting that trim runaway could be mitigated by training.
Times have changed (part of the problem). Piloting skill levels and range of experiences differ; not lower standards, but a sufficient standard to match the different challenges today, more complexity, more to know, to remember. People (pilots, regulators, manufactures) have not changed, but the conditions in which they work have, possibly with great effect.

shrug it's shoulders’, not to walk away. There is an interesting argument to be made re ‘the greater good’, which could differentiate action between the NG and Max.
After 9/11, reduced air travel resulted in more road deaths because of change of travel method, more than might be expected from aircraft accidents. Thus, NG grounding could be involve greater risk from change in travel than the continued risk in service.
Not so easy for the Max because of the relatively shorter time scale, the accidents, and public knowledge of the Boeing FAA situation - emotional effect. Fix the Max; MCAS done, but trim runaway requires a lot of effort.

We should not expect the FAA to judge a NG and Max split; however, the collective authorities might be able to, being the next best thing to a world opinion short of governmental agreement via ICAO, with political and time scale problems.
But we should not misjudge the fickle public opinion, swayed by media or politically motivated; I doubt a quick resolution in any area
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Old 2nd Jun 2019, 10:02
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Concerns by operators over splits between different national regulators.

https://www.bbc.co.uk/news/business-48489082

It would seem if this has been "leaked", that the recent meeting of regulators over the issue was not conclusive.

If only Dennis Muilenburg was not so obviously beholden principally to Wall Street, leavened only by periodic "our first concern" statements which have all the hallmarks of being written by the legal and PR teams, along with what seem to be somewhat inappropriate and "pushy" statements about the FAA. Come on, Boeing board, we can all see it.
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Old 2nd Jun 2019, 10:22
  #124 (permalink)  
 
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Excellent article by the NYT

https://www.nytimes.com/2019/06/01/b...egister=google
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Old 2nd Jun 2019, 10:23
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Originally Posted by safetypee
There is an interesting argument to be made re ‘the greater good’, which could differentiate action between the NG and Max.
After 9/11, reduced air travel resulted in more road deaths because of change of travel method, more than might be expected from aircraft accidents.

Thus, NG grounding could be involve greater risk from change in travel than the continued risk in service.


Driving deaths and injuries post-9/11
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3233376/

2001-to-2002 changes: fatalities rose by 112, fatal injuries - by 86, incapacitating injuries dropped by 14, "possible or non-incapacitating injury, or injury with severity unknown" dropped by 36.

Total deaths toll rose by (112+86=) 198.

Number of fatalities in LionAir 610 alone was 189. Add ET302, and the number grows to 349.
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Old 2nd Jun 2019, 11:09
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Originally Posted by safetypee

shrug it's shoulders’, not to walk away. There is an interesting argument to be made re ‘the greater good’, which could differentiate action between the NG and Max.
After 9/11, reduced air travel resulted in more road deaths because of change of travel method, more than might be expected from aircraft accidents. Thus, NG grounding could be involve greater risk from change in travel than the continued risk in service.
A number of years ago where I lived had NO SPEED LIMIT, and I regularly travelled at + 100 M/PH (160 K/PH).

Speed limits were then introduced to below 70 M/PH, the first year since the introduction of the speed limits had a very large increase in road fatalities.

Given the current situation/s grounding the NG may not be in the control of FAA and Boeing & that might spread to the other models. The 787 seems to have some other than battery and engine issues, that are being kept very quiet - hush money?
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Old 2nd Jun 2019, 11:23
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Main cause?

With regards to the development and flight testing of the Max I would like to point out that Incompetence and Arrogance is never a good combination.
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Old 2nd Jun 2019, 14:27
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The NYT article is very interesting on so many levels.

Test pilots validating in the sim only? Hopefully, something is lost in translation with the reporters. Makes me wonder if the "tests" Boeing stated it has done have been on the production ac or in the sim?

Also curious, according to the article, MCAS was supposed to use AoA and G force measurements. Unclear if MCAS as implemented included G-force or not.
In going back to the original intent or design of MCAS, does this include the G-force, to my knowledge, this hasnt been mentioned before as part of MCAS.

On flying again, damn...

Clark warned it could take six months to restore operations as other regulators re-examine the U.S. delegation practices - though U.S. majors have only suspended MAX schedules to August.

"That is why it is going to take time to get this aircraft back in the air. If it is in the air by Christmas I'll be surprised - my own view," he told reporters. Emirates' sister carrier flydubai is a major 737 MAX customer.


https://www.yahoo.com/news/2-airline...042835842.html
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Old 2nd Jun 2019, 15:01
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If the NYT article is accurate Boeing found the lower speed stall characteristics of the Max to be unacceptable and prompted them to increase the effect of MCAS by 800% and to initiate the effect at a much lower speed.

The current fix that has been reported reduces MCAS effect back to the originally conceived stab movement rate. Has Boeing indicated how they will solve the lower speed stall characteristics by other means?
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Old 2nd Jun 2019, 15:19
  #130 (permalink)  
 
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Originally Posted by 568
He (Mark) wasn't a "top flight tester" at Boeing.Anyone joining an airline has to join at the FO level due to seniority rules and work up.
According to the article (I know...) this person was responsible for the major redesign of the MCAS system based upon his input. He was also (again according to the article) the point man for FAA documentation on the issue, and if I read it correctly he is the one who convinced the FAA to allow Boeing to remove the mention of MCAS from the flight documents. You cannot convince me that an organization such as Boeing would make such dramatic changes based upon anybody who was not at the top of the flight test food chain.

To be honest I do find the sequence described in the article a little hard to believe; they imply that it was test that came up with the engineering solution which is pretty rare in my experience, but I don't work with aircraft. I feel that there is a goat named "Scape" somewhere in this story.
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Old 2nd Jun 2019, 15:49
  #131 (permalink)  
 
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Originally Posted by ProPax
If this whole unmovable trim wheel kerfuffle plays out to its full potential, Boeing is staring down the barrel of BOTH MAX and NG being grounded. And that might very well be the end not only for the 737, but for the Boeing Company. I'm not even sure their military division will be able to bail them out, unless they quickly disconnect the two parts but that would require a shareholders meeting which won't be quick. (Correct me if I'm wrong.)

So, just hypothetically, wouldn't it be safer for Boeing to simply close the 737MAX program, cut their losses, buy back the MAXes and try to cuddle the FAA into stopping the NG trim wheel inquiries? They could then concentrate on NSA, or NMA, or MOM, or whatever it is they want to do. They would likely come out of this way behind Airbus in sales and customer trust, and will have to fight back into that market, AND they have very little experience in that kind of marketing. It will be a HUGE loss and an enormous effort. But, IMHO, it's the lesser evil. The more this drags on, the less likely Boeing is to come out of this alive. As much as I like Airbus, I don't want them to be an unopposed monopolist.
I've basically asked this same question before: At what point does this become a dead horse they're flogging here? And the deader it gets, the worse it smells. And the worse the PR.

Unfortunately it apparently goes beyond the 737. My apologies if this 48-minute documentary has been posted before -- if so, I missed it. It was published several years before the MAX began delivery and has to do with the 787. But what it's really about is Boeing management these days. (And yes, a Boeing / Airbus duopoly is preferable to an Airbus monopoly.)

What do I know? Perhaps Boeing has just been lucky with the 787. Or could it be that fasteners hammered home any-old-how by drug-addled employees under deadline pressure require dozens of thousands of hours and cycles before they finally fail, having maybe escaped detection in D-checks? But when a 32-year veteran Boeing engineer says she wouldn't fly on the 787, that has to mean Something.

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Old 2nd Jun 2019, 17:12
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The view from outside looking in: Boeing needs to start over, design a new clean slate single aisle. All this fussing around on how to thread this needle is wasted effort, lipstick on a pig.

I, and I suspect most of the public, still have a foundation of trust toward Boeing, even after how the 787 launch occurred, for everything up to the MAX, but how they handle this could erase it all.

Down playing anything= trust gone. Blaming anyone outside Boeing= trust gone.

(What gobsmacks me most about the NYT article is how casually MCAS came into existence, and how casually it was implemented.)

If Boeing did their strategy right, the MAX is a neutralization innovation in the market, intended to level the playing field in the short term, which only works if they simultaneously started development of a disruptive offering, a new clean slate single aisle. So they should be only 2-4 years away from launching that new one, right?
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Old 2nd Jun 2019, 17:41
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SLF, engineer and ex-college teacher here.

Based on the NYT article, it appears Boeing has "technical pilots" who write checklists, manuals and instructional materials. But the accountants at Boeing barred these "technical pilots" at Boeing from flying (did they keep their licenses current?) and so the "technical pilots" based the Max instruction manuals they wrote on the NG-derived sims, which of course do not evidence the significant force necessary to manually trim using the small NG trim wheels, especially at speed.

This is going to go down in the annals of computer simulation methodolgy as a textbook teaching case of method failure, reliability engineers breathing their own exhaust and considering their own simulator as a valid replacement for the physical thing for safety validation. The unfortunate fact is that both Boeing and the FAA should have a technical process in place for ensuring that emergency checklists and procedures are validated against the real thing and not just the sim. My own feeling is that every list important enough to be memorised should be checked in the air. The fact the FAA did not do this for certification means that it will now be necessary to go over all the Max and possibly even NG checklists with a fine tooth comb to look for other cases where the real world might -so very inconveniently- diverge from a well-behaved simulation.

The farce is now such that one does wonder where incompetence stops and full-bleed corruption has taken over. Even the NYT clearly smells a dead rodent.

Edmund
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Old 2nd Jun 2019, 18:00
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Could someone please explain what is the difference between "test pilot" and "technical pilot"?
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Old 2nd Jun 2019, 18:05
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Originally Posted by Smythe
article from NYT on the foundation of MCAS...very interesting

https://www.nytimes.com/2019/06/01/b...max-crash.html
wow, if this article is correct, MCAS _is_ an anti-stall system. That changes everything. It’s a system designed on purpose to continously trim down based on a single aoa input _to prevent stall_.
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Old 2nd Jun 2019, 19:07
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From Job announcement SEP 2017: (this is the Chief position, so...a qual as a Cpt)

747 Chief Technical Pilot

Boeing Commercial Airplanes (BCA) has an exciting and unique opportunity for a 747 Chief Technical Pilot to join our Commercial Aviation Services team.
This team support a variety of training and flight services for commercial airplanes and their customers around the world.
As a Chief Technical Pilot you will perform as a chief technical consultant on the 747. In this role you will provide flight operations, safety and technical support to Boeing internal and external customers at multiple levels. While this role is not primarily a flying job, the selected applicant will still maintain qualification as a Boeing Captain on at least one aircraft model.
Other responsibilities include:
  • Supports new aircraft and system development and certification efforts.
  • Develops and validates procedures and operating techniques and assists other Technical Pilots with cross-model procedures.
  • Provides information and specialized technical services to Company and customer flight crews to enhance flight operation efficiency.
  • Consults with cross-functional teams during accident investigations and analysis as needed.
  • Researches, edits, documents and coordinates publication of procedures and techniques for operating Boeing aircraft.
  • Represents Boeing as a technical lead by authoring and presenting professional papers at worldwide safety and flight operational forums.
  • Meets with regulatory agencies at the executive level.
  • Supports sales campaigns by discussing and demonstrating airpcraft and new flight technology.
  • Serves as a consultant to senior management and other industry professionals.
  • Works under minimal direction.
Test Pilot, well, that is the flying position.

FAA Test Pilot job announcement:

Flight Test Pilot (FTP) with primary responsibilities to ensure type certification of the performance, stability, and control requirements including envelope expansion, handling qualities and performance of new or modified Title 14, Code of Federal Regulations (CFR) Part 23 and/or Part 25 aircraft.

Incumbent serves as a Flight Test Pilot (FTP) with primary responsibilities to ensure type certification of the performance, stability, and control requirements including envelope expansion, handling qualities and performance of new or modified Title 14, Code of Federal Regulations (CFR) Part 23 and/or Part 25 aircraft.

Responsible for the flight test compliance of the type certification processes for avionics, propulsion, and mechanical/electrical systems and equipment installations on those same aircraft.

The FTP conducts qualitative and quantitative flight tests and evaluates engineering data on modified and new type design aircraft to oversee and spot-check applicants' compliance showings for applicable airworthiness requirements.

The FTP also applies expertise and experience to recommend improvements to internal/external processes related to certification and organizational issues.



In my organisation, we have plenty of technical pilots who only have the college degree, with no actual experience flying a commercial aircraft. They get typed in the sim, that is about the extent of it for most.

Usually they are working the sim on the RNAV/VNAV procedures to check for any issues, temperature limits, weight limited OEI procedures, and especially temporary obstacles. (ie verifying NOTAMs)

There are levels where the ATP and 1500 hrs is the minimum...that being said, even with those quals, it is not a flying position.

Last edited by Smythe; 2nd Jun 2019 at 19:28.
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Old 2nd Jun 2019, 21:48
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The following story popped up in my news feed: https://www.reuters.com/article/us-b...-idUSKCN1T30RX
The U.S. Federal Aviation Administration said on Sunday some Boeing Co 737 MAX and NG planes may have parts that were improperly manufactured and that it will require their replacement
The FAA said up to 148 leading edge slat tracks manufactured by a Boeing sub-tier supplier are affected and cover 133 NG and 179 MAX aircraft worldwide.
Edit: Sorry, only quoted the first part of the story:
Boeing, the world’s largest plane maker, said it has identified 20 737 MAX airplanes most likely to have the faulty parts and that airlines will check an additional 159 MAXs for these parts.
Boeing said one batch of slat tracks with specific lot numbers produced by a supplier was found to have a “potential nonconformance” and said airlines “are to replace them with new ones before returning the airplane to service.”
Edit: Parallel thread created around the same time as my post: Boeing notifies FAA that parts in Max and other 737s may be ‘susceptible to premature

Last edited by GordonR_Cape; 3rd Jun 2019 at 07:44.
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Old 2nd Jun 2019, 22:09
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Oh, joy! How long does it take the MTX to replace the slats, per aircraft?
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Old 2nd Jun 2019, 23:07
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Originally Posted by ProPax
Oh, joy! How long does it take the MTX to replace the slats, per aircraft?
On the bright side, replacing parts won't impact revenue from the MAX.

Edmund
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Old 2nd Jun 2019, 23:28
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Originally Posted by edmundronald
On the bright side, replacing parts won't impact revenue from the MAX.

Edmund
exactly the issue, every AD will make the news, even though there have always been many, the public didn't know (or cared)
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