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737 max returning to service ?

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737 max returning to service ?

Old 6th May 2019, 07:32
  #121 (permalink)  
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Originally Posted by slacktide
Is that fact, or is it your opinion, or is it someone else's opinion? Do you have any documentation of this that you can share?
Dave The Rhino writes clearly. The second sentence of 25.203(a) would be a sticking point with the design as disclosed to date, 25.173 is more general in scope. The disclosed logic indicates that the problem arises in turning stalls, but the permissible pitch characteristics is in paragraph (a), and MCAS is definitely working in that area. That particular sentence is the reason for having stick pushers in some designs, most often T tail aircraft. In the normal course of affairs, this would occur around stick shaker so would not be readily observed by a pilot, there is enough happening to keep them busy at that point. That makes some sense as to why the OEM went that way, Adding a stick pusher would have been a notable change to the design, and stick pushers have the same capability of giving an out of trim condition unless deactivated.

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Old 6th May 2019, 08:35
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Originally Posted by fdr
er, nope, it doesn't do that. It may be semantics but the 2.5 degrees is not an attitude value, it is the shift of the trimmable horizontal stabiliser, THS by a maximum value of 2.5 degrees Aircraft Nose Down, AND, which is also stabiliser leading edge down, which will give whatever to the aircraft attitude, dependent on what the driver does on the control column. MCAS is an input for control force, it is not a pitch attitude adjusting system, of course left unchecked it apparently is good for about 40 degrees nose down...
It changes the feel by changing the pitch of the whole plane. Which is a weird way to change the feel of the control column. Change the attitude of the whole plane.
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Old 6th May 2019, 15:47
  #123 (permalink)  
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Originally Posted by RickNRoll
It changes the feel by changing the pitch of the whole plane. Which is a weird way to change the feel of the control column. Change the attitude of the whole plane.
Not really; recall that the system is functional only in manual flight, which is when the pilot is in the control loop. The pilots task is to fly the aircraft to an attitude that gives the performance that is desired. With normal, compliant control characteristics, static stability results in an aircraft that wants to revert to trim speed (AOA) and so if below the trim speed, it will want to pitch down, which is countered by a pull force from the pilot to obtain an off trim speed condition that the pilot desires. That is exactly the same situation that occurs with MCAS, ll it is doing is exacerbating the off trim speed margin so that the desired force profile is achieved. With the information on the area of 203(a) that also indicates that the tendency for a reduction in stick force approaching an accelerated stall is offset by the nose down trim. If the pilot wants to fly at that AOA, he can, the force will be appropriate for a naturally compliant system. Arguably it is also similar in outcome to a stick pusher, except that it has input to the trim over time, not a direct and prompt push on the elevator. Stick pushers are pretty savage in their response compared to the initial triggering response of MCAS.
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Old 6th May 2019, 16:39
  #124 (permalink)  
 
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fdr is right.
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Old 6th May 2019, 17:30
  #125 (permalink)  
 
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Originally Posted by Bergerie1
fdr is right.
Apart from the

Originally Posted by fdr
Aircraft Nose Down, AND, which is also stabiliser leading edge down
bit.
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Old 6th May 2019, 17:34
  #126 (permalink)  
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Talking

Originally Posted by DaveReidUK
Apart from the



bit.
oops, my mistake, long day, that is so, AND is stab LE up. Going back to sleep.
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Old 6th May 2019, 19:26
  #127 (permalink)  
 
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Originally Posted by SMT Member
Simulators are indeed few and far between, but on the other hand there are +400 frames standing idle on the ground, why not bring them to use? Sure, it costs a hell of a lot more than using a sim, but, using them will reduce the time needed to get all crews trained.

So, how about we have Boeing trainers train the airline TRI/TREs in the real aircraft, and then have the TRI/TREs train the TCs in their grounded fleet, who in turn may train the line pilots, either in real aircraft or in simulators as available.
What a great idea! On top of everything, to assure the maximum chance of this unorthodox scheme's success, first batch of the program's pilots should be volunteers with unwavering faith in Boeing. I suggest using PPRuNe posts professing belief that there's nothing much wrong with the MAX, just with the pilots, as an initial method of fishing out such distinguished airmen.

Originally Posted by EDML
Hmm, after the outcome of two out of three MCAS failures it might not be a wise thing to train that very problem in the real aircraft.
Depending on who you send up first.

Originally Posted by RetiredBA/BY
You would have been flying empty aircraft !
Not necessarily, there are plenty of non-pilot types around PPRuNe threads dealing with B-MAX, professing their belief in Boeing's finest narrowbody. We could send 'em up as safety observers.

Originally Posted by BluSdUp
Lets hope the we do not have to fish a Max out of the Mediterranean the next few years.
I do not think that MAX will have to be fished out of anything in the next few years but I would really like to know if there's any significant difference between fishing the aeroplane out of the Mediterranean and the Java Sea?

Originally Posted by RetiredBA/BY
Many years ago I was posted to an RAF squadron as a replacement pilot for one killed in the Valiant crash believed to have been caused by a runaway stab. The aircraft were not modified BUT we all went into the sim to practice the recovery procedure as it was found that full elevator could just overcome the stab. Deflection. Boeing please note.
I guess that you're familiar with 737 preMAX FCTM claim that it can be flown and landed with stabilizer in any position.

Well, "flown" part probably requires further qualification. Excessive Vee squared might get in a way at the extremes of the stabilizer deflection.

Interweb posting boards are full of superpilots who faced with simultaneous continual trim, stickshaker and airspeed discrepancy would have cut the trim switches and reduced speed. Thank FSM for the proliferation of good quality training and flying folks who are not inhibited by modesty to admit they 'ave received one.

Originally Posted by laxman
Reading through these posts has been painful for this MAX qualified pilot but since this is a public board, and many non-fliers are making comments and contributions that defy reason and logic, that are coming from an emotional basis, and one not based upon any experience or knowledge, I should not be surprised.
Dude, as a MAX qualified pilot (hey, up to grounding, as an 738 capt, I was lawfully required just to have a look at a couple of PPTs in order to act as a fully qualified commander on revenue MAX flight, no previous sim or line instruction needed) I deeply sympathize with your plight. However, as someone acquainted with the works of McRaney, Milgram, Fromm, Reich, Arendt et. al. I'm not in the very least surprised by the brand loyalty displayed on the MAX topics. Since it's only anonymous bulletin board affecting almost nothing, I don't find it disturbing, just mildly amusing.
Originally Posted by John Marsh
How do today's airline pilots compare with those of 1980?
Severe statistical improvement of civil transport aviation safety in last couple of decades is not only due to improvement of today's airline pilots performance but it would definitively have been impossible without one.
Originally Posted by John Marsh
If there has been a downward trend in competence in non-normal situations, has Boeing tailored its design philosophy to suit?
Such a trend has not been widely observed outside fear-mongering (mostly anonymous) rants.
Originally Posted by John Marsh
How reasonable is it to expect Boeing to be able to make such an adjustment?
I'd estimate reasonableness of such an expectation to be poor to nil.
Originally Posted by Kerosene Kraut
If authorities require heavier stick feel close to the stall for certification why not modify the feel system instead of violently interfering with the steering and using the trim to brute force the nose down?
My totally unqualified guess would be because it was cheaper this way.

Originally Posted by yanrair
I have been surprised by the lack of comment from those who actually fly the Max but presumed they were keeping their heads down.
I find the lack of recent flying experience on MAXes extremely unsurprising.

Originally Posted by fdr
Adding a stick pusher would have been a notable change to the design, and stick pushers have the same capability of giving an out of trim condition unless deactivated.
No!

They do not have anything to do with the trim! They act on elevators!

David Petit Davies' deathless tract is still very much relevant 52 years after the first publication and 48 years after the last revision... and still quite misunderstood. Pages 130 onward apply. It is pretty clear that any stick pusher has to be designed so it can be manually overridden if it is activated unduly. Colgan 3407 is a case in point; pusher activation was really needed, yet the panicked pilot kept pulling ,overriding pusher, and stalled the aeroplane. Data from the catastrophes of PK-LPQ and ET-AVJ are still sketchy, but what little has leaked strongly suggests inability to stop pitch down with control column alone.
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Old 7th May 2019, 11:00
  #128 (permalink)  
 
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Originally Posted by Clandestino
My totally unqualified guess would be because it was cheaper this way.
MCAS is an extension of the existing STS. Very cheap to implement.
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Old 7th May 2019, 14:23
  #129 (permalink)  
 
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Air Canada using its 2 MAX sims to model accident scenarios

Air Canada CEO Calin Rovinsecu quoted in Toronto Globe and Mail yesterday: "Mr. Rovinescu said it could take several weeks to fully deploy the 737 Max once it is cleared by regulators. But because Air Canada is the only airline in Canada or the United States with a 737 Max simulator (it has two in Toronto), its pilots are “modelling some of the scenarios that occurred in the two accidents. So that has given us a leg up in terms of the readiness for the pilots to go back into flying these aircraft.”

Hmmm. 400+ AC MAX pilots. MAX grounded since March 19. 2 sims. A lot of learning.....
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Old 7th May 2019, 14:30
  #130 (permalink)  
 
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Originally Posted by RickNRoll
MCAS is an extension of the existing STS. Very cheap to implement.
Not only that, it already existed (albeit for slightly different design purpose) on the KC-46. All they had to do was rip it off there, remove the redundant AOA inputs and make it just work off one (can't have it depend on two on 737 because then FAA will mandate Sim training) and also remove the aft column cutout switch so it will still trim down even when the pilot is pulling up. Then when flight tests show your aero modelling was deficient, make it four times more powerful to compensate.

Job done, plane certified. Cease panic. Aaaaannnnd breathe. Now quietly collect bonus and run before the st starts throwing itself out of the sky...
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Old 7th May 2019, 16:37
  #131 (permalink)  
 
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Boeing Stock is down $9.62, that's 2.6%, in first 2 hours of trading.
This bird is not going to fly for a very long time.
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Old 7th May 2019, 16:49
  #132 (permalink)  
 
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Originally Posted by Sultan Ismail
Boeing Stock is down $9.62, that's 2.6%, in first 2 hours of trading.
This bird is not going to fly for a very long time.
The markets are down generally and 2.6% isn't excessive.

More to do with US / China trade tensions than anything else:

Stocks on Wall Street have continued to lose ground on Tuesday, and European markets - which were already lower - have fallen further since US trading began.
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Old 7th May 2019, 18:50
  #133 (permalink)  
 
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Interesting, Air Canada said they have 420 pilots idle due to the MAX grounding. The have 24 MAX.
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Old 7th May 2019, 21:55
  #134 (permalink)  
 
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They were supposed to have 36 by the end of this year with more to come. So it seems they were front-running their training requirements with that many pilots. It typically takes around ten pilots per plane plus trainers and fleet management adding to the numbers. Air Canada doesn’t operate NGs so I guess Boeing will be paying some legacy pilot salaries for awhile.
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Old 7th May 2019, 22:12
  #135 (permalink)  
 
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Air Canada MAX pilots

The Globe & Mail news article also said:

<<Calin Rovinescu, Air Canada’s [CEO], said the company has about 425 Max pilots who are spending their days training on a 737 Max simulator, but not flying customers. Some pilots who flew other planes in the past year – narrow-body Airbus or the Embraer 190 – will return to flying those models, [he] said.>> and <<because Air Canada is the only airline in Canada or the United States with a 737 Max simulator (it has two in Toronto), its pilots are “modelling some of the scenarios that occurred in the two accidents. So that has given us a leg up in terms of the readiness for the pilots to go back into flying these aircraft.”>>

https://www.theglobeandmail.com/busi...ing-of-boeing/
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Old 8th May 2019, 06:46
  #136 (permalink)  
 
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Originally Posted by boaclhryul
The Globe & Mail news article also said:

<<Calin Rovinescu, Air Canada’s [CEO], said the company has about 425 Max pilots who are spending their days training on a 737 Max simulator, but not flying customers. Some pilots who flew other planes in the past year – narrow-body Airbus or the Embraer 190 – will return to flying those models, [he] said.>> and <<because Air Canada is the only airline in Canada or the United States with a 737 Max simulator (it has two in Toronto), its pilots are “modelling some of the scenarios that occurred in the two accidents. So that has given us a leg up in terms of the readiness for the pilots to go back into flying these aircraft.”>>

https://www.theglobeandmail.com/busi...ing-of-boeing/
Bravo on the timely housekeeping.

Unless of course it’s akin to making beds in a burning house!

Last edited by KRUSTY 34; 8th May 2019 at 11:31.
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Old 8th May 2019, 06:53
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This is a good article on Boeing certification problems:

https://www.seattletimes.com/busines...uding-737-max/

Fly SAFE!

God Bless, and Namaste...
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Old 8th May 2019, 13:24
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Another take on Boeing's culture problem....

RichardAboulafia.com

Dear Fellow Company Anthropologists,

To my deep regret, my only personal contact with Herb Kelleher, the great founder of Southwest Airlines who died in January, was, predictably, over a drink in a bar. As for any aviation fan, that moment made my list of career highlights, and indeed life highlights. Not only was he a remarkable character who helped reinvent the industry, he also provided what may be the best management quote ever: “Your employees come first. And if you treat your employees right, guess what? Your customers come back, and that makes your shareholders happy. Start with employees and the rest follows from that.” This was not only a humane vision of the world; it was also a great maxim for long-term company success.

Boeing really needs to learn from Herb. That’s the big lesson I can provide after 30+ years of following the company, and after spending the past months, like everyone else in the industry, studying the two 737MAX8 disasters and the subsequent groundings. The likeliest explanation for the design mis-steps that contributed to (but were not solely responsible for) these two crashes relates to company culture, and how Boeing values its employees, particularly engineers.

First, a few words in support of the 737MAX, against the mass of misinformation out there. This was the right product to launch. Boeing was not being greedy, desperate, or short-sighted; rather, there was no business case for a clean-sheet design. I advocated for it at the time, as did many others (see my July 2011 letter). And it was not a rushed job; six years is a lavish amount of time to allow for a derivative jetliner. The result is a good jet, but one with a problem. As Bank of America/Merrill Lynch analyst Ron Epstein told me, “It’s not a flawed product. It’s a good product with a flaw inserted inside it.”

But about that flaw. There were many causes of the two crashes, but MCAS connects them. And under examination, the design and integration of the MCAS looks shoddy. There are valid questions about the training requirements associated with its introduction, too. One upside: fixing the MAX isn’t a major technical challenge. The mistakes are too obvious to not be easily fixable.

As Epstein asked on Boeing’s earnings call this month, “How did this happen?” First, it wasn’t about money.There is no significant economic difference between doing MAX with a perfectly fine stall avoidance system and doing it with MCAS. The R&D budget for MAX was quite adequate. And it wasn’t about time – again, they gave it six years, so there’s no evidence at all that this was rushed.

That really just leaves one possibility: company culture. And there’s a lot to go on here. Like others, I’ve been writing about the rift at Boeing between engineering and management for decades (see my June 2002 letter). But during the key years of MAX development, things got toxic. If you want to keep reading, see my September 2014 and January 2013 letters. But to summarize, company management made a concerted effort to cut labor costs and to destroy labor’s bargaining power. Pensions were eliminated, and benefits cut.

Machinists were the primary target of the contract re-negotiations, which helps explain the recent spate of stories about production line issues on the 787 and KC-46, and the associated whistleblower allegations. But engineers were hit too. More importantly, the engineers were also marginalized, from a management perspective. The BCA president who launched the MAX left the company, and his replacement, in charge of the development phase, did not have an engineering degree. Neither did the company CEO, so you had an aerospace engineering company led completely by non-engineers. That company CEO, Jim McNerney, also bragged about his ability to make employees cower. Somehow, the two found a way to get through the 787 battery crisis by relying on the hard work of others, and perhaps not fully understanding what those others needed to do.

The big question: Was this dynamic a key factor behind the mistakes that led to MCAS? If so, how did that play out? First, in the absence of any other likely causes behind the MCAS debacle, this might be the right place to look. Second, it might have been an issue of empowerment and communications. This alignment of non-engineers, particularly when the CEO had a notoriously imperial style, could not have been good from the standpoint of correctly allocating resources, and most of all, listening to any concerns by engineers. Delivering bad news was generally regarded as a very bad career move, which explains why the CEO wasn’t told that the Dreamliner rolled out on 7-8-07 wouldn’t be ready to fly for another year.

In the backdrop of those labor problems Boeing enjoyed unprecedented prosperity, and was creating a seemingly unstoppable financial juggernaut, purely for the benefit of investors. In 2012, 19% of operating cash flow was given out in the form of shareholder dividends and buybacks. By 2015, the last year of McNerney’s reign as CEO, this had risen to 99%, or $9.3 billion in dividends and buybacks. McNerney’s salary skyrocketed, hitting $29 million in 2014.

The percentage of cash flow given to investors has since gone down, but the absolute amount has risen (2018 saw 84% returned, but a record amount of $12.6 billion). If there was a race to give away cash in the jetliner business, Boeing certainly won. Per Bank of America/Merrill Lynch, “Boeing has materially outperformed Airbus on capital return over the last 15 years, returning $78bn of capital to shareholders, vs. Airbus returning €11bn through dividends and buybacks.”

This juxtaposition of disgruntled labor and record shareholder rewards was basically a recipe for a rift between management and the people responsible to creating aircraft. And it was a perfect reversal of Kelleher’s maxim. Share price was obsessed over. Customers came second. Company assets, such as people, became a commodity, something to be measured against returns.

Has Boeing changed since those awful years of toxicity, the very years of MAX development? Can it continue to recover from those bad old days? Thankfully, both the head of BCA and Boeing now have engineering degrees, and there does seem to be a better approach to labor. People I speak with at Boeing seem a lot less angry than they did then (although there’s still plenty of anger out there). On the other hand, this month, CEO Dennis Muilenburg asked the board “to establish a committee to review our company-wide policies and processes for the design and development of the airplanes we build,” and somehow, as Ron Epstein noted, they created a committee without a single engineer.

And there’s also this conundrum: Management is addicted to growing the company’s share price, and investors are hooked. In February 2016 the was at a five year low of $109. Just before the second crash, it peaked at $446, and has stayed in the $375-380 range. So, as long as the share price stays reasonably high, there’s not much reason to think anything will change. And Boeing will be fine. Until the next crisis.

Yours, ‘Til President Trump Demands That Boeing Rename Itself,

Richard Aboulafia

​​​​​​Richard Aboulafia is Vice President, Analysis at Teal Group. He manages consulting projects for clients in the commercial and military aircraft field, and has advised numerous aerospace companies. He also writes and edits Teal's World Military and Civil Aircraft Briefing, a forecasting tool covering over 135 aircraft programs and markets.
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Old 8th May 2019, 13:49
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The other threads have been closed due to lack of information, but perhaps this is the critical point in getting the 737 Max back in service.
There still is no clarity as to what exactly contributed to the incorrect value of AoA. There has been speculation about vane hardware, broken vane, signal conversion, and digital glitches, but none have been shown to be consistent with interpretations of the FDR across both accidents - even if they need to be.

If the problem is with the vane, then how might this effect other aircraft - in service inspections; conversely without problems, the vane manufacturer could publicly declare that it is not a contributing factor (but in either way they might be respecting the confidentiality of the investigation).
How many vane units have been found, in what condition.

The difficulty with electrics or software is that they rarely leave ‘witness marks’. If electrical shorting due to damaged cables, then no fleet-wide inspections so far. Why left side only.
Would software issues be just chance, random; at face value an unbelievable coincidence. (Yet I still buy my lottery ticket).

How can the regulators accept that a modified system provides sufficient defence against a further event if the ‘root’ of the problem is not know / not repeatable. Perhaps the regulatory process will also revert to probability.

If the two investigations are suffering similar difficulties, then the return to service date might depend on publication of the investigation findings.
But what if the findings are inconclusive, or differ. (Worth the price of a lottery ticket)




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Old 8th May 2019, 14:37
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damn, that is quite the explanation from Aboulafia..

On the other hand, this month, CEO Dennis Muilenburg asked the board “to establish a committee to review our company-wide policies and processes for the design and development of the airplanes we build,” and somehow, as Ron Epstein noted, they created a committee without a single engineer.

Lesson NOT learned...
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