MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
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From a presentation of 2019-09-03 by EASA's Executive Director Patrick KY, as posted on the European Parliament's website:
IMHO, "Too high forces needed to move the manual trim wheel in case of a stabiliser runaway" is technically challenging. I can't see an easy fix. At best, software can make stabilizer runaway extremely unlikely. Training can improve recovery to a degree (see the Boeing advice on "aerodynamically relieving airloads" using manual stabilizer trim thread), but subject to altitude constraints.
IMHO, "Too high forces needed to move the manual trim wheel in case of a stabiliser runaway" is technically challenging. I can't see an easy fix. At best, software can make stabilizer runaway extremely unlikely. Training can improve recovery to a degree (see the Boeing advice on "aerodynamically relieving airloads" using manual stabilizer trim thread), but subject to altitude constraints.
Last edited by fgrieu; 6th Sep 2019 at 16:16. Reason: fix link
# 2225
The fourth item could also be challenging;
It can be assumed that MCAS is now well protected from a single AoA failure, but the coincident effects on other systems - ADC, speed corrections, Stick Shake, EFIS low speed awareness, are unacceptable during takeoff given the likely failure rate of the AoA input (accident history / investigation).
Why did the AoA fail at or before takeoff in the two accidents and not later in the flights?
A failure in a dual AoA system can be detected by comparison, and the disagreement alerted, but a correct value cannot be identified, which other systems could switch to. Hence rumoured requirement for a triple AoA system - or a much higher reliability sensor.
Similarly for flight without MCAS, which could be acceptable for rare occurrences, but if the AoA reliability was low then this too could be unacceptable for certification.
The fourth item could also be challenging;
It can be assumed that MCAS is now well protected from a single AoA failure, but the coincident effects on other systems - ADC, speed corrections, Stick Shake, EFIS low speed awareness, are unacceptable during takeoff given the likely failure rate of the AoA input (accident history / investigation).
Why did the AoA fail at or before takeoff in the two accidents and not later in the flights?
A failure in a dual AoA system can be detected by comparison, and the disagreement alerted, but a correct value cannot be identified, which other systems could switch to. Hence rumoured requirement for a triple AoA system - or a much higher reliability sensor.
Similarly for flight without MCAS, which could be acceptable for rare occurrences, but if the AoA reliability was low then this too could be unacceptable for certification.
Thanks fgrieu... one can't begin to wonder if the MAX return to service is going to happen before Summer 2020...
Another interesting thing in that EASA document is where they propose ECO-Labels on aircraft, like on your household appliances, washers and dryers...
Another interesting thing in that EASA document is where they propose ECO-Labels on aircraft, like on your household appliances, washers and dryers...
And of course you try to build what the customer wants. I read elsewhere that SWA wasn't really interested if it was going to take significant retraining/resources (may as well buy a different aircraft then). So if your primary customer wants something you try mighty hard to give it to them. At the same time SWA said sure we'll buy them under that scenario, but for us to commit we need some assurance you won't change the goal later, hence the $1 million incentive.
Sometimes you win such a gamble, sometimes not. Here, in the end, Boeing did not. Neither did SWA.
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Wow!
”No delegation to FAA” That is harsh! The FAA must be feeling like Boris Johnson after his brother resigned, to put the national interest above friendship with his brother.
I can only assume that this stance has been taken after EASA failed to reach a unified approach to the recertification. Something tells me that Boeing and the FAA are going to have to compromise on the sim time requirements at the very least.That will pose some contractual difficulties for Boeing as I assume that the ‘iPad only’ conversion was written into the purchasing agreements.
And condition #2 is so open ended as to be meaningless.
Edmund
I don't think that anyone in Boeing or the FAA understands the damage done to both their reputations by self certification.
The actions of EASA (in particular) may just be a reminder to the USA that the FAA is not the sole certifying agency. One wonders when Canada and China are going to follow suit
The actions of EASA (in particular) may just be a reminder to the USA that the FAA is not the sole certifying agency. One wonders when Canada and China are going to follow suit
I understand why EASA is now so strict, they have to be this way. But separating authorities and certification again is the wrong way to go.
We need a bullet proof trustworthy system again. Where everybody can rely on each other. Better bring back the trust again and change everything that's in between.
EASA is not fighting Boeing or anybody else but they must be sure that no interference with the industry takes place (again). We need a united approach to bring it back to flight not a patchwork world. A robust, proven and flight demonstrated modification will be the beginning.
We need a bullet proof trustworthy system again. Where everybody can rely on each other. Better bring back the trust again and change everything that's in between.
EASA is not fighting Boeing or anybody else but they must be sure that no interference with the industry takes place (again). We need a united approach to bring it back to flight not a patchwork world. A robust, proven and flight demonstrated modification will be the beginning.
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Teachers don’t get the kids to mark their own homework. The same should apply here.
3. Accidents of JT610 and ET302 are deemed sufficiently understood.
I am guessing EASA want the final reports out to review, before they guess what needs to be addressed. They would not want to commit only to get embarrassed by an oversight, by something in one of the two reports yet to be released.
I am guessing EASA want the final reports out to review, before they guess what needs to be addressed. They would not want to commit only to get embarrassed by an oversight, by something in one of the two reports yet to be released.
Seems the 777X also has some issues.
Seattle radio KOMO reports the aircraft had a door pop off during extreme pressurization testing, with FAA officials watching.
https://twitter.com/hashtag/KOMONews?src=hashtag_click
Perhaps merely something misrigged, but Boeing historically uses plug type doors, so perhaps something more serious.
Seattle radio KOMO reports the aircraft had a door pop off during extreme pressurization testing, with FAA officials watching.
https://twitter.com/hashtag/KOMONews?src=hashtag_click
Perhaps merely something misrigged, but Boeing historically uses plug type doors, so perhaps something more serious.
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Further reporting on KOMO now that the final test where they bend the wing to failure failed.
https://komonews.com/news/local/door...ng-stress-test
https://komonews.com/news/local/door...ng-stress-test
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And the first step must be an end to the FAA’s Designated Representative system.
Possibly, aircraft were issued a design approval with a flaw, by a designee, and unfortunate crashes can be attributed to that. Has a pilot, who has been issued a license by a designated examiner, ever caused an accident? Has there been a call to return all pilot examinations to staff of the authority?
a) a injury prevention method.
b) a death prevention method
c) a regulatory requirement.
D) ALL of the above!!!!!!!!!!!!
MCAS is only a regulatory requirement - none of the others were required when MCAS was developed and redeveloped.
Stick to the story - stalls never happen at high AoA and never would a lighter stick force, at a high AoA lead to even one unintentional stall - ever.
EASA need not wait for both accident reports but will I imagine wait for Indonesian report on JT 610. It’s due next month.
ICAO Annex 13 requires that State conducting investigation make Final Report publicly available “if possible” within twelve months. If not, State shall make an interim statement on each anniversary of the occurrence, detailing progress and any safety issues identified.
I expect the report to be just as timely, professional and non-judgemental as Indonesia’s report on Air Asia A320 flight QZ8501 - https://www.bea.aero/uploads/tx_elyd...XC-reduite.pdf. Indeed some aspects will be depressingly similar; defect reporting, maintenance, startle/CRM.
ICAO Annex 13 requires that State conducting investigation make Final Report publicly available “if possible” within twelve months. If not, State shall make an interim statement on each anniversary of the occurrence, detailing progress and any safety issues identified.
I expect the report to be just as timely, professional and non-judgemental as Indonesia’s report on Air Asia A320 flight QZ8501 - https://www.bea.aero/uploads/tx_elyd...XC-reduite.pdf. Indeed some aspects will be depressingly similar; defect reporting, maintenance, startle/CRM.
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A very unfortunate side effect of this debacle is that Boeing have put themselves into play in world trade tensions. Whereas before the different FAAs all had mutual recognition agreements, at a time of Trump inspired trade wars Boeing has made themselves into the ball that will be kicked up and down the muddy pitch until it is bent out of all shape. And all to save a few hundred million dollars and undo decades of superb engineering. It's hard to think of a bigger self-inflicted injury. The entire 737 management team at B would resign out of honour if they were Japanese.
G
G
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Story just came to my attention. Link may be paywalled: https://www.seattletimes.com/busines...nt-protection/
Edit: Previously published article: https://www.nytimes.com/2019/06/01/b...max-crash.html
A former Boeing official who played a key role in the development of the 737 MAX has refused to provide documents sought by federal prosecutors investigating two fatal crashes of the jetliner, citing his Fifth Amendment right against self-incrimination, according to a person familiar with the matter
Mark Forkner, Boeing’s chief technical pilot on the MAX project, invoked the privilege in response to a grand jury subpoena issued by U.S. Justice Department prosecutors looking into the design and certification of the plane, the person said.
Invoking the Fifth to avoid testifying, while a legal right, is sometimes interpreted as an admission of guilt. Its use to resist a subpoena for documents is less common and may only imply a dance between prosecutors and defense attorneys, legal experts say.
Forkner, now a first officer for Southwest Airlines, referred questions to his attorney when reached by phone. His attorney, David Gerger, of Houston, did not respond to inquiries.
Mark Forkner, Boeing’s chief technical pilot on the MAX project, invoked the privilege in response to a grand jury subpoena issued by U.S. Justice Department prosecutors looking into the design and certification of the plane, the person said.
Invoking the Fifth to avoid testifying, while a legal right, is sometimes interpreted as an admission of guilt. Its use to resist a subpoena for documents is less common and may only imply a dance between prosecutors and defense attorneys, legal experts say.
Forkner, now a first officer for Southwest Airlines, referred questions to his attorney when reached by phone. His attorney, David Gerger, of Houston, did not respond to inquiries.
Forkner, who worked at Boeing from 2011 to 2018, according to his LinkedIn profile, was frequently anxious about the deadlines and pressures faced in the MAX program, going to some of his peers in the piloting world for help, a person who worked on the project previously told The Seattle Times, speaking on condition of anonymity.
The MCAS system, designed to move a powerful control surface at the tail to push the airplane’s nose down in certain rare situations, played a critical role in the crashes when the planes nose-dived out of the sky.
During the certification process, Forkner suggested to the Federal Aviation Administration (FAA) that MCAS not be included in the pilot manual, according to previous Seattle Times reporting.
The FAA, after internal deliberations, agreed to keep MCAS out of the manual, reasoning that MCAS was software that operates in the background as part of the flight-control system, according to an official familiar with the discussions.
The MCAS system, designed to move a powerful control surface at the tail to push the airplane’s nose down in certain rare situations, played a critical role in the crashes when the planes nose-dived out of the sky.
During the certification process, Forkner suggested to the Federal Aviation Administration (FAA) that MCAS not be included in the pilot manual, according to previous Seattle Times reporting.
The FAA, after internal deliberations, agreed to keep MCAS out of the manual, reasoning that MCAS was software that operates in the background as part of the flight-control system, according to an official familiar with the discussions.
While the Fifth Amendment protects people from testifying against themselves, it “usually does not apply to being required to produce documents because producing a document is not the same as being required to testify,” said University of Washington law professor Jeffrey Feldman.
But there are exceptions that allow the privilege to be asserted where “the mere act of producing the document” may be seen as an incriminating act, Feldman said.
Paul Rothstein, a Georgetown University law professor, said documents may show a person “has them, knows about them or admits they exist.”
“This information can often be somewhat incriminating of that person and thus covered by his Fifth Amendment privilege against self-incrimination,” Rothstein said.
Some courts have held that broad document requests require the person to “use his or her mental processes to interpret and respond to the subpoena, and the production itself could be viewed as testimonial,” said Peter Joy, a Washington University law professor.
In Forkman’s case, Feldman said, it could turn on the type of documents. “Are these the employee’s personal documents? His diary or personal emails? Or are they Boeing’s documents?”
Forkner could ask for immunity from use of the information in the documents, or prosecutors could offer it, the experts said.
But there are exceptions that allow the privilege to be asserted where “the mere act of producing the document” may be seen as an incriminating act, Feldman said.
Paul Rothstein, a Georgetown University law professor, said documents may show a person “has them, knows about them or admits they exist.”
“This information can often be somewhat incriminating of that person and thus covered by his Fifth Amendment privilege against self-incrimination,” Rothstein said.
Some courts have held that broad document requests require the person to “use his or her mental processes to interpret and respond to the subpoena, and the production itself could be viewed as testimonial,” said Peter Joy, a Washington University law professor.
In Forkman’s case, Feldman said, it could turn on the type of documents. “Are these the employee’s personal documents? His diary or personal emails? Or are they Boeing’s documents?”
Forkner could ask for immunity from use of the information in the documents, or prosecutors could offer it, the experts said.
On March 30, 2016, Mark Forkner, the Max’s chief technical pilot, sent an email to senior F.A.A. officials with a seemingly innocuous request: Would it be O.K. to remove MCAS from the pilot’s manual?
The officials, who helped determine pilot training needs, had been briefed on the original version of MCAS months earlier. Mr. Forkner and Boeing never mentioned to them that MCAS was in the midst of an overhaul, according to the three F.A.A. officials.
Under the impression that the system was relatively benign and rarely used, the F.A.A. eventually approved Mr. Forkner’s request, the three officials said.
The officials, who helped determine pilot training needs, had been briefed on the original version of MCAS months earlier. Mr. Forkner and Boeing never mentioned to them that MCAS was in the midst of an overhaul, according to the three F.A.A. officials.
Under the impression that the system was relatively benign and rarely used, the F.A.A. eventually approved Mr. Forkner’s request, the three officials said.