MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
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https://www.cnbc.com/amp/2019/09/18/...e-himself.html
Can he really fly the plane before certification?
Can he really fly the plane before certification?
... somebody is already doing so, by "utilizing the 737 Max during planned maintenance movements".
Not just sim sessions in Canada...
Globe & Mail: "Lone Boeing 737 Max flew in Canadian airspace for pilot checks during grounding"
https://www.theglobeandmail.com/busi...checks-during/
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https://newrepublic.com/article/1549...ial-revolution
That is a very comprehensive, long and ugly read.
That is a very comprehensive, long and ugly read.
Psychophysiological entity
It was a long read only to find an increasing number of rather revealing statements make me question the accuracy of the whole.
This history was interesting but I felt an increase in the blurriness building up before the above statement.
The only way to retrim the airplane at these speeds would be to use the much more powerful electrohydraulic mechanism associated with the thumb switches,
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It's more then chilling - and this is what the USAF now faces with commodity driven seniors at the helm proclaiming software is just software as they come from a powerpoint business environment mission which has absolutely NO similarity to keeping an aircraft in the air.
You may not have meant to, but you implied that no trim functions would stop, as if the cutout was no longer there.
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RE the electro hydraulic -the classics dId have such a system ( two of them re stabilizer )- but somewhere in the transition thru to Current NG models, the two electro hydraulic units were replaced by ONE electric motor. No doubt as cost savings. And as I recall from reading more posts here and elsewhere, and knowing a few non told stories re the ' birth of the NG' and the mess caused by the related MDC " buyout"- (-IMHO as a SLF retired Boeing type) - The confusion re control systems is not a surprise. Suggest the trolls take the time to read other sites .... satellite guru and Bjorn and leeham and seattle times before blovisating. I did find in the TECH forum a sticky ? re earlier posts on the whole 737 mess. Worthwhile taking the time to read..
Last edited by Grebe; 19th Sep 2019 at 17:52. Reason: clarify wording re confusion re control systems-
Not sure if anyone has posted a link to the NY Times review mag this week. Interesting comments.
https://www.nytimes.com/2019/09/18/m...sultPosition=2
https://www.nytimes.com/2019/09/18/m...sultPosition=2
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Of course the narrative is, necessarily, compressed and not every event and development can be included. But I can't tell what the point of your observation is. Do you think the narrative in the New Republic piece is particularly flawed in some way, or that it paints an inaccurate picture?
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One human factor that escaped the MCAS designers is the cockpit confusion and startle factor when an apparent trim movement can't be stopped by the column cutout, behavior that was not documented
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That Langewiesche piece is weird. I met the author many years ago, and I'm familiar with his work since then - but this is unusually like polemic.
In its functioning, the electric trim is smooth, powerful and usually well behaved. On occasion, however, it may start running on its own volition and prompt the airplane to nose up or down. That’s a runaway trim. Such failures are easily countered by the pilot — first by using the control column to give opposing elevator, then by flipping a couple of switches to shut off the electrics before reverting to a perfectly capable parallel system of manual trim. But it seemed that for some reason, the Lion Air crew might not have resorted to the simple solution.
As has been discussed frequently in this thread, that "some reason" was that AoA-failure-induced MCAS action doesn't look like runaway trim, because it responds to cancellation with the yoke switches. Therefore the impression is that the trim is controllable, and that the "simple solution" - leaving the pilots coping with heavy hand-trim loads, because in that regard the system is not "perfectly capable" - doesn't have to be invoked. But pilots are trained to use trim sparingly, and are understandably reluctant to pile on ANU trim with the stall-warning going, and are not aware that MCAS is going to apply AND trim at a perilous rate. Which in turn tends to increase speed and push the nose down, even while the same root cause is blatting out stall warnings.
The writer manages to avoid the obvious points: that once an erroneous MCAS action kicked in, the crew had become test pilots; and there's no control case where a skilled Western crew safely dealt with the problem.
On the other hand, the TNR story isn't that good either, particularly in its attempt to depict GE-trained leaders as the villains of the piece. Boeing's "problem-solving" culture had brought it to the brink of catastrophe before the McDonnell Douglas people arrived, by failing to deal with a dysfunctional production system, and it was classic Boeing people - Mulally and Condit - who turned the new-product-development process into an alternating sequence of moonshots (777, 787) and derivatives. Muilenburg, another veteran engineer-manager, has enthusiastically pushed the gospel of shareholder value.
In its functioning, the electric trim is smooth, powerful and usually well behaved. On occasion, however, it may start running on its own volition and prompt the airplane to nose up or down. That’s a runaway trim. Such failures are easily countered by the pilot — first by using the control column to give opposing elevator, then by flipping a couple of switches to shut off the electrics before reverting to a perfectly capable parallel system of manual trim. But it seemed that for some reason, the Lion Air crew might not have resorted to the simple solution.
As has been discussed frequently in this thread, that "some reason" was that AoA-failure-induced MCAS action doesn't look like runaway trim, because it responds to cancellation with the yoke switches. Therefore the impression is that the trim is controllable, and that the "simple solution" - leaving the pilots coping with heavy hand-trim loads, because in that regard the system is not "perfectly capable" - doesn't have to be invoked. But pilots are trained to use trim sparingly, and are understandably reluctant to pile on ANU trim with the stall-warning going, and are not aware that MCAS is going to apply AND trim at a perilous rate. Which in turn tends to increase speed and push the nose down, even while the same root cause is blatting out stall warnings.
The writer manages to avoid the obvious points: that once an erroneous MCAS action kicked in, the crew had become test pilots; and there's no control case where a skilled Western crew safely dealt with the problem.
On the other hand, the TNR story isn't that good either, particularly in its attempt to depict GE-trained leaders as the villains of the piece. Boeing's "problem-solving" culture had brought it to the brink of catastrophe before the McDonnell Douglas people arrived, by failing to deal with a dysfunctional production system, and it was classic Boeing people - Mulally and Condit - who turned the new-product-development process into an alternating sequence of moonshots (777, 787) and derivatives. Muilenburg, another veteran engineer-manager, has enthusiastically pushed the gospel of shareholder value.
Of course the narrative is, necessarily, compressed and not every event and development can be included. But I can't tell what the point of your observation is. Do you think the narrative in the New Republic piece is particularly flawed in some way, or that it paints an inaccurate picture?
I don't know if it's flawed or inaccurate, just that it benefits from hindsight.
Don't take any of it to say Boeing was correct in not explaining the system and the changes better.
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Got it. Thanks.
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Boeing's "problem-solving" culture had brought it to the brink of catastrophe before the McDonnell Douglas people arrived, by failing to deal with a dysfunctional production system
Having worked in that area on 777, and on the mostly non public B2 manufacturing areas, i dont recall such an issue. But about a year after the MDC buyout in 1996, Boeing had to shut down its production line in everett in 1997 due to the fouled up incorporation of a new cure all computer system and the infusion of way too many MDC types.
From wiki
The BoeingCo. It has also divested 5 assets. The Boeing'slargest acquisition to date was in 1996, when it acquired McDonnell Douglas for $13.3B. It's largest disclosed sale occurred in 2005, when it sold Spirit AeroSystems to Onex Partners for $375M. The Boeinghas acquired in 10 different US states, and 4 countries.