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    Might the aeroplane have been travelling 50 knots too fast because the MCAS had forced it into a dive?

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    Quote Originally Posted by Mark Rand View Post
    Might the aeroplane have been travelling 50 knots too fast because the MCAS had forced it into a dive?
    See also "coffin corner" above. Most likely caused by magic. NOT repeat NOT anything that sounds remotely like

    MCAS.

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    Quote Originally Posted by jim rozen View Post
    See also "coffin corner" above. Most likely caused by magic. NOT repeat NOT anything that sounds remotely like

    MCAS.
    See also post 971 above. Most likely caused by untrained, inexperienced and unskilled drivers. NOT repeat NOT anything that sounds remotely like

    PILOTS.

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    I think that one of the takeaways from these crashes will be better training for crews to recognize the symptoms of bad air data, and better cockpit warnings. It's a recurring theme, the number of crashes involving failed AOA vanes and/or pitot icing is a pretty long list.

    We've talked about it before- we want crews to follow the procedures precisely- any deviation turns them into test pilots with a plane full of passengers.

    The first crash (JT610), they were flying a plane that was not airworthy because one stick shaker was active continuously. The second crash (ET302), they rotated into the stick shaker.

    Both flights has the IAS DISAGREE warning, which should have triggered the checklist. Set pitch to 10 degrees and power to 80%. Both flights would have been stable at those settings. ET302 would have still been at takeoff flaps, and MCAS would never have activated. They could have just turned around and landed the plane without incident.

    JT610 should have never taken off, but the same situation was presented to the crews. IAS DISAGREE. Set pitch to 10 degrees, power to 80%, they would have been at F5 so no MCAS. Turn it around and live to fly another day.

    Both crews failed to follow the procedure, both crews tried to continue the flight when they should have aborted and sorted out the problems on the ground. In each case, the plane was telling them they had bad air data, but they failed to recognize the problem.

    I'm not exonerating Boeing for the faults in the MCAS design- those are real. But airline crashes are never single-factor causes. It's always a combination of factors- often any one of which if you changed, the crash would have been averted.

    Here's an example of the crew getting it right in a similar situation:

    http://www.bst-tsb.gc.ca/eng/rapport...1/a11o0031.pdf

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    Quote Originally Posted by jancollc View Post
    I think that one of the takeaways from these crashes will be better training for crews to recognize the symptoms of bad air data, and better cockpit warnings. It's a recurring theme, the number of crashes involving failed AOA vanes and/or pitot icing is a pretty long list.

    We've talked about it before- we want crews to follow the procedures precisely- any deviation turns them into test pilots with a plane full of passengers.

    The first crash (JT610), they were flying a plane that was not airworthy because one stick shaker was active continuously. The second crash (ET302), they rotated into the stick shaker.

    Both flights has the IAS DISAGREE warning, which should have triggered the checklist. Set pitch to 10 degrees and power to 80%. Both flights would have been stable at those settings. ET302 would have still been at takeoff flaps, and MCAS would never have activated. They could have just turned around and landed the plane without incident.

    JT610 should have never taken off, but the same situation was presented to the crews. IAS DISAGREE. Set pitch to 10 degrees, power to 80%, they would have been at F5 so no MCAS. Turn it around and live to fly another day.

    Both crews failed to follow the procedure, both crews tried to continue the flight when they should have aborted and sorted out the problems on the ground. In each case, the plane was telling them they had bad air data, but they failed to recognize the problem.

    I'm not exonerating Boeing for the faults in the MCAS design- those are real. But airline crashes are never single-factor causes. It's always a combination of factors- often any one of which if you changed, the crash would have been averted.

    Exactly!

    We had an "unrealiable airspeed" drill on the bus:

    0-1500' *** Pitch 15*/TOGA (full) thrust

    1500'-10,000' *** Pitch 10*/climb thrust

    10,000' - above *** Pitch 5*/cruise thrust

    Flaps *** Leave at current position

    Speedbrakes *** Retract

    Landing Gear *** Retract


    Following this would have probably saved AF447 as well.

    I remember the old timers I worked with on the 767 pointing to the computer generated flight instruments and nav displays (these were all new at the time) saying "These things will kill you! These things (raw data) won't".

    How right they were...
    Last edited by Terry Keeley; 10-22-2019 at 10:35 PM.

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    I just caught something on the radio over here. Apparently the families of the victims of the first crash have been briefed on the contents of the official report. Boeing gets some blame, as do the pilots, how the blame is divided up they didn't say.

    The report is due to be published on Friday.

    Edit - reading the " New York Times " report today the blame seems to be apportioned fairly.

    Regards Tyrone.
    Last edited by Tyrone Shoelaces; 10-23-2019 at 12:12 PM.

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    That didn't go so well for Boink.....

    'Flying coffins': senators rip Boeing chief over Max jet crashes that killed 346 | Business | The Guardian

    the headline

    'Flying coffins': senators rip Boeing chief over Max jet crashes that killed 346


    From the article

    Asked if Boeing could have done more after the first 737 Max crash, Muilenburg said: “I think about that decision over and over again. If we knew then what we know now we would have made a different decision.”

    The Democratic Illinois senator Tammy Duckworth, a former military pilot, questioned why Boeing did not disclose more details about anti-stall system’s lack of safeguards.

    “You have told me half-truths over and over again,” Duckworth said. “You have not told us the whole truth and these families are suffering because of it.”

    Duckworth said the pilots did not know enough about the anti-stall system. “You set those pilots up for failure,” she said.


    Ted Cruz has his say

    At issue are recently disclosed internal instant messages that Boeing had not previously handed to committee investigators. The messages, sent by Boeing’s chief test pilot Mark Forkner in 2016, complained of “egregious” erratic behavior in flight simulator tests of the MCAS system, and referred to “Jedi mind tricks” to persuade regulators to approve the plane.

    Muilenburg claimed he was not fully briefed on the details of the messages until a “couple of weeks ago” despite the company knowing of the exchange before the Ethiopian airlines crash.

    The Texas Republican senator Ted Cruz called the test pilot’s exchange “shocking” and accused Boeing of withholding knowledge of the systems faults from regulators.

    Cruz said: “How come your team didn’t come to you with their hair on fire, saying, ‘We’ve got a real problem here’? What does that say about Boeing? Why did you not act before 346 people died?”

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    You *know* you have a problem when ted cruz is all over you.

    Somebody here better pass the hat for that corporation here, SOON. Maybe the
    apologists here could pony up what, maybe 150 bucks?

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    Quote Originally Posted by jim rozen View Post
    You *know* you have a problem when ted cruz is all over you.

    Somebody here better pass the hat for that corporation here, SOON. Maybe the
    apologists here could pony up what, maybe 150 bucks?
    You didn’t hear? The US Taxpayers are bailing them out of this mess with a Cost+ contract for 10 more over priced, over budget, delayed SLS rocket cores.

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    Boeing has had systemic problems for quite a while. From tools and debris left in fuel tanks of military jets that were delivered as "good" to the Air Force (Boeing tanker jets grounded due to tools and debris left during manufacturing | The Seattle Times), to trying to push 787 production beyond "proper" capacity (Claims of Shoddy Production Draw Scrutiny to a Second Boeing Jet - The New York Times), to multiple wing design flaws on the 737 (Boeing 737: wing problems possible in over 100 aircraft , Operators Ground 38 Boeing 737NGs for Pickle Fork Cracks | Air Transport News: Aviation International News).

    All follow decades of Boeing carving up its inhouse engineering and manufacturing capability and leadership. Beancounters have ruled, and as they have they've destroyed the engineering heart of a once-great company. How often have we seen this before, and how many more times will it happen again?

    [Trick question - it'll forever happen again, as long as rewards for the "C" suite rule over good business processes]

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    Here's some more info on the wing attachment problems of some 737NG (No Good?) aircraft: Boeing’s 737 in another pickle, Part 2 - Leeham News and Analysis

    On topic: I take it these "pickle forks", of which there's four per aircraft, are monolithic machined parts. I haven't found a really detailed picture of them yet, so that guess may not be correct. But if it is some shop's just got a windfall rush project.

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    Quote Originally Posted by Milland View Post
    Here's some more info on the wing attachment problems of some 737NG (No Good?) aircraft: Boeing’s 737 in another pickle, Part 2 - Leeham News and Analysis

    On topic: I take it these "pickle forks", of which there's four per aircraft, are monolithic machined parts. I haven't found a really detailed picture of them yet, so that guess may not be correct. But if it is some shop's just got a windfall rush project.
    The comment attached caught my eye...
    I do wonder if there's processes that Boeing have forgotten throughout the years?
    Design which has been apparently simplified, or cost down, without the design team actually realising the ramifications.

    I put an example back along regarding the 787 when they had a huge fire which nearly downed one of the first three test planes, because they changed manufacturers and went with FR4 board material rather than Norplex (non fire resistant against fire resistant) to save money.
    The original 757 airframes had tried FR4, had fires, changed to Norplex and all was okay, then continued to use it for the 767 and 777.
    But come 787, new supplier and *cost down*...

    I also say this because my old main customer (where I did my apprenticeship) went through a couple of projects costing huge pain - one where they've spent 4.5mill to date and the new generation instrument isn't half as good as the original - and I remember speaking with the (contract) design engineer when I first met him on the project.
    I asked "did you read the design files for the old instrument as they're very interesting" - his reply, "nah mate, clean sheet of paper".
    The other project (next generation instrument) had 4x complete re-designs to meet vibration and the latest is that it still costs 20% more than the original instrument with still less functionality...
    But as the design engineer said to me (contractor) "I don't worry about cost - I just worry about function"...

    What I have read on a press release from Boeing, is that my understanding is they're going back to an overall chief engineer type set-up.
    This is such a good thing.

    Independent project teams have been my personal pet hate since they were vogue to introduce them back in the '90's - you cannot beat a drawing office/Chief Draughtsman type arrangement, where you have overall company ownership of technology.
    Project teams tend to be ran by accounts, so are ran by contractors with contractors hired as and when needed - and no disrespect to them, Ford wouldn't throw someone into designing a cylinder head who'se never worked in that industry before would they?.
    Well, perhaps...
    Attached Thumbnails Attached Thumbnails capture.jpg  

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    Boeing needs to find a lock of hair from Clarence Johnson (yes, I know he was Lockheed) and clone a few dozen Kelley's to get back into the blue.

    On that note, it sounds like they're saying the crack initiates at the bolt hole and works its way out. If there's too much movement of the bolt within the hole leading to contact stresses perhaps a very close (or mild interference) will prevent initiation.

    On the cold working: cracks tend to not start within compressively loaded surfaces, so maybe they're trying to burnish the bore before fastener fitting?

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    Quote Originally Posted by Milland View Post

    On the cold working: cracks tend to not start within compressively loaded surfaces, so maybe they're trying to burnish the bore before fastener fitting?
    So you ream a hole to good size by hand (wobbly?) For a good size bolt?
    But reamer has tolerance and so does bolt shank?
    So there's still clearance which allows for *some* movement?
    Where a rivet would compress and fill the gap?

    It does seem that if you have to rely on a lesser and therefore tighter clearance for something that either works or doesn't, then the concept is very close to the edge...

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    Quote Originally Posted by barbter View Post
    So you ream a hole to good size by hand (wobbly?) For a good size bolt?
    But reamer has tolerance and so does bolt shank?
    So there's still clearance which allows for *some* movement?
    Where a rivet would compress and fill the gap?

    It does seem that if you have to rely on a lesser and therefore tighter clearance for something that either works or doesn't, then the concept is very close to the edge...
    Too much Spanish wine if you're wobbling while reaming...

    Reading the attachment you posted again, they are reaming for a *interference* fit for an oversize threaded fastener, so there you go - not just for rivets anymore. And bolts are a heck of a lot easier to remove for inspection of the mate, unlike a bucked rivet. Granted, they take more space and weight than a properly installed rivet, but for such a critical part I can see why the choice for bolts was made.

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    Quote Originally Posted by Milland View Post
    Too much Spanish wine if you're wobbling while reaming...
    Dehaviland (Airspeed) Factory was 2 miles up the road from me. Quality came from there...
    BAC Hurn was 6 miles in the other direction - and I had some mates who worked there and heard stories of how things were precision "windy" drilled with a wobbly hand and a bad eye...

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    The FAA investigator guy stopped in my shop again- in essence said the problem started with a airframe foible of the engine position (low slung engine) causing a pitch up nose at some flight speeds.

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    Quote Originally Posted by triumph406 View Post
    the headline

    'Flying coffins': senators rip Boeing chief ...
    Oh yeah, like senators know doodly-squat about airplanes. They can't even pass a simple budget, but they feel competent to criticize aerospace engineers.

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    Quote Originally Posted by EmanuelGoldstein View Post
    Oh yeah, like senators know doodly-squat about airplanes. They can't even pass a simple budget, but they feel competent to criticize aerospace engineers.
    In the "modern" Boeing, even if you have an engineering background, by the time you reach the C-suites you've become an beancounter podling. If you make decisions to put a massive, fault-intolerant band-aid called MCAS in place because you wanted to sell planes rather than require proper training and certifications for pilots in what's essentially a new platform then you've set aside engineering for money.

    Federal or state budgets are subject to constraints and political maneuvering and frequently has poor efficiency/dollar results. Designing a plane that will fly safely (including correct training as needed for the pilots) is an engineer's job, not a MBA's, and cannot be constrained by decisions to squeeze the last dollar from the build. If you do that, you set the company up for massive failure and a loss of reputation.

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    Quote Originally Posted by Trboatworks View Post
    The FAA investigator guy stopped in my shop again- in essence said the problem started with a airframe foible of the engine position (low slung engine) causing a pitch up nose at some flight speeds.
    That sums up what appears to be the problem in a sentence. Fitting new, bigger, engines on an old air frame design.

    Regards Tyrone.


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