Ethiopian 737-8 MAX down. No survivors. | Page 20 | FerrariChat

Ethiopian 737-8 MAX down. No survivors.

Discussion in 'Aviation Chat' started by RWatters, Mar 10, 2019.

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  1. tazandjan

    tazandjan Three Time F1 World Champ
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    There have already been several articles in Aviation Week.
     
  2. Bob Parks

    Bob Parks F1 Veteran
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    Okay. You must be peeking ( as the Imogee indicates) or I'm not using all three of these wind angle sensors. They change when the number of scotches increase and sometimes only one of them works when in a spin.
     
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  3. Nurburgringer

    Nurburgringer F1 World Champ

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  4. TheMayor

    TheMayor Nine Time F1 World Champ
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  5. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    Be aware in the comments section that there are some very vocal people that have absolute blinders on as "pro-Airbus" fanboys. They take every opportunity to bash Boeing whether valid or not. After a while you should start to notice some tendencies by many of these commenters and get a feel for which are worth listening to.

    Article within the last couple of days where two different industry experts were predicting the replacement 737 - necessity to get it seriously underway, timeline, if it changed the priority from the Middle of Market aircraft, does the new aircraft increase the minimum passenger capacity, and more. Minimal agreement between these two on even the need to get underway on the all new design.
     
  6. TheMayor

    TheMayor Nine Time F1 World Champ
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  7. jcurry

    jcurry Two Time F1 World Champ
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  8. TheMayor

    TheMayor Nine Time F1 World Champ
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    Sorry I meant 737 Max's. Mistyped!

    So its a positive sign for the Max.
     
  9. Argosy

    Argosy Formula Junior

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    It's not a firm order yet. I'm guessing Boeing had to offer some heavy discounts and there are probably conditions that need to be met.
     
  10. TheMayor

    TheMayor Nine Time F1 World Champ
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    I bet you are CORRECT!
     
  11. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    But it is a positive sign from IAG which is an Airbus 320 operator across its brands that include British Airways and Iberia.
     
  12. jcurry

    jcurry Two Time F1 World Champ
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    Pilots better start working out.
    https://www.wsj.com/articles/physical-strength-of-pilots-emerges-as-issue-in-returning-737-max-to-flight-11560937879
     
  13. nerofer

    nerofer F1 World Champ

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  14. ChipG

    ChipG Formula 3

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    It should never fly again.
     
  15. INRange

    INRange F1 Veteran
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    I just don't understand why they don't disable MCAS completely and let the pilots fly the plane.
     
  16. BubblesQuah

    BubblesQuah F1 World Champ
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    I don't understand why "someone", other than Boeing itself, continues to find problems.

    Seems to me there are only 2 options - Boeing doesn't understand everything about its product or Boeing does understand everything about its product and doesn't consider these things problems.
     
  17. Fave

    Fave F1 Rookie

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  18. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    From a reliable source, Aviation Week.

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    Collins Aerospace

    WASHINGTON—FAA test pilots have flagged a new issue in the Boeing 737 MAX flight control system that must be addressed as part of changes being made to get the aircraft back into service, Aviation Week has learned.

    The issue came to light within the last week during tests in Boeing’s MAX engineering flight simulator, or e-cab, a source with knowledge of the situation confirmed. The pilots were simulating a runaway stabilizer scenario and running through the requisite emergency-response checklist. A key early step is to use control column-mounted electric-trim switches to command horizontal stabilizer movement to counter the runaway. A subsequent step, if needed, is to toggle cutout switches that disable the trim motors.

    According to the source, the FAA pilots found response to the electric-trim inputs took too long. “They had a difficult time quickly resolving the situation,” the source explained.

    The issue has been traced to how quickly a specific flight control computer chip is processing data, the source said. What is not clear: whether the chip itself needs to be changed, or if a software update will address the issue. A second industry source said that a software fix is possible—and certainly would be preferable for Boeing, which suggested in a statement that a software modification will be sufficient. Changing chips could further delay the MAX’s return to service, as it would likely require new chip architecture as well as changing chips on nearly more than 500 MAXs in airline fleets or ready to be delivered.

    “The FAA is following a thorough process, not a prescribed timeline, for returning the Boeing 737 MAX to passenger service,” the agency said in a statement. “The FAA recently found a potential risk that Boeing must mitigate.”

    Boeing said the issue is “an additional requirement” that the FAA “has asked the company to address through the software changes that the company has been developing” for the MAX. “Boeing agrees with the FAA’s decision and request and is working on the required software to address the FAA’s request. Addressing this condition will reduce pilot workload by accounting for a potential source of uncommanded stabilizer motion,” it added.

    The MAX has been grounded since mid-March following two fatal accidents in five months. Boeing has been working on changes to the MAX’s flight control system, specifically the maneuvering characteristics augmentation system (MCAS) flight control law. MCAS commands automatic horizontal stabilizer inputs in certain flight scenarios, and it activated erroneously in both accident sequences. Its failure can result in a runaway stabilizer scenario, which pilots are supposed to mitigate by following the “stabilizer runaway” checklist. Trimming the aircraft using the control-column switches is a key first step meant to stabilize the aircraft and enable the pilots to safely de-power horizontal stabilizer trim motors using cutout switches mounted on the aircraft’s center console.

    In both accident sequences—the October 2018 crash of Lion Air Flight 610 and Mar. 10 crash of Ethiopian Airlines Flight 302—the crews used the column-mounted switches to counter MCAS. Neither followed the runaway stabilizer checklist step-by-step, and were overcome by MCAS’s repeated inputs that forced the aircraft’s nose down due to erroneous angle-of-attack data being fed to the flight control computer. Both accident sequences ended with uncontrollable dives.

    The newly discovered issue came up during a very specific failure scenario, and it is not clear whether it has any link to either MAX accident sequence, the first source emphasized.
     
  19. boxerman

    boxerman F1 World Champ
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    Boenig needs to rename the max, which sonds like a tampon anyway, a minor example of how pr clueless boenig is.

    Fundementaly theyre patching over patches, making a 60s streteched and stretched again and streched again design work, essentialy a past its sell by date aircraft work. This was the rush to market option rather than developing anew aircraft, which would have been more expensive and taken longer.

    In the end MCAS was poor practice, and I highly doubt that the people who developed the 777 would have done this. Its what happens when you move your headquatrers and decsionmaking from the shop floor to Chicago.

    In the short term Boeing can get away with it, simply because airlines have no other options, airbus is way sold out. in the longer term an articulated landing gear to make the 737 sit higher so bigger engines again can be fitted is yet another patch and not good practice. Boeing needs to bite the bullet and develop a new aircraft for this category.

    It takes no genius to realize that if there were other deliverable options no one would be another a max, and thats not a good.

    Addtionaly Boeing needs to redevelop its product development process, less MBA more solid enginering.

    the A320 was at a disadvantge when it came out because it was heavier and less efficient, plus more expensive to porduce being a new design not amortised. But the A 320 had development potential the 737 is struggling to match now and the A320 has a ways to keep going.

    Frankly what happened with the 737 max should not happen in the 21st century, after all these years of aviation experience and good practice.

    How MCAS made it as it was into a prductio aircraft, past however many comitees and reviews is the real scandal, and we read nothing about that, which implies Boeings internal processes are really flawed.
     
  20. F1tommy

    F1tommy F1 World Champ
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    This whole issue has more to do with Boeing arrogance in both management and engineering more than anything else. A fully competent and trained crew that made no mistakes should have been able to save both the 737's that crashed. The problem is Boeing should have made it less difficult to correct the bad situation. Their initial reaction to the first Lion Air crash says it all. But the airplanes in my opinion should not have crashed if the pilots had followed procedures correctly, so some arrogance on the 737 crews also for not checking into the issues after hearing of problems especially the second crash flight crew.
     
  21. jcurry

    jcurry Two Time F1 World Champ
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    It already is. There is a trim switch on the control yokes. The issue is that part of the emergency actions when there is a runaway trim is to turn off the powered system.
     
  22. Fave

    Fave F1 Rookie

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    So the power that they are cutting off is a motor that turns the wheel it's self in-turn pulling the cables to the trim?

    I thought turning off the power was for hydraulic motors which move the trim. That's why I was asking if the manual wheel could be power assisted, like a car's steering wheel, to help with move the cables to the trim.
     
  23. jcurry

    jcurry Two Time F1 World Champ
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    I believe that when a pilot uses the trim switch the trim wheel does move. I would have to research where the motor is in the system, but it is connected to the cables or directly to the jackscrew, but is not independent of the cable system and wheel.

    Yes they could add another motor that is independent of the autopilot and other flight control system functions (MCAS), but that adds complexity and costs where none has been needed in the past.
     
  24. jcurry

    jcurry Two Time F1 World Champ
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  25. Tcar

    Tcar F1 Rookie

    Thought I read that engaging the autopilot shuts off the MCAS system totally.
    And lowering the flaps, even minimum, does the same...
     
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