Environmental News

Discussion in 'Environmental Discussion' started by tochatihu, Oct 22, 2015.

  1. tochatihu

    tochatihu Senior Member

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  2. bisco

    bisco cookie crumbler

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    we get it, we get it :p

    good thing they're going all electric over there
     
    #622 bisco, Mar 13, 2019
    Last edited by a moderator: Mar 15, 2019
  3. tochatihu

    tochatihu Senior Member

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    Urban particulate pollution has stationary as well as fixed sources.

    ==
    Now to editorialize. Medicine including against cancer has made great advances. Public health (clean water in, pee pee and poo poo far away) and food sufficiency have reached down to almost the 'bottom' billion. Vehicular transport safety is improving, even with two of 'the same' making tragically poor landings.

    Point is that we are getting so good at maintaining and extending lives that subtle health risks are getting unmasked.

    Decades of breathing 100 micrograms per cubic meter of 2-micron particles mattered not at all in old times because something else got you first.

    If life expectancy is sort of plateauing (and I think it is), it points towards unmasking things like this. That is, if people want realistic shots at aging to 100.

    ==
    OK, a really poor car metaphor. Engine air filter needs changing? Autozone (TM). Human lung air filtration is a wonderful self-renovating system, but lacked evolutionary pressure towards so many decades of functionality.

    Many of us are past warranty at this point.
     
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  4. bwilson4web

    bwilson4web i3 and Prime

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    Source: Southwest is adding new angle of attack indicators to its 737 Max fleet - The Air Current

    "Currently, the MAX and NG have an AOA disagree light that provides an alert of erroneous AOA data" ...​

    Published in Nov 29, 2018.

    Source_2: https://www.bizjournals.com/dallas/news/2018/11/08/southwest-american-airlines-warning-boeing-737-max.html

    By Staff report
    Nov 8, 2018, 10:51am EST
    Southwest and American Airlines are making sure their pilots know how to respond to a potential sensor failure that’s at the center of an investigation into the crash of a Boeing 737 Max aircraft in Indonesia last week.

    Boeing (NYSE: BA) issued a service bulletin on Tuesday that instructs pilots how to work through sensor problems that could cause dangerous dives when aircraft are being piloted manually, as reported by the Dallas Morning News.

    The Federal Aviation Administration followed up Wednesday with an emergency airworthiness directive.

    Bob Wilson
     
    #624 bwilson4web, Mar 14, 2019
    Last edited: Mar 14, 2019
  5. bisco

    bisco cookie crumbler

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    USA Today reports there have been eleven u.s. pilot complaints about the planes behavior and training manual since the first crash
     
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    From what I've read, the whole problem comes from trying to put a 69" (175cm) fan in an application for a 40" (101cm) fan. 10lbs of sugar? Meet the 5lb sack.

    So now they dangle the engines way out front, jack up the front wheel to keep them out of the mud, and they don't tell the pilots about the new center of thrust vs mass relationship? And add software that could potentially emulate a slow runaway trim?

    They had already engineered a better way- telescopic landing gear to allow clearance for the big breathers. They could have kept their old thrust geometry, pod clearance, even the fuselage & gear bays stay the same. Some ground gear might have to change for the new cabin height. But stilts-on-demand isn't cheap, so they backed down.

    I realize that Boeing is trying very hard to not actually make airplanes given how deeply subcontracted these are but that seems like entirely too much "not-making". They need to clean up their act.

    I understand that a lab in France (Toulouse?) has the recorders from the Ethiopian Air wreck and that they are proceeding with data recovery. I'm hopeful for a clear reading such that everyone can learn and proceed.
     
  7. bisco

    bisco cookie crumbler

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    aren't we all
     
  8. tochatihu

    tochatihu Senior Member

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    u.s. pilot [email protected]

    Refers to NASA Aviation Safety Reporting System (ASRS). By my reading, two or 3 of the 11 seemed very similar with conflicts against automatic trim (attitude).

    Not all places have programs similar to ASRS. There may have been other trim battles with good outcomes, but an accurate count may not be possible.
     
  9. fuzzy1

    fuzzy1 Senior Member

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    Probably also to Boeing Field / King County Airport, which has more parking.

    A bit over an hour's walk.
     
  10. tochatihu

    tochatihu Senior Member

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    According to flightaware currently there are ~30 B38M and 4 B39M airborne. These have listed flight numbers and thus would not appear to be repositioning flights. As earlier I find this mysterious. Simplest guess (guess!) is that some other equipment is being flown but airlines have not provided that information.

    ==
    Boeing probably wants grounded planes to be where they can perform whatever modifications are finally settled on. Also where ramp space rental costs are low.

    ==
    At the time of Boeing 787 grounding there were 50 in service. Max 8 and 9 fleets together are ~370, so this is a bigger deal.
     
  11. bisco

    bisco cookie crumbler

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    not all pilots are created equal. weather conditions vary as well. it sounds like this plane has some poor characteristics that can be overcome with skill in most situations, but that does not seem to be the best way to design a new airplane.
     
  12. tochatihu

    tochatihu Senior Member

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    There has never been another airplane, so long re certified (grandfathered) with so many fundamental changes. Boeing's MCAS seems to be unique in this industry, and their pilot training about it may be as well. Not in a good way.

    All (?) prior aviation crash spikes improved the industry and I expect same this time. Families of squishees won't appreciate their roles there, or appreciate how legal reimbursement goes.
     
  13. fuzzy1

    fuzzy1 Senior Member

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    Not all airline training programs, maintenance programs, and adherence to safety protocols, are created equal. Lion Air was one of many airlines whose poor histories and practices got it banned from most First World operations for a while. Though they clawed their way back on to the approval lists not long ago. But even before their 737M8 crash, I would have been reluctant to fly on any of their aircraft, regardless of model.

    That said, 3 consecutive Lion Air crews apparently did respond correctly (though not necessarily immediately) to the ongoing situation that the ground crews were unable to diagnose and repair. (Maybe the model's troubleshooting documentation and procedures were also inadequate?)

    But the 4th crew ...

    That skill is supposed to be trained in to them, to follow the aircraft's flight manual and flip that automatic system to 'Off' if/when it misbehaves. Then fly the plane the old fashioned way, manually. Crew #4 failed to switch it off.

    Earlier local news reports indicated that this sort of behind-the-scenes, hidden-from-pilots automatic flight control system is relatively unusual for Boeing, but normal for Airbus which has many more similar automatic systems. (Maybe the former is not yet proficient at designing and wringing out such systems? ) But Boeing's change from its traditional design philosophy certainly wasn't adequately called out to the regular pilots.

    The Lion Air flight data, clearly showing conflicting reading from the two AOA sensors, practically screams out a clue before the plane ever left the ground. Software could easily be programmed to detect this clue and respond to it somehow, but Boeing's MCAS system does not currently do so. Southwest Airlines opted for the feature to light up a warning indicator in front of the pilots to alert them to this sensor conflict, Lion did not.

    I haven't yet had time to read about EA's history and reputations on these sorts of things. The EA flight data recorder is now in French hands, where it appears that the investigators went home for the night. Apparently not urgent enough to get to work on it immediately.
     
  14. fuzzy1

    fuzzy1 Senior Member

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  15. fuzzy1

    fuzzy1 Senior Member

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    It seems that a response to the disappearance of Malaysian Flight 370 -- commercial aircraft are now required to continuously report their positions by satellite -- quickly provided critical details about this EA flight's path, before the flight data recorders have been read. Such service was available at the time of the MH370 incident, but the carrier saved money by not subscribing. That choice is no longer allowed.
     
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  16. bwilson4web

    bwilson4web i3 and Prime

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    The planes are parked and they don't work for or own Boeing stock.

    Bob Wilson
     
  17. bisco

    bisco cookie crumbler

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    This is bringing to light some issues that Boeing and the industry in general would obviously have preferred to remain hidden.

    It always takes a tradgedy for humans to do the right thing
     
  18. tochatihu

    tochatihu Senior Member

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    When flight data recorder is ‘read’ in Paris, it will become clear whether these two accidents are strongly similar. Immediate prior replacement of one angle of attack (AoA) sensor in Lion Air means (at least) they are not completely identical.

    Now I have more information about AoA sensors which may be entirely accurate. All Boeings have two, left and right, near nose of plane. Airbuses have a different fundamental design philosophy, with more automation, using AoA information to control ‘normal’ flight. Two sensors are not enough for that role, as signals may disagree. Airbus thus adds a third one near the tail, and does majority rule.

    Back to Boeing and in particular 738 and 739 Maxes. Two AoA sensors that only come into direct action when they (or one of them) shows a too-steep climb. Then MCAS automatically applies nose-down trim. There is no display indication to pilots that MCAS is doing so, but it seems pilots would notice (unless it is very subtle?). With 2 sensors, voting one out is not an option. One operator (Southwest Airlines) adds a Boeing-optional AoA display on the main screen, with another indication if they disagree. This would likely help pilots to recognize problem (and solution) if AoA + MCAS points nose way down.

    Many sources agree that MCAS cutout is trivially done with one or two switches. 2018 November FAA emergency airworthiness directive (AD) told pilots (perhaps for the first time!) when and how to do this. Whether Ethiopian airline trained their pilots on this AD seems not to have been disclosed. I think it’s a very important question.

    Perhaps MCA software revision, and fitting all planes with AoA display information (also could be done in software), and training pilots for this fault in a simulator, would satisfy all parties. Time required would be whatever.

    However, recognize that basing a flight-control software function on 2 sensors seems not to be ‘industry practice’. Boeing might be obliged to add a third AoA sensor, in the style of Airbus. Physically modifying ~370 airplanes in service, and confirming that each one works in new implementation would take longer.

    All this is getting out in front of current crash investigation. There also has been recovered physical evidence (trim jackscrew) and its condition is consistent with uncorrected MCAS failure, as in previous crash. So I suggest it is not too soon to consider these possible responses.

    ==
    AoA sensors can fail for electrical reasons. They can get ‘iced up’. Even though very small targets, they could suffer bird or other object strikes. In Airbus world they are part of routine flight management and so are triplicated. In all other parts of Boeing world, they are just ‘nice to have’ sensors linked to conventional stall warnings like horns and stick shakers. In only these Boeing Maxes are they allowed to drive. Sometimes they don’t drive well at all.
     
  19. bwilson4web

    bwilson4web i3 and Prime

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    So you have two, AoA sensors and they disagree:
    • average the two - at least the plane will continue to fly without sudden changes in attitudes
    • switch between - the good one tries to maintain flight, the bad one wants to do 'something bad'
    Just speculation.

    Bob Wilson
     
  20. fuzzy1

    fuzzy1 Senior Member

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    * Watch them both during the takeoff roll, before the nose wheel leaves the ground, when there is a 'ground reference' for AOA. In the Lion Air incident, one of them was already very obviously whacked during this phase of the journey. Unfortunately, that was also the one driving MCAS. Software could / should have set it aside as known-bad.
     
    #640 fuzzy1, Mar 16, 2019
    Last edited: Mar 16, 2019
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