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Thread: The lion air accident

  1. #11
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    Quote Originally Posted by Bill Greenwood View Post
    Ron , I receive a check from Exxon so when the media reported that Exxon had spilled a lot of oil in the water in Alaska, the explanation must be that he media is lying?
    Better re-check what I said. I never said the media is lying; they're expressing an opinion without understanding the facts involved. They're reporting what "sells papers," without the technical expertise to tell if it's correct. Being stupid is not the same as lying.

    About twenty years ago, a local company chartered an airliner for a flight around the world. No real reason for it, except for a unique experience.

    The local media covered it pretty well, especially one older couple. The man claimed he had been afraid to fly all his life, and had bought his ticket on the around-the-world flight to finally face his fear.

    The media ate it up. The story was too good to fact-check.

    Turns out the guy was a retired airline pilot. Yes, he lied, not the media. But no one bothered to make a cursory check of the man's background. The media didn't lie...but they sure were stupid.

    Ironically, this was in Seattle, where the media SHOULD be pretty good at aviation stories.

    Quote Originally Posted by Bill Greenwood View Post
    The weak spot in you analysis , is while Indonesia and their version of NTSB may be incompetent and even corrupt like lots of other 3rd world countries, their board did not cause the crash. If there was no defect in the airplane there would have not been an emergency, and he pilots would not have had to try to overcome the out of control pitching. How do we know about the pitch fluctuations? It is reported from the data from the black box recovered. but then again maybe the media, NBC news just made all this up and is lying.
    Oh, I don't doubt that there was a fault in the airplane...and have never claimed there wasn't. I merely question the ability of NBC/FOX/CNN to understand what potentially biased sources might be telling them. I'm confident in the NTSB's ability to assess the evidence without bias, but they're just an observer at this point. The Indonesian equivalent will make the final ruling. I don't know much about them, but know that some countries look at these sorts of things a bit different.

    Some good examples can be found in "Flying Upside Down," a book allegedly written by a Western pilot who flew for a Chinese airline. I have no idea if it's "for real" or not, but there's a huge amount of rather scary detail about a national aviation establishment supposedly being driven primarily by political, not technical, issues.

    https://www.scribd.com/doc/273231452...pside-Down-pdf

    A fundamental aspect of aircraft design is to minimize the potential for any failure to cause injury or death. That's why certified engines have dual ignition systems, why retractable-gear aircraft have emergency gear-extension systems, why the Space Shuttle has five parallel computer systems, with one using completely different hardware and software from the four primary computers. Redundancy. Fall-back modes. Good stuff.

    Allow me to speculate for a moment, based on what I've heard. I've heard the Lion Air aircraft had a failure in either the airspeed or angle of attack sensor. Surely the type of thing that can happen. From what I understand, the 737 has a fall-back mode in these cases, where the pilot switches to an alternate control mode and then must fly the aircraft without a lot of the software "helpers" these modern aircraft include.

    Now, again, I understand that this failure occurred on a previous flight. The previous crew switched to this alternate mode, and landed safely.

    And as I posted earlier, two questions arise: Was the previous failure fixed, and was the repair tested to published Boeing procedures?

    Then comes the second question: If the problem hadn't been fixed...or the same one cropped up again...what was different about the second crew that they were not able to successfully use the alternate mode? Was it a totally different type of failure?

    Boeing's culpability basically rests on the answers to these questions. Things break. The key point is whether the crew can still successfully land the airplane, and whether using Boeing's repair procedures will correct the issue. If the failure was not properly repaired, would the standard, published Boeing diagnostics have made the faulty repair clear to the maintainer? Was the aircraft returned to service because of a failure of a correctly-executed process, or because the managers of a bargain basement airline HAD to get the plane back into service? An airline with a trouble history along these lines?

    After all, they had justification for this: The previous crew was able to handle the anomaly and safely complete their flight. There are some managers who might take that as an indication that the "problem" isn't really a problem.

    But...then we get in the same situation: Why was one crew able to handle the anomaly, but not the other? If you read the "Flying Upside Down" book, one of the writer's complaints is that pilots were assigned to fly aircraft based on political "pull," not their technical expertise. I'm wondering if we're looking at the same sort of situation.

    Finally, Bill, you might be familiar with the name Wolfgang Langewiesche. He wrote one of the most famous books about how to fly.

    His son William is a crackerjack aviation writer, too. Vanity Fair magazine published an incredible article about the crash of Air France 447, the plane lost over the south Atlantic about ten years ago.

    https://www.vanityfair.com/news/busi...ight-447-crash

    It sounds like a very similar sort of accident: A failure of a sensor. Yet the crew couldn't handle it. It was an Airbus, not a Boeing, which might indicate an overall pilot issue rather than something specific to an aircraft type.

    So I'm waiting to see a technical assessment of the accident, and tend to discount any non-technical-media coverage.

    Ron Wanttaja

  2. #12
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    Quote Originally Posted by Kyle Boatright View Post
    What about turning off the automation if it isn't working right.? Alternately, report and fix the issues experienced by the crew on the previous flight before another passenger carrying flight. The man is in the loop because we know automation works extremely well *most* of the time, not all of the time.
    Let me tell a story that's closer to our own experience.

    About ten years ago, a good friend was taking off from Port Angeles airport in Washington state in the RV-7 he'd built. Not long after takeoff, the engine started running horribly rough. With nothing but Pacific Ocean in front of him, he tried to turn back to land. The aircraft stalled at low altitude and crashed on the beach.

    The NTSB found that the Lycoming had two ignition systems, but one was a more-modern electronic one. The other was a standard magneto. The electronic ignition had slipped timing, causing a loss of power due to misfiring.

    Now...what do we blame this accident on?

    The failed ignition? Well, certainly, its failure led to the loss of power and the accident. But the Lycoming in the RV-7 was designed for, and implemented, two completely-independent ignition systems. It's DESIGNED to keep running...and during pilot training, we're taught to switch the mag switch early in the engine-failure assessment process.

    Any mechanical device can fail. The point, in aviation, is to provide backup/fallbacks to minimize the chance of a single mechanical failure causing an accident.

    So was the accident due to the failure of the ignition...or due to the pilot not executing a fundamental, standard procedure to check for and eliminate problems exactly like this? Do we castigate the ignition manufacturer and keep the pilot blameless?

    Oh, let me mention something: That's not the way the story actually went. He didn't crash.

    When the engine stumbled, the pilot's first reaction was to check the ignition. He'd known others had had problems with that brand of electronic ignition. He'd left one old-style magneto in place specifically for having a backup with established reliability. He reached up, killed the electronic ignition, and the engine smoothed out again. He'd built the airplane, he'd made the decision to use the electronic ignition, and had trained for that contingency.

    Now, there are around 350,000 parts in a modern airliner. Even Airbus won't claim that not ONE of them will fail. So what the manufacturers do is publish procedures on how the pilot needs to respond to critical failures.

    The Operating Handbook for the Bowers Fly Baby is 24 pages long. I suspect that of the Boeing 737 or Airbus A320 is much, much longer. Yet it's still important that the pilot understand a wide variety of contingency conditions.

    So when an AOA vane fails...as has happened before, on several different types of airliners...there are procedures the pilot can use to revert to a manual control mode.

    This is the sort of thing that makes one look forward to seeing the NTSB report. But, of course, the NTSB is not the investigating agency in the Lion Air case.

    Ron Wanttaja
    Last edited by rwanttaja; 02-08-2019 at 12:06 AM.

  3. #13

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    Bill G, you wrote, "It fits a struggle between the pilots and the computer autopilot in the plane, pilots trying to pull up and computer pushing nose down" and I'm compelled to point out that no 737s have a stick pusher. Rather, Boeing included a new pitch trim enhancement on the 737 Max aircraft that uses electric trim to lower the nose. Prior generations of 737s already had a system known as "Speed Trim" that would do the same thing at low indicated airspeeds, but the heavier engines of the 737 Max aircraft required an additional system, the MCAS. The MCAS runs pitch down trim for up to 10 seconds. All that's needed to disable the system is to simply flip one toggle switch and that switch is within easy reach from either pilot seat.

    So in that sense, a malfunctioning MCAS acts like a runaway trim - what do you do with a runaway trim? Turn it off, right? The prior Lion Air crew flew nearly an entire flight with this anomaly.

    I do not forgive Boeing for failing to disclose the MCAS to the 737 Max operators in most countries including the U.S. - it absolutely should have been disclosed. And NO single point of failure should cause such chaos in the cockpit either.

    By the way, in this country, Southwest and American operate the same model as the accident aircraft - the 737-8Max.
    Last edited by CDS; 02-08-2019 at 10:24 AM.

  4. #14

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    Quote Originally Posted by Bill Greenwood View Post
    DRGT if you think the report is "incorrect" then what is not factual about it? By the way, I have no connection to Boeing, financial or personal, nor of course to that airline
    Do you have any?
    I made 2 distinct points in my post: 1) I doubt the news report was 100% factual. We will wait until there is a final report until we judge the quality of that report. If it turns out the news report was spot on, I will tip my hat to you and NBC. 2) I speculated even if the report is correct, it is a big so what to most of the readers on this forum. Maybe one or two of you will sell/buy airline stock, but it is hard for me to imagine that there is any significant action most of us will take.

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    CDS, when I wrote the summary of the report. I didnt have a tech editor to try to make it foolproof to any reader such as yourself who's looking for a flaw in my writing, instead of any flaw in the way the plane was made or the training or lack of it given to the pilots. But since you want to be that picky about it, lets get to it. I never wrote that this plane nor any other had a "stick pusher", Im not an airline pilot, dont know this much detail. So if you see a major difference in what you wrote. ""a new pitch trim enhancement that uses electric trim to lower the nose". from what I wrote. then you should be a lawyer for Lion Air, and or Boeing. To me, as as simple pilot of about 4 decades, if the trim or the computer or softwear or stick push or whatever, if trying to lower the nose, while the pilots are trying to raise it that is a problem, especially if the pilots arent really aware of this tendency or the cure, which may be as easy as you say. But your theory of how simple and easy the fix is, doen't jibe with THE FACTUAL DATA FROM THE BLACK BOX WHICH SHOWS THEY HAD MAJOR PITCH PROBLEMS AND FINALLY CRASHED.
    DRGT, I have no doubt that you would be unlikely to change any of your thinking or prejudices by anything I wrote or any accident report. And my post had nothing to do with anyone buying or selling stock.

  6. #16

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    Quote Originally Posted by Bill Greenwood View Post
    CDS, when I wrote the summary of the report. I didnt have a tech editor to try to make it foolproof to any reader such as yourself who's looking for a flaw in my writing, instead of any flaw in the way the plane was made or the training or lack of it given to the pilots. But since you want to be that picky about it, lets get to it. I never wrote that this plane nor any other had a "stick pusher", Im not an airline pilot, dont know this much detail. So if you see a major difference in what you wrote. ""a new pitch trim enhancement that uses electric trim to lower the nose". from what I wrote. then you should be a lawyer for Lion Air, and or Boeing. To me, as as simple pilot of about 4 decades, if the trim or the computer or softwear or stick push or whatever, if trying to lower the nose, while the pilots are trying to raise it that is a problem, especially if the pilots arent really aware of this tendency or the cure, which may be as easy as you say. But your theory of how simple and easy the fix is, doen't jibe with THE FACTUAL DATA FROM THE BLACK BOX WHICH SHOWS THEY HAD MAJOR PITCH PROBLEMS AND FINALLY CRASHED.
    DRGT, I have no doubt that you would be unlikely to change any of your thinking or prejudices by anything I wrote or any accident report. And my post had nothing to do with anyone buying or selling stock.
    Bill, I was simply correcting a flaw introduced by the media (not criticizing you). NO 737 has a stick pusher, so to state that the computer pushes the airplane nose down is not correct; in this case, it's an important distinction as other airliners DO have a stick pusher*.

    If someone - including the media - made a factual error about your Spitfire, would you want to correct that error? If someone said or wrote that your Spitfire had an Allison engine, you'd correct that, wouldn't you? If I made that error and you corrected me, I'd thank you for that correction.

    As to your next point. If the MCAS fault made the airplane unflyable, how did the airplane get to Jakarta in the first place? The fault occurred on the prior flight, too, eh? The 737 Max's MCAS fault behaves just like a runaway trim - how do you handle that? Turn the trim off, right?

    I do agree that Boeing made two huge mistakes with the 737 Max aircraft (and for the record, yes, I've flown one). They didn't disclose the MCAS system to most operators and they allowed a single point of failure to cause the scenario that lead to the Lion Air tragedy. I suspect that the MCAS will be changed to at least include both alpha vane inputs.


    *Which is "worse" - a trim system that trims the airplane nose down or a stick pusher? As I recall, the 727 had a stick pusher, but I enjoyed flying that airplane somewhat more than the 737.
    Last edited by CDS; 02-09-2019 at 04:14 PM.

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