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Lion Air 737-Max missing, presumed down in the sea near CGK (Jakarta)

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  • Evan
    replied
    Originally posted by ATLcrew View Post
    I don't think that was the MAIN selling point of the airplane, but carry on.
    The main selling point of the -MAX was “Whoa... wait! Don’t buy the A320NEO! We can get those LEAP engines on the same airplane you are already using (somehow).” It was fleet commonality and deep discounts. I see cockpit commonality as part of fleet commonality. Not having to type-transition pilots was part of that selling point.

    Seriously, with acquisition and operating costs being essentially the same, why else would you choose the 737-MAX over the A320NEO?

    Leave a comment:


  • ATLcrew
    replied
    Originally posted by Black Ram View Post
    I think as it stands now, MCAS was needed for certification. We can debate how essential the system is (or was), but the 737 MAX was certified as just another 737, for which it needed to feel just like the old 737 models. That new training you mentioned that you expect to see implemented - the lack of such training was a main selling point of this airplane.
    I don't think that was the MAIN selling point of the airplane, but carry on.

    Leave a comment:


  • ATLcrew
    replied
    Originally posted by Black Ram View Post
    The flaw in whose logic? I've been waiting to read real arguments from the likes of BoeingBobby, but instead I see mostly jabs and attacks at anyone who points out the seriousness of the MCAS mess and how it relates to the two MAX crashes. And in my book, this is flawed logic - saying ambiguous stuff about the author of a post instead of constructing an argument that debates what is being said in the post.
    Welcome to the internet in general and to aviation fora specifically.

    Leave a comment:


  • Black Ram
    replied
    Originally posted by Schwartz View Post
    That logic is predicated on MCAS being considered an essential safety system (vs a safety hazzard as it clearly was initially implemented). I have a feeling it is not considered such. I believe it was added to make it feel more like the old models. More sensors increases the odds of a failure and depending on the nature of typical failures for this type of sensor, perhaps it isn't all that unlikely that 2 fail close together.
    I think as it stands now, MCAS was needed for certification. We can debate how essential the system is (or was), but the 737 MAX was certified as just another 737, for which it needed to feel just like the old 737 models. That new training you mentioned that you expect to see implemented - the lack of such training was a main selling point of this airplane. And to be able to be certified without such training, MCAS was needed for safety. So it would seem pretty essential when it comes to safety, unless the training is changed, which changes the acquisition/operation costs for the airlines.

    Now I don't see how more sensors leads to a system that is more prone to failure. More sensors equals more redundancy, and having redundant systems has been the safety standard in aviation for a long time, as opposed to having systems with only single components. Whether more sensors leads to more failure can be determined by studying different airplanes and comparing the frequency of failures they experience. You have planes with 2 AoAs, with 3 AoAs and with 4 AoAs. And I was also saying 2 is insufficient for redundancy. Having a system with 2 AoAs designed in a way that the system can just act upon wrong data when one of those two AoAs has failed is straight criminal in my book.

    Leave a comment:


  • Black Ram
    replied
    Originally posted by Schwartz View Post
    Defend at all costs, please. Instead of waxing poetic why don't you point out the flaw in the logic? Or is that just rhetoric?
    The flaw in whose logic? I've been waiting to read real arguments from the likes of BoeingBobby, but instead I see mostly jabs and attacks at anyone who points out the seriousness of the MCAS mess and how it relates to the two MAX crashes. And in my book, this is flawed logic - saying ambiguous stuff about the author of a post instead of constructing an argument that debates what is being said in the post.

    Leave a comment:


  • Evan
    replied
    There is another possibility here. An AoA sensor disagree might be resolved by voting against the IR data, with the system choosing the a vane closest in alignment. If that works, the system could remain functional with a single vane. I wonder about that though, as a single degree of error can make a big difference where MCAS is designed to operate.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Why single?
    What is the probability of a double AoA vane failure?

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    Yet one, not so unforeseeable, single sensor failure removes it from functioning. And that’s ok?
    Why single?

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Even the NTSC's report on Lion AIr's accident (which is being praised by the industry at great) is ambiguous on the matter:
    It certainly isn’t ambiguous on what matters here: it was needed and is needed to certify the aircraft as safe to operate in commercial aviation. Yet one, not so unforeseeable, single sensor failure removes it from functioning. And that’s ok?

    Leave a comment:


  • BoeingBobby
    replied
    Originally posted by Cleveland.Spotter View Post
    Hello all! I'm glad there is a thread on this. I read the entire 322 page crash report and found a few things interesting I thought I would share.

    There were four main factors in the crash.

    1) Design Flaw (MCAS)
    2) Pilot Error
    3) Failure to Complete Maintenance-
    The report states that Lion Air failed to maintain an airworthy aircraft. There were known issues with the AOA sensors that were never addressed or fixed. These problems persisted for several flights leading up to the accident flight.
    4) Improper Maintenance Procedures-
    Lion Air outsourced their minimal maintenance done on the original problems with the AOA sensors to a third party company. This company implemented unapproved procedures and installed uncertified parts in order to "fix" the AOA sensors. This fix was nullified almost immediately as the repaired sensors quickly failed again. With the sensors failing again, as stated in #3, Lion Air neglected to put the aircraft in maintenance to fix the problem. Instead, flying a plane with paying passengers that was not airworthy.
    If the passengers were not paying, would it have been okay?

    Leave a comment:


  • 3WE
    replied
    Originally posted by Cleveland.Spotter View Post
    Hello all! I'm glad there is a thread on this. I read the entire 322 page crash report and found a few things interesting I thought I would share.

    There were four main factors in the crash.

    1) Design Flaw (MCAS)
    2) Pilot Error
    3) Failure to Complete Maintenance-
    The report states that Lion Air failed to maintain an airworthy aircraft. There were known issues with the AOA sensors that were never addressed or fixed. These problems persisted for several flights leading up to the accident flight.
    4) Improper Maintenance Procedures-
    Lion Air outsourced their minimal maintenance done on the original problems with the AOA sensors to a third party company. This company implemented unapproved procedures and installed uncertified parts in order to "fix" the AOA sensors. This fix was nullified almost immediately as the repaired sensors quickly failed again. With the sensors failing again, as stated in #3, Lion Air neglected to put the aircraft in maintenance to fix the problem. Instead, flying a plane with paying passengers that was not airworthy.
    Noted.

    Leave a comment:


  • Cleveland.Spotter
    replied
    Hello all! I'm glad there is a thread on this. I read the entire 322 page crash report and found a few things interesting I thought I would share.

    There were four main factors in the crash.

    1) Design Flaw (MCAS)
    2) Pilot Error
    3) Failure to Complete Maintenance-
    The report states that Lion Air failed to maintain an airworthy aircraft. There were known issues with the AOA sensors that were never addressed or fixed. These problems persisted for several flights leading up to the accident flight.
    4) Improper Maintenance Procedures-
    Lion Air outsourced their minimal maintenance done on the original problems with the AOA sensors to a third party company. This company implemented unapproved procedures and installed uncertified parts in order to "fix" the AOA sensors. This fix was nullified almost immediately as the repaired sensors quickly failed again. With the sensors failing again, as stated in #3, Lion Air neglected to put the aircraft in maintenance to fix the problem. Instead, flying a plane with paying passengers that was not airworthy.

    Leave a comment:


  • 3WE
    replied
    Originally posted by Gabriel View Post
    Even the NTSC's report on Lion AIr's accident (which is being praised by the industry at great) is ambiguous on the matter:
    Genuinely noted.

    Leave a comment:


  • Gabriel
    replied
    Even the NTSC's report on Lion AIr's accident (which is being praised by the industry at great) is ambiguous on the matter:

    During the preliminary design stage of the Boeing 737-8 (MAX), Boeing tests and analysis revealed that the addition of the LEAP-1B engine and associated nacelle changes was deemed likely to negatively affect the stick force per g (FS/g) characteristics required by 14 FAR 25.255 and the controllability and maneuverability requirements of 14 FAR 25.143(f). After the study of various options for addressing this issue, Boeing implemented aerodynamic changes as well as a stability augmentation function called the Maneuvering Characteristics Augmentation System (MCAS), as an extension of the existing Speed Trim System (STS), to improve aircraft handling characteristics at elevated angles of attack. The MCAS was needed in order to make the Boeing 737-8 (MAX) handling characteristics so similar to the NG versions that no simulator training was needed for type rating. It was also required so that the 737 MAX passed the certification that the pitch controls could not get lighter on the approach to stall. If the aircraft had substantially different pitch behavior, then there would be a simulator training requirement for the pilots.

    Leave a comment:


  • Schwartz
    replied
    Originally posted by Evan View Post
    You still don’t get it. This isn’t an aviation matter. It’s a matter of reckless management serving investor relations at the expense of safety. It’s a sort of industrial epidemic lately. And yes, the Times is a good place to find those truths.
    That is exactly what led us here. That doesn't mean everything being proposed is the same. This will NOT be status quo. Boeing is fundamentally a different company now, because they will border on bankruptcy and they have lost the trust of all their clients. This is catestrophic for investors at this point. They will demand any change to get them out of this, including a focus on safety.

    Leave a comment:

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