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Perhaps Boeing should take a step back and reconsider their drive for "safety automation" given that it didn't exactly work out so well the last time: https://w

Perhaps Boeing should take a step back and reconsider their drive for "safety automation" given that it didn't exactly work out so well the last time: https://www.nakedcapitalism.com/2018/11/boeing-crapification-lion-air-crash.html https://www.nakedcapitalism.com/2018/11/boeing-crapification...

sitkack 8y ago
I am going to excerpt a section because this needs to be known. > The short version of the story is that Boeing had implemented a new “safety” feature that operated even when its plane was being flown manually, that if it went into a stall, it would lower the nose suddenly to pick airspeed and fly normally again. However, Boeing didn’t tell its buyers or even the FAA about this new goodie. It wasn’t in pilot training or even the manuals. But even worse, this new control could force the nose down so far that it would be impossible not to crash the plane. And no, I am not making this up. From the Wall Street Journal: Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month’s fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots. The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 models—intended to help cockpit crews avoid mistakenly raising a plane’s nose dangerously high—under unusual conditions can push it down unexpectedly and so strongly that flight crews can’t pull it back up. Such a scenario, Boeing told airlines in a world-wide safety bulletin roughly a week after the accident, can result in a steep dive or crash—even if pilots are manually flying the jetliner and don’t expect flight-control computers to kick in. See also, https://www.aviationtoday.com/2018/11/20/lion-air-boeing-737-investigation-places-flight-controls-focus/ https://www.aviationtoday.com/2018/11/20/lion-air-boeing-737... Indonesian National Transportation Safety Committee (KNKT) officials investigating the Oct. 29 crash initially attributed the most likely cause of the accident to erroneous angle-of-attack (AOA) data. Now those same officials, and several airline pilot unions, claim the flight crew operations manual did not contain critical information for pilots regarding the maneuvering characteristics augmentation system (MCAS) designed to prevent the 737 MAX from stalling.
- sokoloff 8y ago
  That system (MCAS) operates by driving the stabilizer trim. There is, in all models of 737, a QRH checklist exists that, when/if correctly followed, would have stopped the trim runaway that started the apparent chain of events leading to the loss of Lion Air 610. NNC 9.1 in this document: http://jira.icesoft.org/secure/attachment/21680/qrh%20rev36%20-800%2027k.pdf http://jira.icesoft.org/secure/attachment/21680/qrh%20rev36%... Note that items above the dashed line are "memory items" (critical items that the crew memorizes and executes before referencing the checklists). Note also that this is the only non-normal-checklist for flight controls that includes memory items. It's not like we're asking the crew to memorize and react to thousands of things from memory. Stabilizer trim is important on aircraft of nearly every size. To get a 737 type rating, you had to have been familiar with that checklist and very likely to have demonstrated it in training. I know the media is trying to hang LA610 on Boeing. As a pilot, I think a substantial amount of the blame [probably the majority of it] is going to land in the cockpit, particularly if it turns out they didn't follow that checklist. (It's not important why the stabilizer is being driven in an uncommanded and undesirable fashion, just that the crew stops it.)

sitkack 8y ago

I am going to excerpt a section because this needs to be known. > The short version of the story is that Boeing had implemented a new “safety” feature that operated even when its plane was being flown manually, that if it went into a stall, it would lower the nose suddenly to pick airspeed and fly normally again. However, Boeing didn’t tell its buyers or even the FAA about this new goodie. It wasn’t in pilot training or even the manuals. But even worse, this new control could force the nose down so far that it would be impossible not to crash the plane. And no, I am not making this up. From the Wall Street Journal: Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month’s fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots. The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 models—intended to help cockpit crews avoid mistakenly raising a plane’s nose dangerously high—under unusual conditions can push it down unexpectedly and so strongly that flight crews can’t pull it back up. Such a scenario, Boeing told airlines in a world-wide safety bulletin roughly a week after the accident, can result in a steep dive or crash—even if pilots are manually flying the jetliner and don’t expect flight-control computers to kick in. See also, https://www.aviationtoday.com/2018/11/20/lion-air-boeing-737-investigation-places-flight-controls-focus/ https://www.aviationtoday.com/2018/11/20/lion-air-boeing-737... Indonesian National Transportation Safety Committee (KNKT) officials investigating the Oct. 29 crash initially attributed the most likely cause of the accident to erroneous angle-of-attack (AOA) data. Now those same officials, and several airline pilot unions, claim the flight crew operations manual did not contain critical information for pilots regarding the maneuvering characteristics augmentation system (MCAS) designed to prevent the 737 MAX from stalling.

sokoloff 8y ago
That system (MCAS) operates by driving the stabilizer trim. There is, in all models of 737, a QRH checklist exists that, when/if correctly followed, would have stopped the trim runaway that started the apparent chain of events leading to the loss of Lion Air 610. NNC 9.1 in this document: http://jira.icesoft.org/secure/attachment/21680/qrh%20rev36%20-800%2027k.pdf http://jira.icesoft.org/secure/attachment/21680/qrh%20rev36%... Note that items above the dashed line are "memory items" (critical items that the crew memorizes and executes before referencing the checklists). Note also that this is the only non-normal-checklist for flight controls that includes memory items. It's not like we're asking the crew to memorize and react to thousands of things from memory. Stabilizer trim is important on aircraft of nearly every size. To get a 737 type rating, you had to have been familiar with that checklist and very likely to have demonstrated it in training. I know the media is trying to hang LA610 on Boeing. As a pilot, I think a substantial amount of the blame [probably the majority of it] is going to land in the cockpit, particularly if it turns out they didn't follow that checklist. (It's not important why the stabilizer is being driven in an uncommanded and undesirable fashion, just that the crew stops it.)