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Here's the article I was thinking of, though I think it was originally either in seattletimes or WSJ. http://airsoc.com/articles/view/id/5d5143c7c4263ce96fd616

Here's the article I was thinking of, though I think it was originally either in seattletimes or WSJ. http://airsoc.com/articles/view/id/5d5143c7c4263ce96fd616b6/newly-stringent-faa-tests-spur-a-fundamental-software-redesign-of-boeing-s-737-max-flight-controls http://airsoc.com/articles/view/id/5d5143c7c4263ce96fd616b6/... Differen source. https://aviationweek.com/air-transport/software-fix-will-address-most-recent-max-issue https://aviationweek.com/air-transport/software-fix-will-add... The civillian trained test pilot lost it. The two military pilots did not.

WalterBright 5y ago
Thanks for the reference. I haven't seen this information before. "In one scenario, the bits chosen first told the computer that MCAS was engaged when it wasn’t. This had the effect of disabling the cut-off switches inside the pilot-control column, which normally stop any uncommanded movement of the horizontal tail if the pilot pulls in the opposite direction." The cutoff switches cannot be disabled on the airplane. "They flew the same fault scenario again, this time deliberately allowing the fault to run for some time before responding. This time, one of the three pilots didn’t manage to recover and lost the aircraft." That's kinda vague.
- salawat 5y ago
  https://www.seattletimes.com/business/boeing-aerospace/newly-stringent-faa-tests-spur-a-fundamental-software-redesign-of-737-max-flight-controls/ https://www.seattletimes.com/business/boeing-aerospace/newly... There it is! Knew it was in SeattleTimes somewhere! And lookout for the part about disabling cutoff switches, I think Dominic might have written that better, because I think he's talking about a safety function that was removed specifically for the MAX where hauling back hard on the yoke would stop trim commands in progress on NG airframes? MCAS required that that functionality not be ported forward to the MAX. This isn't disabling those cutouts though. Those are literally, like you said, a hard switch. >According to a second FAA source, it was the AEG pilot, representing a typical U.S. airline captain, who failed to recover the jet. There's the bit about the civilian test pilot.
  - WalterBright 5y ago
    Thanks. My experience is Aviation Week is a much more reliable source on technical topics. It's a hard switch for good reason. I hate "soft" switches that supposedly disable microphones. Phooey on that. BTW, on my hotrod I installed a hard switch to shut off the fuel pump, as well as an oil pressure switch that would shut it off. I have a g-switch to cut it off, too, but haven't gotten around to installing it.
- WalterBright 5y ago
  The article also does not mention the LA flight that survived the MCAS malfunction. Hence it always fall to me to mention it.
  - mannykannot 5y ago
    Flight into wind shear does not always lead to crashes. This does not mean that there is no need to train pilots for it.

WalterBright 5y ago

Thanks for the reference. I haven't seen this information before. "In one scenario, the bits chosen first told the computer that MCAS was engaged when it wasn’t. This had the effect of disabling the cut-off switches inside the pilot-control column, which normally stop any uncommanded movement of the horizontal tail if the pilot pulls in the opposite direction." The cutoff switches cannot be disabled on the airplane. "They flew the same fault scenario again, this time deliberately allowing the fault to run for some time before responding. This time, one of the three pilots didn’t manage to recover and lost the aircraft." That's kinda vague.

salawat 5y ago
https://www.seattletimes.com/business/boeing-aerospace/newly-stringent-faa-tests-spur-a-fundamental-software-redesign-of-737-max-flight-controls/ https://www.seattletimes.com/business/boeing-aerospace/newly... There it is! Knew it was in SeattleTimes somewhere! And lookout for the part about disabling cutoff switches, I think Dominic might have written that better, because I think he's talking about a safety function that was removed specifically for the MAX where hauling back hard on the yoke would stop trim commands in progress on NG airframes? MCAS required that that functionality not be ported forward to the MAX. This isn't disabling those cutouts though. Those are literally, like you said, a hard switch. >According to a second FAA source, it was the AEG pilot, representing a typical U.S. airline captain, who failed to recover the jet. There's the bit about the civilian test pilot.
- WalterBright 5y ago
  Thanks. My experience is Aviation Week is a much more reliable source on technical topics. It's a hard switch for good reason. I hate "soft" switches that supposedly disable microphones. Phooey on that. BTW, on my hotrod I installed a hard switch to shut off the fuel pump, as well as an oil pressure switch that would shut it off. I have a g-switch to cut it off, too, but haven't gotten around to installing it.
WalterBright 5y ago
The article also does not mention the LA flight that survived the MCAS malfunction. Hence it always fall to me to mention it.
- mannykannot 5y ago
  Flight into wind shear does not always lead to crashes. This does not mean that there is no need to train pilots for it.