Thanks Red. Lot's of good stuff in that Seattle Times article. This was my key takeaway :
Boeing’s safety analysis of the system assumed that “the pilots would recognize what was happening as a runaway and cut off the switches,” said the engineer. “The assumptions in here are incorrect. The human factors were not properly evaluated.”
Boeing assumed the pilots would respond to a MCAS hardover just as they would respond to their standard B 737 emergency procedure for [Stabilizer Runaway] which is probably a memory item that is practiced in simulator training. All Commercial Pilots of autopilot equipped aircraft are trained to recognize runaway nose down trim & respond by disengaging the autopilot & manually controlling the aircraft. Had the Lion Air pilots done that, they could have recovered, just like the crew on the previous flight did (thanks to the intercession of the deadheading pilot riding the cockpit who recognized the situation, interceded & switched off the MCAS switches on the center console).
Boeing's going to get hammered. The changes they are making would have prevented the Lion Air crash. Maybe the Ethopia Air crash as well -- too soon to know.
Either the pilot training changes
or the engineering changes proposed would likely have prevented Lion Air.
The pilot training changes would not have been that extensive -- just a better systems explanation in the Pilots Manual & a [CAUTION] alert in the Quick Reaction Handbook -- alerting MAX pilots that just overriding the MCAS with the trim switches or manually pushing the yoke forward, does not deactivate the MCAS, which will immediately raise the nose again until deactivated via the switches on the center console. The Lion Air pilots did not recognize that they were fighting with the MCAS & they generated, essentially, a pilot induced oscillation (PIO) as airspeed increased in their descent.
The engineering changes are a fail safe backup to prevent a situation which pilots will have to recognize & properly react to.
Boeing will be in trouble with the FAA for not updating the increased MCAS authority travel range which they incorporated during flight testing.
The fact that the stabilizer jackscrew recovered from the Ethopia Air plane indicated full throw, may call into question why MCAS commanded stabilizer travel was not limited by software.
Boeing is fortunate that the crashes were overseas with international carriers, limiting their liability. They can also cite pilot error, pilot training & maint error on Lion Air. We don't yet know how many of the US air carrier incidents reported to the FAA were similar, but it's possible that the pilot training of the US carriers prevented more crashes sooner.