3 ms·

Or repurpose the existing second trim cutout switch... (AFAIK there are two, that used to serve different purposes, and are now both left in to keep the same ty

Or repurpose the existing second trim cutout switch... (AFAIK there are two, that used to serve different purposes, and are now both left in to keep the same type rating).

toast0 6y ago
Yes! If this was available, at least the second crash seemed likely preventable given the timeline of events. I didn't read the timeline for the first one.
- salawat 6y ago
  Relevant article: https://www.seattletimes.com/business/boeing-aerospace/boeing-altered-key-switches-in-737-max-cockpit-limiting-ability-to-shut-off-mcas/ https://www.seattletimes.com/business/boeing-aerospace/boein... That would allow a pilot to put the plane in a configuration for which it is not certified to transport passengers, however, and the triggering thereof should always be deemed an emergency if we're going to take our regulations with any level of seriousness.
  - toast0 6y ago
    That article has opposing viewpoints on if it would be a good idea. But, imagine if the switches were as before --- the left turns off automation control of electric trim, and the right turns off all electric trim. In that case Boeing's notice for what to do in case of MCAS failure would be turn off the left switch and then they'd have advice about how immediate the need to land is. As opposed to their notice which was insufficient for Ethiopia Air pilots because they weren't able to trim the stabilizer manually and tried reenabling electric trim and MCAS continued to be broken. Hopefully the MCAS changes described will be sufficient to prevent it from causing more crashes, and Boeing has republished a procedure to gain manual control by easing off the yoke temporarily, but it still seems to me that providing electric trim without automation input, as was available before (but never suggested to be used) would provide an additional tool for pilots in exceptional circumstances.

Or repurpose the existing second trim cutout switch... (AFAIK there are two, that used to serve different purposes, and are now both left in to keep the same type rating).

toast0 6y ago

Yes! If this was available, at least the second crash seemed likely preventable given the timeline of events. I didn't read the timeline for the first one.

salawat 6y ago
Relevant article: https://www.seattletimes.com/business/boeing-aerospace/boeing-altered-key-switches-in-737-max-cockpit-limiting-ability-to-shut-off-mcas/ https://www.seattletimes.com/business/boeing-aerospace/boein... That would allow a pilot to put the plane in a configuration for which it is not certified to transport passengers, however, and the triggering thereof should always be deemed an emergency if we're going to take our regulations with any level of seriousness.
- toast0 6y ago
  That article has opposing viewpoints on if it would be a good idea. But, imagine if the switches were as before --- the left turns off automation control of electric trim, and the right turns off all electric trim. In that case Boeing's notice for what to do in case of MCAS failure would be turn off the left switch and then they'd have advice about how immediate the need to land is. As opposed to their notice which was insufficient for Ethiopia Air pilots because they weren't able to trim the stabilizer manually and tried reenabling electric trim and MCAS continued to be broken. Hopefully the MCAS changes described will be sufficient to prevent it from causing more crashes, and Boeing has republished a procedure to gain manual control by easing off the yoke temporarily, but it still seems to me that providing electric trim without automation input, as was available before (but never suggested to be used) would provide an additional tool for pilots in exceptional circumstances.