PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 5th Sep 2019, 20:40
  #2198 (permalink)  
Peter H
 
Join Date: Jun 2008
Location: Cambridge UK
Posts: 162
Originally Posted by infrequentflyer789 View Post
How is this different to the aft column cutout switch which is already there?

I mean, yes, great idea, doesn't need any training because it's how the a/c did work and was understood to work anyway, but apparently MCAS can't do its "job" with that switch in the loop, so it was bypassed.

Now, some of us might think that bypassing that switch should have been a red flag, that it wasn't put there in the first place just to use up some spare contacts, and that if you have to remove (or bypass) a safety device that's been there for decades without causing any issue in order to meet a safety certification, then you're doing it wrong... but from where we are now, putting it back would appear to be a non-starter.
My emphasis.

It's different because:
- MCAS trimming is disabled by an additional force-operated switch which "is automatically hardware-toggled by emergency-level pulling on the stick".
- while non-MCAS trimming is still disabled by the original cutout switch.
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