PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 2nd Jul 2019, 20:36
  #954 (permalink)  
Europa01
 
Join Date: Dec 2014
Location: Somerset
Posts: 40
Likes: 0
Received 0 Likes on 0 Posts
Cutout Switches

Originally Posted by Alchad
Sorry, a dumb question but electric circuits are a black art to me. I've seen this, or a similar diagram before, and am aware of all the comments that the two switches now peform an identical function. If that is the case, what is the function of the circuit 8 - 9 in the S272 Stab Trim Cutout Switch?

Thanks

Alchad
If I read 27-41 correctly in Smythe's #951 post, the 8 -9 contacts are the FCC (and hence MCAS) route direct to the Eaton stab motor. As has been discussed this item is clearly more than just a motor and very little information about its architecture seems to be available. Terms such as 'processor based' could mean anything but are probably chosen carefully and probably don't mean microprocessor controlled. In my industry (nuclear) there are rigorous technical protocols for assessing and verifying embedded software on safety critical equipment and I'd be astonished if there is not something very similar in aerospace.
Europa01 is offline