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Old 28th Mar 2019, 18:56
  #2685 (permalink)  
GordonR_Cape
 
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Originally Posted by MarcK
Stuck bits are more likely an optical encoder error in the AOA vane, not a software error.
Wow! You have just reminded me of something that caused us a great deal of trouble, on a completely different different piece of equipment. Our electric gate motor closing mechanism used to give problems, due to contamination of the digital encoding optical sensor (a glorified rotary counter).

I know the AOA is completely different sensor, but in the context of this thread that might consistently produce a consistent bit-flip (20 degrees) error.

Originally Posted by Maninthebar
How likely is that in two different aircraft (or maybe more if we take into account NASA reports)? Is that a possible QC issue at manufacture?

(I realise that I have jumped to more conclusions than a champion pole vaulter)
Possible QC error that only reveals after a few months service?

In our case it was it was an oil leak from the bearing that got onto/contaminated the optical sensor.
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