I do also see some significant shortcomings of the fault isolation procedures and the SMYD BITE. Maintenance ran it three times without result. Fault logging in the air was also vacuous.
So the one cannot work comprehensively on ground because vanes show anything.
The other did not provide anything meaningful presumably because no reference from the other vane is used.
So an AoA error which is not SNA or out of rang but „only“ drift seems to be practically non-diagnoseable.
Or am I missing something?