Peter Clark wrote:

You don't need CAT IIIc for autoland. Cat IIIa is sufficient. I'm
sure one of the airline drivers will chime in - ceiling/visibility
ignored for a moment, can't you autoland off a normal CAT I ILS if you
so desire? It's the same LOC/GS as the CAT III beam, right? They
just flight and obstacle check to a greater tolerance for the CAT III
authorization?


It depends upon an airline's ops specs and flight ops policy.
Autolanding on a non-CAT III ILS does not assure containment on the
runway, thus the weather better be sufficient to see if things are not
working out.