Steven P. McNicoll wrote:
Even when flying a visual approach under IFR the pilot still must
cancel upon landing and ATC can't clear the next acft in until that
cancellation is received, right? (uncontrolled field)


Wrong. ATC can clear the next aircraft using visual separation before the
first one cancels.

I talked to my ATC pal tonight about this and he referenced the 7110.
You're absolutely right about the visual approach. The scenario I had
in mind was an uncontrolled field just above minimums (no visual
approach possible). In that case ATC can't clear another acft for an
approach until the previous acft has canceled as they can't provide
separation if the first acft is on another frequency. That was what I
meant by one in, one out.