"Ron Rosenfeld" wrote in message
...

It has nothing to do with MSA. Basically, weather needs to be at least
1000/3, and the pilot needs to have the airport or an a/c to follow in
sight.

AIM 5-4-20. Visual Approach

a. A visual approach is conducted on an IFR flight plan and authorizes
a pilot to proceed visually and clear of clouds to the airport. The pilot
must have either the airport or the preceding identified aircraft in
sight.
This approach must be authorized and controlled by the appropriate air
traffic control facility. Reported weather at the airport must have a
ceiling at or above 1,000 feet and visibility 3 miles or greater. ATC may
authorize this type approach when it will be operationally beneficial.
Visual approaches are an IFR procedure conducted under IFR in visual
meteorological conditions. Cloud clearance requirements of 14 CFR Section
91.155 are not applicable, unless required by operation specifications.

This tells you when you can commence and continue the visual approach. I
think the question was more on the lines of the appropriate communications
with ATC when you think there's a visual in your future, but you can't be
certain yet.

-- David Brooks