In article ,
"O. Sami Saydjari" wrote:
So, my question becomes, at what point do you abort the attempt to go
visual and transition to an IFR approach.

If you get as low as the controller can get you and you still can't see
the airport. Just say something like, "negative contact, request ILS"
and the controller will give you a new clearance for the instrument
approach.

Say, you have a GPS and ATC
cleared you down to 2000 ft AGL and you are 10 miles from the airport.
Do you continue at that altitude to the airport until you are right on
top of it (controller permitting), notice that you are still not out of
the clouds, and then ask for an IFR approach at that point?

That sounds like one reasonable way of doing it. Of course, it pays to
get whatever weather info is available. If there's an AWOS/ASOS that's
reporting 1500 overcast and the controller says he can only get you down
to 2000, there's not much point.

Just trying
to see how the transition from "going for visual" to "err, no can
do...need an instrument" happens. Does the controller force the
decision at some distance out?

It's not the job of the controller to tell you what to do. You make
requests and as long as he's able to, he'll issue you clearances.

If you're north of the airport and instrument approach is the ILS-36,
you've got to go over the top of the airport to get to the appoach.
Assuming no conflicting traffic, you could ask the controller to vector
you onto downwind for 36 at the MIA to see if you can see the runway.
If you do, you can request the visual (or contact) right then and there.
If you don't see anything, you just keep going out to the IAF and fly
the approach normally.

On the other hand, if you're already pretty much lined up for an
instrument approach, you really don't gain anything by asking for a
visual.