"Robert M. Gary" wrote in message
...
On Jul 22, 7:04 pm, "BT" wrote:
This has been discussed during various IFR courses and refreshers.. I'm
running on old memory here.
For a Part 91 operation it is not enforceable. The tower has no way of
knowing what the pilots in-flight visibility is at the approach end of
the
runway.
I have seen pure VFR on one end for 2,000ft of a 10,000 ft runway.. with
the
other parts of the airport the fog so thick you could not see the lines
to
taaxi.

Me too. Althought I believe if RVR is reported, that is enforceable.
Otherwise, my understanding is the same as yours. Only those in the
cockpit know flight vis.

Not even then, really. RVR vis data is not archived for one thing so all
you really have to go on is a controller's memory to begin with. For
another, if it's a Cat I RVR, there's only one sensor located at center
field. That means it could be as far away as a mile or more on a long
runway.

For Part 135 and other operations, the pilot cannot even begin the
approach
for a "look see" if the visibility and ceiling are reported as less than
that required for the approach.

Yes, but if the reported wx degrades after crossing the FAF they can
continue the approach. So perhaps if they land with reported vis below
mins they could be busted? That doesn't sound right either.

One thing you have to understand is there are a few controllers who enjoy
busting pilots, but they are in the minority. The vast majority will give
the pilot the benefit of the doubt to the extent they are able. However
this discretion is being slowly removed at many facilities due to a
nationwide crackdown.