76mike:
More comments are certainly welcome and appreciated, but I thought his answer would be of interest.
Note that your JFK ATC source was very careful in his wording; i.e., "From an ATC perspective..."
In other words from a traffic separation and close-in sequencing standpoint ATC has no issue with an aircraft departing the electronic guidance to line up with the runway at whatever point the pilot chooses. But, ATC has no authority to modify or amend a U.S. IAP issued under FAR Part 97, and your source obviously knows that.
From an IAP procedural standpoint, when to depart the electronic guidance on an offset, but straight-in IAP has always been vague. If the weather is good and ATC clears the pilot for a visual then the IAP is superceded. But, if the weather is good (more than reported 3 miles at the airport and clear of clouds, with runway in sight) then at what point can the pilot elect to depart the electronic guidance? The answer is: there is no regulatory or policy guidance on this at all.
But, what if the pilot is clear of the clouds and sees the runway but the airport weather report is less than 3 miles? That makes the JFK surface airspace IFR, so in that case the pilot cannot make any election to deviate from the IAP. But, obviously he does have to line up with the runway in sufficient time to make the line up safe. If the airport is IFR then that line up should not be done any sooner than deemed necessary by the pilot. That's my opinion based on having worked with this stuff for a very long time.
If you had a fed on the jump seat and the airport is officially IFR he could be quite critical about someone leaving the electronic guidance a "long way" out.
Clear as mud, right?
