Originally Posted by
BrogulT
However, I'm not sure about your other statement and I've heard differing opinions on whether ATC can allow you to transit one area of their airspace under VFR, assuming that your entire transit route will be VMC, whilst the airport itself is reporting IMC.
Commenting in general here, I do it all the time.
The weather requirements for flying VFR in various classes of airspace are codified in 14 CFR 91.155, which states in part:
"§ 91.155 Basic VFR weather minimums.
(a) Except as provided in paragraph (b) of this section and § 91.157, no person may operate an aircraft under VFR when the flight visibility is less, or at a distance from clouds that is less, than that prescribed for the corresponding altitude and class of airspace in the following table: ..."
Notice the reg says "...
flight visibility is ..." and "
distance from clouds that is..." In the context of a pilot, "is" has only one meaning: that flight visibility experienced by the pilot at the time of observation. Likewise, in promulgating Amendment 91-262 to Part 91 in 2000, the FAA said:
"Flight visibility is also defined in 14 CFR section 1.1 and must be determined by a pilot from the cockpit while an aircraft is airborne." (65FR16113: Part 91 Amdt; No. 91-262, March 24, 2000)
In order for ATC to not require a SVFR, they need to know that you can maintain VFR (and thereby lessening their load and providing most of your own separation). Therefore, when you call for your transition, you need to advise them that you are, and can maintain VFR throughout your transition.
I do this on certain routes flying power lines in Northern California, and the first time I tried, I had to call the tower and explain this. If you know Barry Lloyd, he has a presentation on this very subject.