First "real" hold (long)

"Barry" wrote
But as I replied to Dan Luke, neither the visibility at 100' nor the ground
visibility can replace the requirement for flight visibility to continue the
approach below DH.

But there is no flight visibility requirement for the ILS at PNS for
civil aircraft unless RVR is not reported. (Note that military
minimums DO specify flight visibility, but military aircraft are
excluded from the requirements of 91.175(c)) The minimums for the
approach are 321 MSL (DH) and 2400ft RVR. RVR is not the same thing
as flight visibility, and in fact every book of approach plates gives
a table for conversion from RVR minima to meteorological visibility,
to be used when RVR is not reported.

I've always interpreted 91.175(c)(2) to mean that you must
have the required visibility at all times below DH. Is there a
reference that contradicts this?

First, I'm not convinced this interpretation is correct. I'm aware of
no reference that contradicts OR supports it, but it is certainly not
in line with normal operating practice, even at the prefessional level
where scrutiny is high.

Second, even if it is correct, it would certainly apply only to those
approaches where minimum visibility, rather than minimum RVR, is
given. The fact that a conversion table is given (and the fact that
the numbers DO NOT convert directly - 2400 ft RVR becomes 1/2 sm
visibility, which is 2640 ft) certainly indicates that the terms are
not interchangeable.

Michael