From FAA's 2004 Instrument Procedures Handbook, chapter 5:
[...]
The weather conditions encountered in CAT III opera-
tions range from an area where visual references are
adequate for manual rollout in CAT IIIa, to an area
where visual references are inadequate even for taxi
operations in CAT IIIc. To date, no U.S. operator has
received approval for CAT IIIc in OpsSpecs.
[...]

But I heard that airlines are not only authorized, but required
to do an auto-land every so often. Am I missing something here?

Andrey


Jim Carter wrote:

-----Original Message-----
From: Andrey Serbinenko ]
Posted At: Sunday, August 06, 2006 2:42 PM
Posted To: rec.aviation.ifr
Conversation: CAT IIIC minimums
Subject: CAT IIIC minimums

A question: the landing minimums section for ILS CAT-III approaches
may have separate lines for A, B, and C. In some cases the C line
has an "NA" for visibility, and on some other plates the whole C
line is missing. So, what's the difference? Does "NA" mean "not
authorized", i.e. CAT-IIIC cannot be used?

Thanks!


Andrey

Can you give us a particular plate or approach to reference please?