CAT IIIC minimums

Jim Carter wrote:





So contrary to what others have suggested, the NA does not mean “not
authorized”; rather, it means “not applicable”.

Where do you get that idea? From an incorrectly printed Jepp chart perhaps?

Check FAR 97.3, and I quote:

(n) "NA" means not authorized.

Peter Clark wrote:

You don't need CAT IIIc for autoland. Cat IIIa is sufficient. I'm
sure one of the airline drivers will chime in - ceiling/visibility
ignored for a moment, can't you autoland off a normal CAT I ILS if you
so desire? It's the same LOC/GS as the CAT III beam, right? They
just flight and obstacle check to a greater tolerance for the CAT III
authorization?


It depends upon an airline's ops specs and flight ops policy.
Autolanding on a non-CAT III ILS does not assure containment on the
runway, thus the weather better be sufficient to see if things are not
working out.

-----Original Message-----

From: Gary Drescher ]

Posted At: Monday, August 07, 2006 8:13 AM

Posted To: rec.aviation.ifr

Conversation: CAT IIIC minimums

Subject: CAT IIIC minimums



"Jim Carter" wrote in message

news:001c01c6b9e5$41b26ee0$4001a8c0@omnibook6100.. .

The lowest authorized ILS minimums, with all required ground and
airborne

systems components operative, are

....

I found ... on page 5-49 of the Instrument Procedures Handbook at




http://www.faa.gov/library/manuals/a...ocedures_handb
oo

k/



....



No, NA means "not authorized". See


http://www.naco.faa.gov/content/naco..._IAP_Intro.pdf
,

p.

53. (Also, Jeppesen's Instrument/Commercial Manual, Appendix B, lists
NA

as

an abbreviation for "not authorized".)



The material you cited above is entirely consistent with the "not

authorized" meaning.





Gary,

I pulled up the pdf file you supplied as reference and had adobe
search for the "not authorized" phrase. There is only one instance found
under the Alternate Minimums paragraph on page 53: "If NA appears,
alternate minimums are not authorized due to unmonitored facility or
absence of weather reporting service." I did not reference Jeppesen
because they are not the authority for this information.



Could this be a case of NA meaning one thing for CAT IIIc and
something else for other purposes? It probably would have made more
sense if the visibility requirement was shown as not required or
inapplicable.



How could an approach be authorized if the visibility requirement
is "not authorized"?





There is no CAT IIIc approach into JFK for runway 4R



Sorry, can you say how you arrived at that conclusion?





There is no CAT IIIc minima listed on the plate even though there is CAT
IIIa and b.





which is why it is not listed on the plate.



Couldn't it be unlisted because there are no DA or RVR limitations to

list?



--Gary



No, then it would be an unpublished approach wouldn't it? The definition
of CAT IIIc is zero/zero (more explicit language is found in my original
reference). The approach would be listed on the JFK plate if it was
approved and published. The EWS plate lists all three approach minima.

-----Original Message-----
From: Sam Spade ]
Posted At: Monday, August 07, 2006 8:27 AM
Posted To: rec.aviation.ifr
Conversation: CAT IIIC minimums
Subject: CAT IIIC minimums

Jim Carter wrote:


So contrary to what others have suggested, the NA does not mean "not
authorized"; rather, it means "not applicable".

Where do you get that idea? From an incorrectly printed Jepp chart
perhaps?

Check FAR 97.3, and I quote:

(n) "NA" means not authorized.

Please notice the quote I pasted from the TERPS manual. Also, please
read the notes on the pages I originally referenced. They state that
there is no applicable RVR (visibility) requirement for CAT IIIc. They
also state that CAT IIIc is operation with visibility unsuitable for
taxi.

How could an approach be authorized yet have the visibility requirements
part of it be not authorized? When you take that NACO plate into
consideration in light of the TERPS manual, not applicable is a
reasonable conclusion.

Jim Carter wrote:


-----Original Message-----
From: Sam Spade ]
Posted At: Monday, August 07, 2006 8:27 AM
Posted To: rec.aviation.ifr
Conversation: CAT IIIC minimums
Subject: CAT IIIC minimums

Jim Carter wrote:


So contrary to what others have suggested, the NA does not mean "not
authorized"; rather, it means "not applicable".

Where do you get that idea? From an incorrectly printed Jepp chart
perhaps?

Check FAR 97.3, and I quote:

(n) "NA" means not authorized.


Please notice the quote I pasted from the TERPS manual. Also, please
read the notes on the pages I originally referenced. They state that
there is no applicable RVR (visibility) requirement for CAT IIIc. They
also state that CAT IIIc is operation with visibility unsuitable for
taxi.

How could an approach be authorized yet have the visibility requirements
part of it be not authorized? When you take that NACO plate into
consideration in light of the TERPS manual, not applicable is a
reasonable conclusion.

But, NA has a regulatory definition for Part 97 standard instrument
approach procedures. There is no provision for conjecture when NA is
issued under Part 97.

CAT IIIc is not authorized for any operator at the present time. The
concept is that it *may* be authorized at some future time, provided
something such as enhanced vision systems become good enough to taxi
without any visibility.

The FAA, being the way it is, had to have a building block of minima
that went "all the way" so to speak, when they implemented the Category
III program in the 1970s.

They like having goals, even unachievable goals. ;-)

-----Original Message-----
From: Sam Spade ]
Posted At: Monday, August 07, 2006 8:59 AM
Posted To: rec.aviation.ifr
Conversation: CAT IIIC minimums
Subject: CAT IIIC minimums

....

The FAA, being the way it is, had to have a building block of minima
that went "all the way" so to speak, when they implemented the
Category
III program in the 1970s.

They like having goals, even unachievable goals. ;-)

Then why didn't they produce the same building block of minima for
Newark?

There is a range of visibility between RVR 06 and RVR 00 that would be
below CAT IIIb, yet would allow for properly equipped aircraft, flown by
properly trained crews to execute approaches, and still provide
sufficient visibility for taxi operations.

Is your point that the CAT IIIc approach into JFK is not authorized at
all?

"Jim Carter" wrote in message
news:000801c6ba26$9bd59ff0$4001a8c0@omnibook6100.. .
Could this be a case of NA meaning one thing for CAT IIIc and
something else for other purposes?

No. In addition to the inherent implausibility of such an inconsistency, Sam
has pointed out that FAR 97.3n explicitly defines NA to mean "not
authorized" with regard to IAPs.

How could an approach be authorized if the visibility requirement is "not
authorized"?

I don't follow. If "NA" appears in the IIIC line, it means a IIIC approach
is not authorized.

Couldn't it be unlisted because there are no DA or RVR limitations to
list?

No, then it would be an unpublished approach wouldn't it?

Not necessarily. The IIIC approach is published by virtue of the approach
plate that is labeled "CAT III". By definition, CAT III comprises IIIA,
IIIB, and IIIC. There's a section of the plate that lists visibility
limitations for the subcategories; the omission of IIIC from that section
means that there is no visibility limitation for IIIC.

The EWS plate lists all three approach minima.

Assuming that's a typo for EWR (I find no EWS), the plate for ILS 4R CAT III
does not list minima for IIIC; rather, it says the IIIC approach is not
authorized (NA). http://www.naco.faa.gov/d-tpp/0608/00285I4RC3.PDF

--Gary

ignored for a moment, can't you autoland off a normal CAT I ILS if you
so desire? It's the same LOC/GS as the CAT III beam, right? They

If I remember correctly, the glide slope reception and usability for
vertical guidance are only guaranteed above DA for the approach. So,
I'd assume CAT I and CAT II beams don't officially reach the surface
of the runway.

Andrey


just flight and obstacle check to a greater tolerance for the CAT III
authorization?


On Mon, 07 Aug 2006 04:37:55 +0000, Andrey Serbinenko
wrote:

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?

Jim Carter wrote:

-----Original Message-----
From: Sam Spade ]
Posted At: Monday, August 07, 2006 8:59 AM
Posted To: rec.aviation.ifr
Conversation: CAT IIIC minimums
Subject: CAT IIIC minimums


...

The FAA, being the way it is, had to have a building block of minima
that went "all the way" so to speak, when they implemented the

Category

III program in the 1970s.

They like having goals, even unachievable goals. ;-)


Then why didn't they produce the same building block of minima for
Newark?

There is a range of visibility between RVR 06 and RVR 00 that would be
below CAT IIIb, yet would allow for properly equipped aircraft, flown by
properly trained crews to execute approaches, and still provide
sufficient visibility for taxi operations.

Is your point that the CAT IIIc approach into JFK is not authorized at
all?


My point is: CAT III c is supposed to be included on all CAT III charts
with the entry "NA" (Not Authorized). Where a CAT III chart does not
have a line for CAT IIIc, it is not in compliance with FAA policy.

Andrey Serbinenko wrote:

ignored for a moment, can't you autoland off a normal CAT I ILS if you
so desire? It's the same LOC/GS as the CAT III beam, right? They


If I remember correctly, the glide slope reception and usability for
vertical guidance are only guaranteed above DA for the approach. So,
I'd assume CAT I and CAT II beams don't officially reach the surface
of the runway.

Andrey

The G/S is not used for Autoland below 100 feet, or so. It is all radar
altimetry and computer logic starting at 150 feet, when the system goes
from autoland tracking to autoland align.