CAT IIIC minimums [Archive]

Andrey Serbinenko

August 7th 06, 01:44 AM

OK, then why do they include IIIC line with an "NA" on some
plates and omit it altogether on others?

Sam Spade wrote:
> Andrey Serbinenko wrote:
>> 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
>
> NA indeed means Not Authorized.

Jim Carter[_1_]

August 7th 06, 01:50 AM

> -----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?

Andrey Serbinenko

August 7th 06, 04:36 AM

Sure. Hmm... what do we have here... NACO north-east... Okay, here:
Newark Liberty, KEWR, ILS RWY 4R (CAT III) lists visibility
S-ILS 4R for CAT IIIC as NA.
New York JFK, KJFK, ILS RWY 4R (CAT III) lists visibilities
S-ILS 4R for CAT IIIA and CAT IIIB, but no CAT IIIC line there.

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?
>

Andrey Serbinenko

August 7th 06, 05:37 AM

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[_1_]

August 7th 06, 06:49 AM

> -----Original Message-----

> From: Andrey Serbinenko ]

> Posted At: Sunday, August 06, 2006 10:36 PM

> Posted To: rec.aviation.ifr

> Conversation: CAT IIIC minimums

> Subject: Re: CAT IIIC minimums

>

..

> >

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

> >

Okay, I have an answer and a reference (highlights are mine).

The lowest authorized ILS minimums, with all required ground and
airborne systems components operative, are

.. Category I - Decision Height (DH) 200 feet and Runway Visual Range
(RVR) 2,400 feet (with touchdown zone and centerline lighting, RVR 1800
feet),

.. Category II - DH 100 feet and RVR 1,200 feet,

.. Category IIIa - No DH or DH below 100 feet and RVR not less than 700
feet,

.. Category IIIb - No DH or DH below 50 feet and RVR less than 700 feet
but not less than 150 feet, and

.. Category IIIc - No DH and no RVR limitation.

NOTE: Special authorization and equipment are required for Category II
and III.

I found the above on page 5-49 of the Instrument Procedures Handbook at
http://www.faa.gov/library/manuals/aviation/instrument_procedures_handbo
ok/

So contrary to what others have suggested, the NA does not mean "not
authorized"; rather, it means "not applicable". There is "No DH and no
RVR limitation" for the CAT IIIc approach. Category IIIc conditions has
visibility insufficient for taxi operations according to the text on
page 5-48.

There is no CAT IIIc approach into JFK for runway 4R which is why it is
not listed on the plate.

There is a CAT IIIc approach into Newark; the NA is under the visibility
requirement.

Peter Clark

August 7th 06, 11:35 AM

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?

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?
>>

Bob Moore

August 7th 06, 02:05 PM

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

'Autoland' and 'Approach CAT' are two separate subjects. It is true
that 'autoland' is a requirement for the conduct of an approach and
landing if the wx conditions are below CATII minimums, but autoland
can also be used in VFR conditions.

The reason for the requirement to conduct autolandings every so often
(we had that requirement at the old PanAm) is to insure that the
equipment remains in calibration. If the autolandings were not logged,
the equipment had to be removed from the a/c and bench calibrated at
scheduled intervals.

Many of our PanAm B-727s had autoland capability with only a CATII
approach capability.

Bob Moore
ATP B-707 B-727
PanAm (retired)

Gary Drescher

August 7th 06, 02:13 PM

"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
>. Category I - Decision Height (DH) 200 feet and Runway Visual Range (RVR)
> 2,400 feet (with touchdown zone and centerline lighting, RVR 1800 feet),
>. Category II - DH 100 feet and RVR 1,200 feet,
>. Category IIIa - No DH or DH below 100 feet and RVR not less than 700
>feet,
>. Category IIIb - No DH or DH below 50 feet and RVR less than 700 feet but
> not less than 150 feet, and
>. Category IIIc - No DH and no RVR limitation.
>
>I found the above on page 5-49 of the Instrument Procedures Handbook at
> >http://www.faa.gov/library/manuals/aviation/instrument_procedures_handbook/
>
>So contrary to what others have suggested, the NA does not mean "not
>authorized";
>rather, it means "not applicable".

No, NA means "not authorized". See
http://www.naco.faa.gov/content/naco/online/pdf_files/7th_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.

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

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

> 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

Sam Spade

August 7th 06, 02:26 PM

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.

Sam Spade

August 7th 06, 02:29 PM

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.

Jim Carter[_1_]

August 7th 06, 02:37 PM

> -----Original Message-----

> From: Gary Drescher ]

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

> Posted To: rec.aviation.ifr

> Conversation: CAT IIIC minimums

> Subject: Re: 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/aviation/instrument_procedures_handb
oo

> >k/

> >

....

>

> No, NA means "not authorized". See

>
http://www.naco.faa.gov/content/naco/online/pdf_files/7th_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.

Jim Carter[_1_]

August 7th 06, 02:42 PM

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

Sam Spade

August 7th 06, 02:58 PM

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: Re: 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. ;-)

Jim Carter[_1_]

August 7th 06, 03:36 PM

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

Gary Drescher

August 7th 06, 03:39 PM

"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

Andrey Serbinenko

August 7th 06, 03:59 PM

> 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?
>>>

Sam Spade

August 7th 06, 04:11 PM

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: Re: 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.

Sam Spade

August 7th 06, 04:13 PM

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.

Andrey Serbinenko

August 7th 06, 04:21 PM

> 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.

I have to disagree with you on that: I believe the omission of certain
approach minimums equates to a statement that such approach is not authorized.
On the same plate (KJFK 4R CAT III), there's no circling minimums, and this
doesn't obviously imply that circling with no visibility limitation is allowed.

Andrey

>
>>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
>
>

Andrey Serbinenko

August 7th 06, 04:24 PM

> 'Autoland' and 'Approach CAT' are two separate subjects. It is true
> that 'autoland' is a requirement for the conduct of an approach and
> landing if the wx conditions are below CATII minimums, but autoland
> can also be used in VFR conditions.

OK, I see now. Thanks!

Andrey

>
> The reason for the requirement to conduct autolandings every so often
> (we had that requirement at the old PanAm) is to insure that the
> equipment remains in calibration. If the autolandings were not logged,
> the equipment had to be removed from the a/c and bench calibrated at
> scheduled intervals.
>
> Many of our PanAm B-727s had autoland capability with only a CATII
> approach capability.
>
> Bob Moore
> ATP B-707 B-727
> PanAm (retired)

Gary Drescher

August 7th 06, 05:05 PM

"Andrey Serbinenko" > wrote in message
...
> I have to disagree with you on that: I believe the omission of certain
> approach minimums equates to a statement that such approach is not
> authorized.
> On the same plate (KJFK 4R CAT III), there's no circling minimums, and
> this
> doesn't obviously imply that circling with no visibility limitation is
> allowed.

Sure, but if CAT III approaches inherently preclude circling (which I
suspect is the case), then the omission of visibility minima for CAT III
circling approaches isn't analogous. (I haven't seen an example of a CAT I,
LOC, VOR or NDB approach plate that does not either specify circling minima,
or say explicitly that circling is NA.)

--Gary

Sam Spade

August 7th 06, 06:33 PM

Gary Drescher wrote:
(I haven't seen an example of a CAT I,
> LOC, VOR or NDB approach plate that does not either specify circling minima,
> or say explicitly that circling is NA.)
>

Circling isn't authorized at KLAX and some other major airports, simply
by not having a circle-to-land minima box on the chart. The source
document, however, does state "NA" in the line for circling minimums.

Gary Drescher

August 7th 06, 06:50 PM

"Sam Spade" > wrote in message
news:1QKBg.656$0F5.46@fed1read04...
> Gary Drescher wrote:
>> (I haven't seen an example of a CAT I,
>> LOC, VOR or NDB approach plate that does not either specify circling
>> minima, or say explicitly that circling is NA.)
>>
>
> Circling isn't authorized at KLAX and some other major airports, simply by
> not having a circle-to-land minima box on the chart. The source document,
> however, does state "NA" in the line for circling minimums.

Yup, you're right.

--Gary