CAT lllb with a Decision Height

[Spooky 2]

Looking at some EU OPS1 data and they speak to using a Decision Height with a CAT lllb (fail Operational) approach and I see no mention of a Alert Height in lieu of the DH. What give with that?

Thanks in advance!

[CptRegionalJet]

Goes along with my company`s SOP during LVO.Alert height only mentioned during Cat III/ No DH.:cool:

[gusting_45]

With a DH, the aircraft will give the 100 ABOVE (or whatever your synthetic voice is programmed for) call not 100 as it would without a DH, therefore no Alert Height.

It's a French thing.

[Spooky 2]

Most Alert Heights are set for 50' AGL. How are you working around that lower minimum other than not having either an AH or DH? Obviously you don't need to see the runway with just an AH but I see there is a minimal requirement for visual contact with the DH. :)

[rudderrudderrat]

Hi Spooky2,

If a DH is published then we use "100 above" and "Minimums"
If it's a No DH, then we use "100" at 100 radio (that's the Alert call)- the response is normally "Continue".

[Denti]

Doesn't Alert Height depend on type? We use a flat 200' on our 737s with no DH.

[Mansfield]

There is a particular height used by the manufacturer below which the systems are locked in a fail-operational mode, i.e., busses separated and so forth so that a failure will not result in a downgrade to fail-passive being annunciated. Boeing has traditionally used 200 feet for this purpose.

Then there is the alert height authorized by the authorities, and this is probably where a lot of confusion will settle in. The FAA did approve 50 feet as an AH for a long time; however, my current carrier is only approved to use 100 feet, and when I set up the CAT II/III program at my previous carrier, we were told the FAA was no longer approving a 50 foot AH for a new program (those already in existence being grandfathered, as always).

I can't elaborate on the approved AH under authorities other than the FAA.

[Spooky 2]

Thanks to all that have responded. I just noticed when looking at the Jepp approach plates for either EGLl or EGKK that they do not show any CAT lll approaches? Is that really possible/

[KBPsen]

You will not get any CAT III plates from Jeppesen unless you order them specifically. There is no real need for them anyway.

[Spooky 2]

Mansfield, Boeing still uses 200' for an AH for cetification issue with the caveat that operators can apply for lower AH's and the 50' figure is pretty much standard. Some carriers use Zero and as long as LAND3 is visible on the PFD/ASA/AFDS they continue to the autoland. I'm not aware of any FAA restriction or policy change regarding the 50' AH at this time.

Thanks for your reponse!

[Spooky 2]

KPBsen, Thanks for your reply as well. Jepp publishes CATll/lll approach plates for all airports in the US. They would appear to be missing from the European airports in their JeppView data base. I have call into them at this time and will report back when I have more info. Maybe it's a OPS-1 thing?

Not sure why you would think I would have "no real need for them anyway." What am I missing, as that's sort of what started this string to begin with.:ugh:

[boredcounter]

Just my take as a groundie here.

Jepp seem to publish CATII minima, with Company text (Procedures) listing CATIIA/B minima.

My (EU) lot are changing to 'published' CATIIIA minima on the relevent plate, as and when the plate needs changing.

As such, the plate negates the text list, the plate becoming the published 'Company Minima'.

During the transition, which may take many years, the Aircrew, still refer to the 'Text' for minima, as one would expect, it is their trained and trusted method. Some have questioned the change and it needs some, but not a lot of explaining, to be fair and we, (they) go to CATIIIA minima.

Despite whatever brief for landing by the Crew, 'Published Minima' should be there on the two aproach plates, at least to CATIIIA, if applicable, for both to see, should the call LAND2 come.


Bored the Groundie

[Spooky 2]

Talked to Jepp at their airline desk this afternoon. They only publish CAT lll data for approved operators unlike they do in the US. In other words the Jeppesesn CATlll approach plates are tailored to a specific operators needs and not the geneal flying public.

[Mansfield]

Check this link:

Flight Operations Branch - Category II/III ILS information (http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs410/status_lists/)

You will find two Excel sheets that can be downloaded; one is a list of US CAT II/III runways, the other a list of foreign CAT II/III runways. These are the FAA AFS-400 master lists, and they are updated as necessary.

Jeppesen constructs the tailored charts first by reference to these documents, and then by reference to your company's Op Specs. They publish the most conservative minima between the two sources. Most US runways are still limited to RVR 600, so that is what will appear on your tailored chart even though you have Op Specs approval down to RVR 300. On the other hand, if your Op Specs approval is limited to RVR 600, then even those runways that are approved down to RVR 300 will be published, on your tailored charts, as RVR 600.

If you have a generic, non-tailored CAT III chart from Jeppesen, it will only reflect the AFS-400 minima, and not your company Op Specs.

At least that's the idea.

[aterpster]

Mansfield:

There is a particular height used by the manufacturer below which the systems are locked in a fail-operational mode, i.e., busses separated and so forth so that a failure will not result in a downgrade to fail-passive being annunciated. Boeing has traditionally used 200 feet for this purpose.

That's why I couldn't understand in another thread when someone stated that both autopilots tripped off during the flare of an auto-landing.

Then there is the alert height authorized by the authorities, and this is probably where a lot of confusion will settle in. The FAA did approve 50 feet as an AH for a long time; however, my current carrier is only approved to use 100 feet, and when I set up the CAT II/III program at my previous carrier, we were told the FAA was no longer approving a 50 foot AH for a new program (those already in existence being grandfathered, as always).

Isn't higher better in the case of Alert Height?

[EMIT]

Correct Aterpster, you would want Alert Height to be as high as possible, it is a measure of aircraft capability.

On the other hand, of course, you want Decision Height to be as low as possible.

Reading the posts, it seems a lot of people do not fully grasp the meanings of AH and DH.

If you make an autocoupled ILS approach with a fully serviceable aircraft, on many Boeings that will give an Autoland Status of LAND 3, then your Alert Height is 200 ft. If, below Alert Height, an engine fails, or a generator, or whatever SINGLE FAILURE, then, technically, you can let the aircraft continue it's autoland.
The status of the ILS or weather has not been mentioned yet, in this paragraph. If it is CAVOK and the ILS is only Cat 1, no Low Vis procedures in progress, then you can still let the aircraft do its trick, provided you have had enough visual reference before descent below Decision Altitude. If LowVis procedures are in force, with a DH, you must have ample visual reference before DH, but that decision is a different one than the decision to continue after a single failure below AH.

[Spooky 2]

I can only speak for a few operators, so don't shoot the messenger here. A number of operators do not use an AH at all and instead rely on the ASA or AFDS annunciator (B777) to display LAND3. As long as LAND3 is shown your good for the CAT3B Autoland. Now shoud there be a reversion to LAND2 (Fail Passive), they simply select the preset 50' DH on the RA and press on to a CAT3A (Fail Passive) autoland. This action is part of the briefing and set-up prior to conducting the approach.

Just because your experience is something other than that as described, does not mean it's unsafe, unapproved, or what ever. I think I know something about this subject BTW.

Each operator, depending on equipment, decides on a procedure that is factory approved along with regulatory approvals. They do not simply make this stuff up on their own. The 200' AH is simply a point of reference and is almost always lowered to something below 100' and 50' is most common these days.

[aterpster]

Spooky 2:

Each operator, depending on equipment, decides on a procedure that is factory approved along with regulatory approvals. They do not simply make this stuff up on their own. The 200' AH is simply a point of reference and is almost always lowered to something below 100' and 50' is most common these days.

Which is why neither DA or AH are charted on CAT III approach charts, at least not in the U.S.

[Spooky 2]

That is true and it leads back to the original question. Each operator in the EU apparently has an operator specific tailored chart for these approaches. Makes sense. :ok:

[Escape Path]

Is there a piece of documentation that you suggest to me so I can educate myself a bit further into the whole subject as I'm completely inexperienced at Cat II/III operations :O

Thanks in advance.

Escape Path

[dusk2dawn]

Maybe this tread http://www.pprune.org/french-forum/415712-cat-iii-no-dh-france.html#post5703460 can add something here.
If I remember correctly Google translate came up with something about "no international standard exists" in the french document referred.
There is probably an FAA doc somewhere that Jeppesen can look into for cat II/III in the USA but without such a thingy outside USA Jeppesen will be very carefull about what they put on paper.

[aterpster]

dusktodawn:

There is probably an FAA doc somewhere that Jeppesen can look into for cat II/III in the USA but without such a thingy outside USA Jeppesen will be very carefull about what they put on paper.

IAPs are rule-making amendments in FAA-dom. The rule is quite detailed and issued on a form that all the chart-makers use as the basis for IAP segments andd minimums.

[Spooky 2]

In the US take a look at the following:
AC 120-28A
AC 120-29A
Outside the US:
Pan OPS 8168
ICAO Rules of the Air
Jeppesen ATC 608-614 EU OPS-1 AOM

That should cause your eyes to water over fairly quickly/ :rolleyes: :rolleyes:

[Mansfield]

You'll go mad reading those ACs...although they do form the basis for the actual program at any US carrier. An alternative would be to try these excerpts from the Air Carrier Inspector's Handbook (used to be FAA 8400.10, now 8900.10). They are much better written and actually have a logical flow.

If you go to:

Flight Standards Information System (FSIMS) (http://fsims.faa.gov/)

I'm not smart enough to figure out how to link directly to the content documents, and they don't make that obvious. But a "quick search" window will be in the upper right; do a quick search for the term "CAT III" and you'll get a list of documents. The four listed below should be in the list. They provide a really good comprehensive background on a lot of this stuff...from the US FAA side, that is.


Introduction to and Evolution of All-Weather Terminal Area Operations

General Concepts for All-Weather Terminal Area Operations

Category II Operations

Category III Operations