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taneb

ILS CAT QUESTIONS

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So I know what the difference is between the categories, but there’s some stuff I’m in the dark about.

1. Does ATC have to clear you for a CAT I or II approach, or is that solely a decision the pilots must make based on their capabilities?

2. If the weather conditions call for a CAT II, could the pilots just go ahead and execute a CAT III approach just in case the clouds are lower than reported?


Tanin Shipman

 

I may be young, but one of these days I'll be flying you around...

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That would be a pilot based decision, but the runway also has to be capable for such an approach. You're not going to execute a CAT III approach onto a runway that isn't CAT III capable. In addition, you'd have to let ATC know what you were doing, so they can keep the ILS critical areas clear.


Captain Kevin

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Air Kevin 124 heavy, wind calm, runway 4 left, cleared for take-off.

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Kevin

For Cat II and III you need to be qualified and trained for, ATC will keep the ILS critical areas clear when the ceiling is at or below 800 FT and or visibility is 2 miles or less.

As to let ATC know what you do is a requirement where you should advise the tower that you conducting and autoland or coupled approach to ensure that the ILS critical area is protected when you inside the ILS MM. 

 


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Agree with all the above but under EASA, LVPs (Low Visibility Procedures - involves many things, one of which is keeping the ILS critical areas clear) are only required when the RVR (Runway Visual Range) is below 550m for an approach and 400m for a take off.

If we used ceiling less than 800ft and 2 miles vis in London we'd be almost permanently in LVPs 😢

1) What category of approach to fly is the pilots decision but it's heavily based on what ATC/the weather man has told them and also the state of the aircraft and intended runway and the current level of all their training.

2) Yes, in the company I fly for, if it's worse than CAT I, then we autoland to the lowest minima we can.

Apologies for the pedantry, you've caught me mid sim revision....

HTH

Ian

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2 hours ago, iwebber said:

 

If we used ceiling less than 800ft and 2 miles vis in London we'd be almost permanently in LVPs 😢

 

Ian

Ian,

Please do not confuse low visibility procedures with automatic landing AUTOLAND ATC regulatory requirements.

LVP means procedures applied at an aerodrome for the purpose of ensuring safe operations during lower than standard category I, other than standard category II, category II and III approaches and low visibility take-offs.

Low Visibility Procedures (LVP) are usually defined as a set of procedures established at an aerodrome in support of CAT II/III approaches and landings.


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7 minutes ago, killthespam said:

Please do not confuse low visibility procedures with automatic landing AUTOLAND ATC regulatory requirements.

What are “automatic landing AUTOLAND ATC regulatory requirements”?

Whatever they are, at 2 miles vis and 800ft cloudbase, they’d better not be too restrictive, we’d still be in them most of the year.

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Sorry,

You need to brush up on ATC procedures and under ICAO/EASA/FAA etc to understand when LVP is enforced and ILS critical area markings.


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14 hours ago, killthespam said:

Kevin

For Cat II and III you need to be qualified and trained for

Yes, I'm aware of that. The original question was:

20 hours ago, taneb said:

Does ATC have to clear you for a CAT I or II approach, or is that solely a decision the pilots must make based on their capabilities?

I guess I tried to simplify it, but as the original question would imply, if the aircraft and/or crew aren't capable of doing a CAT II or III approach, you wouldn't be doing it at all. Assuming they are, it would be a decision for the pilots to make, not ATC, assuming the runway is also capable of such an approach.


Captain Kevin

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Air Kevin 124 heavy, wind calm, runway 4 left, cleared for take-off.

Live streams of my flights here.

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8 hours ago, killthespam said:

Sorry,

You need to brush up on ATC procedures and under ICAO/EASA/FAA etc to understand when LVP is enforced and ILS critical area markings.

Are you a real pilot who uses LVP's?


David Porrett

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Yes David, I am.


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8 hours ago, killthespam said:

Sorry,

You need to brush up on ATC procedures and under ICAO/EASA/FAA etc to understand when LVP is enforced and ILS critical area markings.

I've already told you when LVP's are required in EASA, it's in my first post, I'm only a pilot so I'm happy to accept I'm not given the whole picture and certainly not as familiar with the ATC procedures, hence I asked.

This whole thread was about sharing our knowledge of low vis ops, to merely inform me I don't know isn't really in the spirit of forums, Avsim or the whole internet really.

I'll try again...

What are “automatic landing AUTOLAND ATC regulatory requirements”?

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I'm sorry I didn't mean to offend anybody.

When I mentioned about brushing it was not intended to cause any inconvenience, I'm the first one to admit that I learn every day and that I don't know it all.

Having said that, I fly internationally (all over the world) and I'm supposed to know the law and ATC procedures for each country we fly into. I know, wishful thinking, that's where we brush our knowledge before each flight during our briefings (AIP, AIM, etc) and remind ourselves how little we know or how easy we forget things.

When I was mentioning about 800 & 2 ATC has to keep clear the ILS critical area (some will do autoland), next is when it really goes down to CAT II x III and LVP get inforced and autolands kick in. That's part of regs and ATC requirements.

I just remembered one of the notorious places (DXB) where they love to bust pilots for not stopping short of the ILS critical area when visibility is as such. 


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24 minutes ago, killthespam said:

When I was mentioning about 800 & 2 ATC has to keep clear the ILS critical area (some will do autoland), next is when it really goes down to CAT II x III and LVP get inforced and autolands kick in. That's part of regs and ATC requirements. 

Not sure this is universal; I don't doubt it is the case at DXB but certainly at Heathrow, as Ian suggests, if you are expecting the ILS to be protected in those conditions you will be disappointed!

As Ian says, at least at LHR they only look at the RVR; it could be OVC002 but if the RVR is above 550m they still won't be protecting the ILS or in LVPs unless they are getting reports that aircraft are not getting the visual references.

(Source: direct from the man in the tower!)

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7 hours ago, killthespam said:

...next is when it really goes down to CAT II x III and LVP get inforced and autolands kick in. That's part of regs and ATC requirements.

Lots of (at least) questionable/incomplete stuff you are posting. FYI, CAT II/III and autoland aren't in any way connected since you can (or even have to) e.g. fly manual CAT III approaches.

@Simon, by far the most professional and calm guys I ever worked with are the guys in the LHR tower (and approach of course as well). Always a great pleasure to fly into LHR!

Edited by FDEdev

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This is just from the memory, ICAO Annex10, UK CAA has a requirement that the Sensitive Area must be cleared of any moving obstacle (taxiing, holding aircraft) as soon as the approaching aircraft is closer to 2 NM from Threshold.

Now, what is happening at LHR and what the regulations say that's a different story.

I know for sure that at CDG they have it reduced to 1 NM with an info note to the flight crews about a late landing clearance.

FDEdev, regarding CAT II and III there are reference tables with required indications and equipment for this type of operations.

Autopilot (s), Autobrakes,  Automatic Altitude Callouts,  Autothrottle,  Radio Altimeters,  Windshield Wipers just a few to name.

Also, FYI training and recurrency at the airlines are conducted and checked with A/P on for CAT II x III being part of the requirements.


I9- 13900K- CPU @ 5.0GHz, 64 GB RAM @ 6200MHz, NVIDIA RTX 4090

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