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Jimmy Helton

Are CATIII Autolands runway dependent?

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My ability to perform a CATIII autoland is inconsistent even though I seem to be following the same steps every time: (1) enter the ILS frequency from the selected runway in the FMS into both nav radios, (2) set the course on both course nobs, (3) enter runway length and elevation into the HGS,and (4) set autorbakes and arm the speed breaks. I then capture the localizer and hit APR in the MCP.  Finally, I arm both left and right CMD buttons.

 

After following those steps, most of my landings are still single channel.  I should be seeing CMD followed by land3 at 1500 AGL.  The only thing I can think of is that the PMDG FMS somehow knows which runways are CATIII equipped and which are not?

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Sort of. But yes, some airports have the equipment that an aircraft requires for a CAT III landing, but others do not. What airports are you attempting a CAT III landing at?

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Hi,

 

In which mode is the HGS once you have entered the elevation?

 

To get the land 3 indication on the PFD you need both autopilots, three inertial sources and the associated sensors operating normally as per the FCOM v2 (page 4.20.5).

You also need the aircraft to be certified fail-operational autoland.

 

Do you any message on the EICAS (No land 3...)?

 

There is a kind of confusion here. Cat III and autoland are two different things. CATIII is a category of approach (ILS CAT III).

Autoland is a design and capability of the aircraft that allows the FMS to land the plane on itself.

 

You can land manually after CAT III approach and you can technically autoland after other approach than ILS CAT II or CAT III.

When I say "technically", I mean the aircraft is capable of, without considering the pilot decision upon other factors.

 

The FMS doesn't sense the airport equipment to determine whether it can perform an autoland or not. 

 

Whatever the approach is, as long as you don't receive the warning message No autoland, you are technically good to go for the aircraft FMS. Off course, I don't talk about signal reliability or declared LVP... but just from the point of view of the FMS.

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Forgive me if I make a great wrong statement here, but the equipment don't differ from CAT I to CATIIIb, what differs is the protection zones and backup requirements. You can autoland on a CAT I runway, but you aren't assured that nothing will interfere in the same way as during a CAT III, same goes for a CAT III runway as long as Low visibility procedures are not in force.

 

in FSX everything is the same and there shouldn't be any difference other then the limits we put on our self.

 

So the NGX should react the same as long as the runway has an ILS.

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Typically, at least 3 things need to be certified capable before you can conduct Autoland ops - the pilots, the runway and the airplane.

 

So

 

- Make sure you know what to do and what to expect by reading the Intro, FCT and FCO manuals that came with the NGX. Also search YouTube.

 

- Make sure you are tuned to the right ILS frequency and that the runway is CATIII capable.

 

- Make sure the airplane autopilot is Fail - Operational.

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Let me clarify.  I am talking about Autoland, and Kristoffer has clarified that all ILS runways are essentially the same in FSX.  Therefore, it has to be a configuration error on my part.  The HGS goes to ARM III as soon as I dial both nav radios to the same frequency.  Instead of CMD down the glideslope, I get single channel.  Maybe it is a fail operational issue.  I will collect more data and report back.

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I just flew the 31L ILS at KJFK.  I made sure fail operational was set through the operations center and capture glideslope before localizer was set to allow.  To prepare for landing, I dialed the ILS frequency into both nav radios and set it as the active frequency, entered the length and elevation into the HGS which set ARM III, set the course, brakes, and spoilers, and made sure both FD's were turned on.  After intercepting the localizer, I hit approach in the MCP and activated both CMD buttons. As per usual, this changed the green CMD signal to the yellow Single Channel followed by NO AUTOLAND around 1500 AGL.  I can't figure out what I'm missing.

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capture glideslope before localizer was set to allow
It's the other way. Localizer then glideslope. Don't ever capture the glideslope before you have captured the localizer. See page 74 of the Introduction manual.

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Sounds like the second autopilot isn't engaging.

 

-Do it all again with one autopilot.

-Wait until you have VOR/LOC and G/S annunciated on the FMA and you are descending to the runway, then,

-at 2000ft HAT, hit the second autopilot.

-at 1200ft HAT, make sure ROLLOUT and FLARE is armed (below G/S in white writing)

- at 1000ft HAT, make sure VOR/LOC, G/S and LAND 3 are annunciated.

 

Report results here.

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Hi.

 

In reality a runway does not need to be CATII/III equipped to conduct an Autoland in the 738, the aircraft can do it on just a standard CAT I ILS.

 

Again company specific but we're permitted to conduct a PRACTICE CAT II/III to an unprotected runway with visibility 1500m or greater and a cloud base 500ft or higher.

 

As I always stress this is specific to the company I operate for, it might be different with other operators. A practice Autoland is usually conducted because we need to at least to complete one before our 6 monthly sim check.


Forgive me if I make a great wrong statement here, but the equipment don't differ from CAT I to CATIIIb, what differs is the protection zones and backup requirements. You can autoland on a CAT I runway, but you aren't assured that nothing will interfere in the same way as during a CAT III, same goes for a CAT III runway as long as Low visibility procedures are not in force.

 

in FSX everything is the same and there shouldn't be any difference other then the limits we put on our self.

 

So the NGX should react the same as long as the runway has an ILS.

 

Exactly what this chap said!

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Here is short video of how it sort of should be done. I've been far away from the keyboard over the festive season, so I might have frayed a bit, procedurally. But I managed to achieve the desired result... a Fail Operational Autoland. I would have added the link to my comment above, but I am unable to edit it :(

 

https://youtu.be/ElqQU_-lhDw

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I just flew the 31L ILS at KJFK.  I made sure fail operational was set through the operations center and capture glideslope before localizer was set to allow.  To prepare for landing, I dialed the ILS frequency into both nav radios and set it as the active frequency, entered the length and elevation into the HGS which set ARM III, set the course, brakes, and spoilers, and made sure both FD's were turned on.  After intercepting the localizer, I hit approach in the MCP and activated both CMD buttons. As per usual, this changed the green CMD signal to the yellow Single Channel followed by NO AUTOLAND around 1500 AGL.  I can't figure out what I'm missing.

 

I'm willing to bet that there's something you're leaving out in your setup, or you're being inconsistent in how you're setting everything up. It might be worth flying the first tutorial a few times to get into a habit of doing certain things at certain times to give you the best possible shot at getting everything right. If you don't by a certain point, the aircraft will give you the NO AUTOLAND message, realistically.

 

Full names in the forum, please - first and last.

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Hi.

 

In reality a runway does not need to be CATII/III equipped to conduct an Autoland in the 738, the aircraft can do it on just a standard CAT I ILS.

 

Again company specific but we're permitted to conduct a PRACTICE CAT II/III to an unprotected runway with visibility 1500m or greater and a cloud base 500ft or higher.

 

As I always stress this is specific to the company I operate for, it might be different with other operators. A practice Autoland is usually conducted because we need to at least to complete one before our 6 monthly sim check.

 

Exactly what this chap said!

Hi sam great to see you having some input around here. Keep it up!

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Hi all,
 

feel a need to add:
 
- Fail Op autopilot is NOT required for automatic landing (only for rollout)

 

- HGS is NOT required for automatic landing and it DOES NOT matter if it's set up, and how.

 

- Runways in FS world are all perfectly precise ILS wise and will support an autoland as long as there is an actual ILS.

 

- If the option is installed, Glideslope CAN be capured before localizer.

 

- Have both radios definitely set to the same frequency and show the same indications - crosscheck this! Same course ideally as well. And attach second AP soon enough (as soon as you click on APP)

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All true.

 

However

- OP is trying for CAT III, *usually* a fail-op capable aircraft,

- OP is using the HGS (usually buys lower minima for other approach types)

- Second a/p engagement is down to SOP. A company manual might have a 'engage before xxxxft'.

 

I guess the OP has figured out his problem or is working through the manuals? I wonder how he's going...

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However

- OP is trying for CAT III, *usually* a fail-op capable aircraft,

 

Not true, fail-op option is comparatively rare in an NG, and airplanes with fail-passive option are fully capable of (CAT IIIa) automatic landing, only without rollout. To say one has to have fail-op option for autoland to work is therefore in essence a lie, whether intentional or misguided, and damaging to community as a whole in it's understanding of operation. It's the same kind of thing like when people started claiming all of a sudden that using a low CI is a universal remedy for descend problems, while that might only mitigate the symptoms (if even that) of the root problem - improper descent planning.

 

 

 

- OP is using the HGS (usually buys lower minima for other approach types)

 

While true, it is irrelevant, as any HUGS setting does not have any bearing on AFDS behaviour; as such a red herring that should not be discussed while troubleshooting a different system (only adds confusion).

Besides, the lower minima from HUGS only happen for hand-flown approaches anyway, no bearing on automatic landing.

 

- Second a/p engagement is down to SOP. A company manual might have a 'engage before xxxxft'.

 

That is true, but it does have to happen between APP mode engagement and the point where self-check begins -it's therefore important for troubleshooting to ensure that second AP connection is happening consistently before the selfchecks would begin.

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Copper., on 08 Jan 2016 - 06:45 AM, said:

However
- OP is trying for CAT III, *usually* a fail-op capable aircraft,
 
Not true, fail-op option is comparatively rare in an NG, and airplanes with fail-passive option are fully capable of (CAT IIIa) automatic landing, only without rollout. To say one has to have fail-op option for autoland to work is therefore in essence a lie, whether intentional or misguided, and damaging to community as a whole in it's understanding of operation. It's the same kind of thing like when people started claiming all of a sudden that using a low CI is a universal remedy for descend problems, while that might only mitigate the symptoms (if even that) of the root problem - improper descent planning.

 

 

 


After following those steps, most of my landings are still single channel.  I should be seeing CMD followed by land3 at 1500 AGL.  The only thing I can think of is that the PMDG FMS somehow knows which runways are CATIII equipped and which are not?

 

The thing is that the OP was looking for the land 3 indication on the PFD which is - correct me if I'm wrong - only displayed on a fail operational autoland certified aircraft while a fail passive will still be certified for autoland but "only" land 2.

 

I think that there is a large confusion regarding autoland, ILS catII/catIII, fail operational/fail passive, land2/land3... The distinction between the approach type (ILS catII/catIII) and the aircraft autoland capability (land2/land3) seems to be blurry for a lot of people. And especially what can be done with what equipement (whether ground based or on board the aircraft).

 

The question of ILS / autoland is quite recurrent on the forum.

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The thing is that the OP was looking for the land 3 indication on the PFD which is - correct me if I'm wrong - only displayed on a fail operational autoland certified aircraft while a fail passive will still be certified for autoland but "only" land 2.

 

Fair enough, although the green/amber indications, while worded differently, are functionally practically identical.

 

It was, however, stated in this thread:
 

 

 


Typically, at least 3 things need to be certified capable before you can conduct Autoland ops 

 

...

- Make sure the airplane autopilot is Fail - Operational.



which is not true, and that is what I objected to.

 

 

 


I think that there is a large confusion regarding autoland, ILS catII/catIII, fail operational/fail passive, land2/land3... The distinction between the approach type (ILS catII/catIII) and the aircraft autoland capability (land2/land3) seems to be blurry for a lot of people. And especially what can be done with what equipement (whether ground based or on board the aircraft).

 

Agreed.

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Since you're here to nit pick...

 

I don't remember saying fail op is required for autoland. My airline have fail passive but still conduct autoland ops to CAT II minima when required, what I did say was that HGS buys lower minima FOR OTHER APPROACH TYPES... or did you choose to ignore that?!

 

The '3 things' statement was proffered generally, the following three suggestions were case specific.

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I think that there is a large confusion regarding autoland, ILS catII/catIII, fail operational/fail passive, land2/land3... The distinction between the approach type (ILS catII/catIII) and the aircraft autoland capability (land2/land3) seems to be blurry for a lot of people. And especially what can be done with what equipement (whether ground based or on board the aircraft).

 

Unfortunately it is a somewhat complex topic, but at the same time, I'd argue that a lot of the confusion comes from people with sophomoric knowledge (spoken generally here - I haven't paid much attention to what's going on in this thread, specifically) jumping into these discussions and throwing their knowledge out there without any disclaimers. If you look out in real and sim forums alike, you'll see people speaking from supposed positions of knowledge not only telling people "how it is," but debating people who are actually describing it correctly (don't take this to mean that I have never done this - I have, I'll admit that openly). This isn't specific to the ILS thing alone; it covers quite a few topics. At the same time, I think we can all cut out a lot of the misunderstanding by avoiding the use of "ILS landing" and "CATIII Autoland." Both of those put off that the terms are linked. ILS with autoland somewhat implies that an ILS always ends in an autoland (and that autoland is the 'norm'). Even if you know that it does not, you might be surprised at how many don't know this. Additionally autoland could theoretically be used with RNAV - it's just not currently designed to use the cues provided by RNAV, nor is it approved for that yet. The latter "CATIII Autoland" implies that autoland is dependent on CATIII facilities, and it's not. As I always like to point out: the LOC and GS antennas are usually the same for a CATI and CATIII installation. The difference is mainly assurance of signal reception and quality, backup power, and a bunch of pencil whipping.

 

The more people who study up and go read primary sources, the more knowledgeable the community will be, and the less confusion circles around. As a pilot myself, I cringe every time I hear "well my friend is a pilot for XYZ Airlines and he said..." mostly because not everyone is an expert. Think about it. Take any single person and look at their knowledge of their job - any job. Are they perfectly knowledgeable about their job, and how their job interacts with other people's jobs? I'd argue that the average worker has quite a few knowledge gaps about fringe issues (in our realm: the intricacies of an ILS array and how they get certified), specific legalities (interpreting regs), and job roles they interact with (pilots interactions with ATC). I'm not saying people don't know how to do their jobs - I'm simply saying your average person is average. Pilots are people too, and your average person doesn't care enough to know everything. As such, even if you heard it from your best pilot or ATC buddy, it's best to verify before repeating it.

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I don't remember saying fail op is required for autoland. My airline have fail passive but still conduct autoland ops to CAT II minima when required, what I did say was that HGS buys lower minima FOR OTHER APPROACH TYPES... or did you choose to ignore that?!

 

I didn't choose to ignore that - I very specifically said it's irrelevant, since AFDS is totally independent from HUGS and therefore HUGS is in no way related to the problem described; and need not be discussed here.

 

 

 


The '3 things' statement was proffered generally, the following three suggestions were case specific.

 

I appologize if it was your intention to separate the ideas, but it didn't came out that way - to me it seemed like you were saying the airplane needs to have Fail Op to do an automatic landing.

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