Sign in to follow this  
Daniel choen

Autoland question

Recommended Posts

Hello, first of all I want to note that I have my PPL, so you can speak "aviation" to me☺.

I have done many ILS, RNAV, VOR DME approaches with piper Seminole, Diamond, C172 etc etc... And still I have this myth in my head remembering someone use to tell me there's ILS approaches without Autoland. So my question basically is, how do I know if the ILS has autoland. I know it depends on the aircraft too, if it able to autoland or not. But are there ILS approaches that aren't autoland? Cheers.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Also depends on the aircraft and what equipment it has on board. 

 

Our 737-800s for example, are unable to land at Leeds Bradford (EGNM) with any tailwind component. 

Share this post


Link to post
Share on other sites

talking proff:
autoland is not related to the category of your ILS , autoland is a capability of your autopilot system to land the a/c on ILS ; whether you see your runway or not.
talking of ILS CAT : categories of ILS approaches are related to the "Reliability of the both Aircraft and Ground Systems" , not precision of them.so both are gonna take you on the same path.

These systems are going to be separated at here :
i.e. you're on a ILS CAT I approach , you're stabilized at minimum. You see the runway , you (Manual or Auto , doesn't matter)
2nd ex : you're on an ILS CAT IIIA approach , at DH you see the runway,you execute autoland , you don't : you execute Auto flight managed go-around

so: you might autoland with both ILS CAT I , II or III but there's a limitation on CAT II that below a certain RVR (usually 350m) you have to use autoland or HUD , only for CAT II ILS APP

Share this post


Link to post
Share on other sites

talking proff:

autoland is not related to the category of your ILS , autoland is a capability of your autopilot system to land the a/c on ILS ; whether you see your runway or not.

talking of ILS CAT : categories of ILS approaches are related to the "Reliability of the both Aircraft and Ground Systems" , not precision of them.so both are gonna take you on the same path.

 

These systems are going to be separated at here :

i.e. you're on a ILS CAT I approach , you're stabilized at minimum. You see the runway , you (Manual or Auto , doesn't matter)

2nd ex : you're on an ILS CAT IIIA approach , at DH you see the runway,you execute autoland , you don't : you execute Auto flight managed go-around

 

so: you might autoland with both ILS CAT I , II or III but there's a limitation on CAT II that below a certain RVR (usually 350m) you have to use autoland or HUD , only for CAT II ILS APP

So every ILS approach can autoland if the aircraft is capable of? Cheers.

Share this post


Link to post
Share on other sites

 

 


Hello, first of all I want to note that I have my PPL, so you can speak "aviation" to me☺.

 

Just as a word of caution, I wouldn't put that out there so readily. Let your knowledge and experience speak for itself. To be honest, a lot of PPC holders (if you're curious as to why I used C instead of L, look at Item III on the card) are very sophomoric in their knowledge. I certainly was. Remember that, even as a private pilot, there's still a ton to learn. Despite having flown the listed approaches, your follow up questions reminded me to mention that there's a vast difference between flying approaches and actually understanding them.

 

 

 


And still I have this myth in my head remembering someone use to tell me there's ILS approaches without Autoland. So my question basically is, how do I know if the ILS has autoland. I know it depends on the aircraft too, if it able to autoland or not. But are there ILS approaches that aren't autoland? Cheers.

 

This one is one of the most incredibly odd simisms to me. I've never quite understood where it came from. In a - probably futile - effort to help dispel this myth, I'll attempt to be very clear:

 

Autoland is rarely used in aircraft operations. It is used when the weather is terrible and it is necessary to conduct a certain type of approach, and it is used to maintain aircraft and crew currency. Heck, some carriers don't pay for the certification and equipment necessary for autoland, and instead use the HGS to sidestep the autoland requirement on certain approaches (which, at the moment, is really only one type, but I'm avoiding naming it because I want to be absolutely clear that autoland and approach type are separate issues - related, but separate).

 

When a controller clears you for an ILS approach, 99% of the time, you are going to take over manually at some point and land the plane yourself. Despite the - forgive the bluntness here - stupid commentary that people use all the time about how automated aircraft are, airlines, and most actual pilots know how valuable stick time is, and strive to maintain that proficiency in the critical segments of flight (takeoff and landing) at the very least.

 

That being said, in theory, you can use an ILS signal to autoland in any aircraft that is capable of autoland. The only difference between a CAT I and a CAT III is certification level: the signal has been verified as accurate, with little interference, and is otherwise fault tolerant to ensure it doesn't quit when you really, really need it. It's the same antenna array, sitting at the end of the runway, with the same glide slope shack sitting next to it. That being said, the inverse is also true. Some CAT I installations, though they have LOC/GS arrays capable of CAT III certification, are only certified to a CAT I because of the amount of signal interference, or terrain issues, and so on. The ILS at CRW is an example of this: normal straight in mins for a CAT I approach are 200 AFE, but they are 500 AFE at CRW because of terrain and related signal quality issues.

 

If we're certifying approaches and changing mins due to signal quality issues, do you really want your aircraft using that signal to autoland? Probably not. For that reason, autolands are generally restricted to CAT III installations (by airline OPSPEC, which is essentially "FAR" if approved by the FAA - note that the FARs do not reference autoland next to any particular approach), due to their being certified at the highest standard. At the same time, if I were flying into IAD, I do not need to be cleared for the CAT III approach over the standard (CAT I) ILS approach in order to use autoland - the array is the same, the signal is the same, the equipment on the plane is the same. You would not want to autoland on a visual approach day, though, as the controllers will not be protecting the signal areas by instructing aircraft to hold short of the ILS Critical Area. Without this, the signal could be compromised. As such, on a visual day, request it from the controller, and they will coordinate it with the tower.

 

Check the Charts. ILS Cat 3a, b, and c has autoland

 

Not quite. See above. Please do what you can to help avoiding the spread of this misconception.

Share this post


Link to post
Share on other sites

Not quite. See above. Please do what you can to help avoiding the spread of this misconception.

 

So, CAT3 a, b, and c do not allow autoland?

Share this post


Link to post
Share on other sites

 

 


So, CAT3 a, b, and c do not allow autoland?

 

You'd better read again what Kyle explains on his post above.

ILS Cat III are certified for autoland but may or may not be used for autoland depending on the situation.

Not only the equipment must be certified but also the ATC must clear you for autoland as other factors are to be considered like the protection of the signal with cat II or cat III holding point for runway (to avoid interferences with aircraft standing on ground close to the antennas).

If you look at airports equipped with cat II or cat III ILS they have different holding points for runways the cat I being the closest to the runway and cat II and cat III being the farest.

Share this post


Link to post
Share on other sites

talking of ILS CAT : categories of ILS approaches are related to the "Reliability of the both Aircraft and Ground Systems" , not precision of them.so both are gonna take you on the same path.

 

 

As a side note, in the case of CATIII, it's also related to a specific crew certification, in addition to the points mentionned above.

Share this post


Link to post
Share on other sites

The questions asked about ILS and autoland. I stated that CAT3 a, b, and c have autoland function. There are obviouslly other parts to it, i,.e the plane must support it, but my answer is true. Kyile stated what I said wasn't true, so I'm asking; is it true that CAT3 a, b, c do not have autoland function.

 

If CAT3 a, b, and c do have autoland function, as I stated, then Kyle please do you part and not spread misinformation as you have done

Share this post


Link to post
Share on other sites

So every ILS approach can autoland if the aircraft is capable of? Cheers.

In FSX every ILS will support an autoland as long as the equipment options for the aircraft are set correctly.

Share this post


Link to post
Share on other sites

Hi Chris,

 

 

 


The questions asked about ILS and autoland. I stated that CAT3 a, b, and c have autoland function. There are obviouslly other parts to it, i,.e the plane must support it, but my answer is true. Kyile stated what I said wasn't true, so I'm asking; is it true that CAT3 a, b, c do not have autoland function.

 

The point Kyle is making is that autoland is not a function of the ILS installation. So it is not correct to say that "A CATIII ILS has autoland".

 

The aircraft has autoland functionality. But when you tune and capture an ILS, the aircraft doesn't know whether it's a CATI, CATII or CATIII beam. It will just do its thing, and it is quite possible for the aircraft to successfully autoland on a CATI installation.

 

As described above, the differences in terms of the ground installation between a CATI and a CATIII certified ILS are largely around redundancy -- in terms of electrical backup if there's a power cut, for instance. Also the beam will be checked to ensure it provides satisifactory guidance all the way through touchdown and rollout, there are no odd terrain effects that would cause beam distortion in the late stages of the approach, and appropriate safeguarding procedures will be put in place to ensure that the ILS critical areas are not infringed during low visibility ops. There are also minimum runway and approach lighting requirements for CATIII operations, which are tied in to the certification process as well.

 

But, as I say, the aircraft just sees an ILS signal and does what it does, including performing an autoland if the pilot configures the automatics appropriately, regardless of what category the beam is certified to.

 

You are, however, more likely to experience undesirable results on a CATI-only runway, purely because the ground installation hasn't been certified to the same level. Hence, as Kyle alludes, most airlines will only approve autolands -- whatever the reason for the autoland -- on runways appropriately certified (i.e. CATII/III).

Share this post


Link to post
Share on other sites

Gents,

 

Please, please, please take a moment to step back and analyze how much you know here. If you're simply going off of what you've found on a sim site, or what another simmer has told you, please take a moment to re-read my earlier post, and the content below as well. Heck, even some real world sites don't get this specific enough for the average simmer learn properly enough to re-tell it to other simmers (or, to be fair - pilots to other pilots, even).

 

While a lot of you are getting the core concept mostly correct, some aspects are incorrect, and this is only going to cause issues for all of us later when we're trying to re-teach everyone with the proper information. In many cases, those discussions become very impassioned as people don't like being told they're wrong. And they're wrong because people are perpetuating falsehoods without thinking - knowingly or unknowingly. This is a lot more complex than a lot of people give it credit for, and the flareups that result from people having to correct past misunderstandings is completely avoidable.

 


If CAT3 a, b, and c do have autoland function, as I stated, then Kyle please do you part and not spread misinformation as you have done

 

Well, that's certainly a very bold statement there...particularly when someone who works in developing FAA Procedures is providing a very detailed answer, and noted your original text was incorrect.

 

 

 

Firstly, CAT IIIa/b/c doesn't have an autoland function. In fact, ILS approaches (regardless of CAT) have no "functions" at all apart from the provisions of a horizontal and vertical path for an aircraft to follow. The CATs simply denote signal strength, clarity and reliability, to a particular certification standard (a CAT III certified array that fails 5 times in a 6 month period gets automatically kicked down to a CAT II array, as an example - all the same equipment though). How an aircraft interprets and acts upon that info (again, regardless of CAT) is a completely separate topic.

 

To fly a CAT III a/b/c approach requires autoland (AC120-28D), but this is a regulatory requirement alone. This is evident in the fact that if a HGS is installed and approved by the administration, CAT III approaches may be flown manually.

 

The inverse - autoland requires CAT III - is not true. Therein lies the simism, and that is what I was addressing:

  1. ILS approaches, by and large, are not completed in autolands.
  2. Autolands can be conducted on any ILS CAT, in theory
    The equipment is all the same - approval may vary. If the OpSpecs approved by the administration only refers to autolands on CAT III arrays, then autolands can only be conducted on the runway with a CAT III certified array at a particular facility.

It is, however, approved if you've included it in your OpSpecs:

FSIMS 8900.1 4-342:

CAT I Autoland or HUD to Touchdown Operations. Autoland or HUD to touchdown operations are required for all CAT III operations, and many operators use autoland or HUD for CAT II, CAT I, and visual flight rules (VFR) operations as well. Part 121, § 121.579©; part 125, § 125.329(d); and part 135, § 135.93(d) prohibit the use of autoland or HUD to touchdown in any operation unless the operator is specifically authorized via OpSpecs. OpSpec C059 and C060 authorize autoland or HUD to touchdown in CAT II and CAT III operations, respectively. OpSpec C061 or H110 authorizes autoland operations in other than CAT II/III operations and OpSpec C062 or H111 authorizes HUD to touchdown in other than CAT II/III operations.

 


but also the ATC must clear you for autoland

 

This isn't true, unless it's specified in the OpSpec. You would want to be careful of autolanding in visual conditions as the controllers are not protecting the ILS critical areas, which means signal interference could be an issue. That close to the ground, you wouldn't want that. They would be protecting this area when conducting ILS approaches (at any CAT), so if they only cleared you for the run-of-the-mill ILS approach, you can still autoland (in theory, it's capable; legality is in question if it's a non CAT III array, depending on your OpSpec - see above reference to FSIMS) if you so choose, without getting a specific clearance. To be even more clear, "autoland" is only mentioned in the controller handbook to advise the controller to issue a warning to the crew if a crewmember advises (note: not "requests clearance for") that they will be conducting an autoland when weather is above the LVP cutoff:

 

7110.65V 3-7-5 b 2:

b. Operators commonly conduct “coupled” or “autoland” approaches to satisfy maintenance, training, or reliability program requirements. Promptly issue an advisory if the critical area will not be protected when an arriving aircraft advises that a “coupled,” “CATIII,” “autoland,” or similar type approach will be conducted and the weather indicates a reported ceiling of 800 feet or more, or the visibility is 2 miles or more.
PHRASEOLOGY−
ILS CRITICAL AREA NOT PROTECTED.
 
Note that, while the 7110 refers to "CATIII" in the above text, this is simply because of the connection between the CAT III approach and the requirement for autoland when flying those approaches (if they had a HGS exemption, they wouldn't need to be be testing the autoland, which means they wouldn't be advising ATC of anything).

 


The point Kyle is making is that autoland is not a function of the ILS installation. So it is not correct to say that "A CATIII ILS has autoland".

 

Precisely.

Share this post


Link to post
Share on other sites

Sorry for my mistake.

I would like to take the opportunity to ask a question that maybe will reveal that I didn't understand nothing...  :wink:

 

When setting the mins for ILS approach, I usually pickup cat I mins when the weather allows it.

If reaching the MDA I don't have a visual on the runway, I would do a go-around:

 

Now here is the (multiple) question.

On the NG, to set up for a cat I, afaik, you may set the ILS frequency on only one nav and course only on the corresponding side of the MCP.

Now if I find weather to be below the cat I mins, do I need a special clearance to fly a cat II or III approach with ILS set on both receivers or do I need to advise the controller for the second approach?

 

For the T7, the setup is the same whatever the cat is except for the mins. But when picking up a mins MDA or DH should I automatically set the lower mins available or cat I and go-around if below mins?

 

Hope my question is clear.

Thanks.

Share this post


Link to post
Share on other sites

 

 


Now if I find weather to be below the cat I mins, do I need a special clearance to fly a cat II or III approach with ILS set on both receivers or do I need to advise the controller for the second approach?

 

I'd be interested to hear from those with better legal grounding than I on this topic, but this is what I would do.

 

Essentially, the question moves from being a technical issue to a legal and operational issue.

 

If you have briefed a CATI approach with a DH of xxx, then if you get to DH and can't see anything you must go around.

 

What you do next then becomes a question of what your airline requires for a CATII or CATIII approach.

 

Most that I am aware of would require the airfield to be in LVPs before conducting an actual CATII or CATIII approach. Certainly, the ILS must be safeguarded and the appropriate power switching done on the ground (backup generators fired up etc). So it would be sensible to advise the controller that your at CATII/III capable -- however, you will need to wait until the airfield has implemented all the appropriate safeguarding procedures before you can actually perform the approach.

 

Likewise on the T7 -- if the airfield is not in LVPs, there is no guarantee that the ILS backup generators are running, the ILS critical areas are protected etc etc, so you should only bug the CATI DH.

 

Once you have the appropriate safeguarding in place you can then perform a CATII or CATIII approach -- as far as I know most airfields once in LVPs will safeguard to CATIII standards (if available) so assuming you and the aircraft are qualified you would probably set up for a full CATIII rather than faff around with a CATII DH, possibly not get in and have to come back for a CATIII.

Share this post


Link to post
Share on other sites

 

 


This isn't true, unless it's specified in the OpSpec. You would want to be careful of autolanding in visual conditions as the controllers are not protecting the ILS critical areas, which means signal interference could be an issue. That close to the ground, you wouldn't want that.

It may not be required but surely you ought to declare you intend to make a practice autoland so that ATC can ensure the CAT II/III holding points are used.

Share this post


Link to post
Share on other sites

Most that I am aware of would require the airfield to be in LVPs before conducting an actual CATII or CATIII approach

 

So listening to ATIS "LVP in progress" would be the trigger to select a DH and setup for ILS cat II or cat III.

If not then remain with MDA and setup for ILS cat I?

 

I guess that the airport would then switch to LVP as soon as below cat I minimum?

Share this post


Link to post
Share on other sites

 

 


From the passengers' perspective, every landing is an autoland.

 

Never a truer word spoken.

Share this post


Link to post
Share on other sites

 

 


The CATs simply denote signal strength, clarity and reliability, to a particular certification standard

 

This caught my eye. I agree that reliability and performance are key factors in the category certification but was not aware that signal strength or clarity (which is a function of signal/noise ratio and hence signal strength) was a factor. I am familiar with flight checks from my career in the AF in ground communications-electronics (all the ground electronics at the airfield), but do not recall different flight checks for different categories. That is probably just my lack of direct knowledge, since I was ususally more concerned about gophers eating the coax from the PAR to the RAPCON LOL.

Share this post


Link to post
Share on other sites

At Heathrow the airport rules are:

Cat II and Cat III can be used subject serviceability of the required facilities by operators whose minima are accepted by the CAA and by serviceability of the required facilities.

Special ATC Low Visibility Procedure will be applied to Cat II and Cat III operations  Pilots will be infoemed when these are in operation by Arrival and Departure ATS or by RTF.
 

Also, at Heathrow training flights are not permitted. At other airports it will will subject to prior permission. ATC will not disrupt operations to ensure the CAT II/III holding points are used.

Share this post


Link to post
Share on other sites

 

 


On the NG, to set up for a cat I, afaik, you may set the ILS frequency on only one nav and course only on the corresponding side of the MCP.
Now if I find weather to be below the cat I mins, do I need a special clearance to fly a cat II or III approach with ILS set on both receivers or do I need to advise the controller for the second approach?

 

This one is best discussed by mentioning the concept of restriction. In aviation, the general rule of thumb is:

  • If you are given less restriction, you can operate at your discretion at a higher level of restriction; but
  • If you are given more restriction, you cannot operate at a lower level of restriction.

In other words, the weather permits visual operations, you can dial in and use the ILS signal as a guide, and many operators suggest or require this of their crews. You cannot, on the other hand, get cleared on a CAT III approach, and fly it using with only visual references.

 

More specific to your question, ATC will assign and clear people onto the appropriate ILS approach for the weather. Which CAT you can fly is related to your capability (as a crew, and as an airframe), and you would have to advise ATC if you were incapable if they told you to expect an approach that you couldn't fly. ATC doesn't have a master list of who can fly what (though they do have a general idea from working experience - plus, different aircraft in the fleet may not be capable), so they say "expect [X] approach," and it's up to you to advise if unable. The note of LVP in the ATIS (as Simon mentioned), notes that CAT II and III approaches are in use, and would be a good time to consider your options and prompt ATC if you were incapable.

 

 

 


For the T7, the setup is the same whatever the cat is except for the mins. But when picking up a mins MDA or DH should I automatically set the lower mins available or cat I and go-around if below mins?

 

Mins only matter if you can't see the ground. As soon as you see the runway environment, the concept of mins is moot. Regardless, set the mins for the approach that you've been told to expect and are cleared on. If it's a non-LVP day, then just set the standard ILS mins. If it's visual, then you don't need to set anything, even if you're using the ILS signals as a guide.

 

 

So listening to ATIS "LVP in progress" would be the trigger to select a DH and setup for ILS cat II or cat III.

If not then remain with MDA and setup for ILS cat I?

 

I guess that the airport would then switch to LVP as soon as below cat I minimum?

 

LVO is a little more specific than the mins alone. LVO/SMGCS plans are set up per airport, and each one has its own weather trigger. Just listen to the ATIS to determine if it's in those ops or not. Either way, you use the mins for the approach you've been told to expect (and modify it to the one you're cleared on, if necessary - rare, but can happen) once you check in with the approach controller.

 

 

 

Again, I must stress that weather days like this, in most of the world, are extremely rare. An ILS is going to be a standard (CAT I) ILS the majority of the time. It's the exceptional days where you fly CAT II and CAT III, and in those cases, flights usually end up getting delayed/cancelled until the weather moves on. The CAT II/III approach is used more as a "we're already in the air, the weather came in earlier than we'd planned, and we'd prefer to not divert somewhere else" kind of thing in most places. Additionally, approval for these types of operations doesn't come cheap (remember, SWA, and other operators use the HGS in an effort to sidestep the autoland requirement of CAT III, and the HGS is not cheap), so coming across the operation is even rarer, as there are fewer operators who are approved for it.

Share this post


Link to post
Share on other sites

Hi,

 

Thanks for the great explanations. I think my "problem" comes from the fact that I'm only faced to that kind of situation in a sim environment (IVAO) where most of the time you are provided with partial information (no ATIS when no ATC and sometimes fancy ATIS with human ATC...).

 

It happened to me several times to be well below cat I minimum and not to see any reference to LVP because the controller didn't specify it in the ATIS. In this case, I always wonder whether I should notify the ATC that I'm gonna fly ILS cat II or cat III.

Of course it doesn't really matter as the ILS signal is always perfect in fsx and never subject to interferences (which could be a great improvement in a future sim by the way).

But it is just in an attempt to get the most realistic immersion.

Sometimes I set up initially for a cat I and change to cat II or III while descending on the glide to avoid a go-around if I'm tight on the schedule. Sometimes I just go around and set up for a new approach...

 

I guess the change in configuration should not be done so late in the approach.

 

But most of all, I must be overthinking all this a bit because it's nothing more than a flight sim.

 

Flying VFR only in real life keeps me well away from these considerations!

What? My DR-400 is not certified cat III??? how possible is that!!! Ok, it is not even IFR certified...  :Devil:

Share this post


Link to post
Share on other sites

 

 


Never a truer word spoken.

 

Maybe not for long; I can only imagine some new a la carte options from Spirit, Frontier or Ryanair.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this