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Driver170

Rvr/vis and ils cat1

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What part of "Decision Height" don't you get? If you can't see the runway at DH you can't land, ILS or not.

 

No one need bother to answer your questions in future, since you claim to be raising them so others can learn.

 

While we're being meticulous.... CAT1 is actually flown on Decision Altitude, not on Decision Height (barometric altitude) :P . And you don't need to see the actual runway. If you have visual reference with elements of the approach light system, you may proceed below DA.

 

At airports with a good approach light system, you can easily proceed despite a reported vertical visibility of only 100 feet because the lights pierce right through the fog/low clouds.

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While we're being meticulous.... CAT1 is actually flown on Decision Altitude, not on Decision Height (barometric altitude) :P . And you don't need to see the actual runway. If you have visual reference with elements of the approach light system, you may proceed below DA.

 

At airports with a good approach light system, you can easily proceed despite a reported vertical visibility of only 100 feet because the lights pierce right through the fog/low clouds.

Yes, when I said runway I did intend that to include the associated lighting. But if you are in cloud you may not see that. I know it's unlikely but it is a possibility.

 

I did mention it earlier, but thanks for repeating the distinction between DA for CAT I and DH for CAT II and III.


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What part of "Decision Height" don't you get? If you can't see the runway at DH you can't land, ILS or not.

 

No one need bother to answer your questions in future, since you claim to be raising them so others can learn.

 

 

Do you think i post up questions for the fun of it? like many others who find all this confusing i'm just raising answers that i have gone and found out and then delivering it on this to make sense of things. i was only bringing more good info to the table kevin. 

 

as i have found out you can have a cloud base lower than DA 200 cat 1 and still and continue


Vernon Howells

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As long as you have sufficient visual reference at DA, you can land. If the DA is 200ft and cloud base is 200ft, it is fairly unlikely that you'll get sufficient visual reference.

 

Edited for clarity.

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Do you think i post up questions for the fun of it? like many others who find all this confusing i'm just raising answers that i have gone and found out and then delivering it on this to make sense of things. i was only bringing more good info to the table kevin.

 

Well it seemed so, when I answered your question about CAT I, II and III minima and you responded with a cut and paste from an online document to try and prove me wrong. If I had been wrong I wouldn't mind but you misunderstood what you quoted.

 

as i have found out you can have a cloud base lower than DA 200 cat 1 and still and continue

What you found says no such thing. It says if you have the required visual refence you can continue below DA/DH. You said that meant if you were on the ILS you could continue. What it means is you can see the approach lights and possibly the runway. If cloud base is below 200' it's quite ikely you won't see the visual references.

 

How can you go from not knowing about something to being an expert on it in one post? Think before you make posts like that. A bit of gratitude for the answers given by people wouldn't go amiss either.

Of course you can - as long as you have sufficient visual reference at DA, you can land.

If you are in cloud how will you have sufficient visual reference?


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Not saying i'm a expert. I did say above this is what i have FOUND so i posted it up but like you mentioned you have to have visual reference at DA. But i also read alot of times at DA with cloud base mostly stratiform cloud you will see the HIAL shinning through. Also alot of youtube videos i've seen tonight shows this.

 

 

I only wanted to find out what causes a pilot to go from Cat 1 normal ILS app to CAT 3 app but as i have found out this also down to LVO at an airport


Vernon Howells

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Quite honestly, a lot of the posts just end up dragging more confusion into the mix than answers.

 

The fact that you were arguing against Kevin's assertion that ceiling is part of the minimums (it is - that's a fact) only serves to add confusion to anyone trying to get a grasp of this. All I see from your posts is your digging for information and the re-posting it here without either fully understanding it, or fully researching it. The way you post this information is very matter of fact (and often pasted directly from PPRuNe). This might lead people to believe that what you are posting is actually true, when in reality, only part of it is in many cases, or you're confusing the intricacies of the information.

 

While I'm sure you see this as "bringing good info to the table," the very fact that there are more than a few very knowledgeable people in here with many years in the aviation industry challenging this "good info" means that it's either not correct, or not being conveyed properly. This only serves to confuse people.

 

I've been guilty of doing similar things in the past - more specifically talking about issues I didn't know as much as I should've - but we do not need people running off to various other forums and then regurgitating information they don't truly understand over here. It's irresponsible, honestly, as it could lead people astray. We're here to guide people, and the last thing we need in the aviation industry is to have to undo more misunderstandings.


Kyle Rodgers

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I don't see any rules getting broke here, i only quoted 1 document from JAR OPS

 

WOW big crime the rest i wrote and whats so misunderstanding here?

 

I'm only trying to say what i found and that is you don't need cloud base or ceiling for a precision approach kyle, the reason is with good HIAL and at 100ft you'll see the lights through the stratiform clouds.

 

How can sources from JAR OPS be misunderstanding.


Vernon Howells

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Hello Vernon,

 

the JAR OPS what you just postet is the commencement and continuation of any type of approach. Lastly the decision rest with the commander in regards to this rules.

 

BTW if you shoot a CAT I approach then you have to dial in the MDA (Minimum Descent Altitude at least it is an SOP in my company and it is also stated on the approach plates) In case of an CAT II/III Appr a decision height will be dialed in.

 

concerning the question "how a pilot know when to fly a CAT I,II,III ABC approach" This will be stated in the current ATIS of a given airport. For ex Munich Int EDDM is a well known airport for LVO as it was built into a swamp  :unsure: The whole world can have CAVOK but EDDM reports RVR all parts 250m on both RWYs. 

 

So the ATIS is the first source of information about the LVO status. A CAT I procedure is rarely reported only LVO will be explicit reported.

 

Besides all that in a multi crew environment both pilots have to be LVO rated. In my case down to a DH of 50´(CAT IIIA) as well as the FO has to be CAT IIIA rated otherwise the flight will be limited to CAT I only.

 

Another general info, for a precision approach only a RVR is required. Ceiling and visibility is only required for non precision approaches.

 

CAT I approaches can be flown manually or with the autopilot, CAT II/IIIA approaches have to be autoland or flown manually with an single/dual HUGS equipped airplane.  


Greetz


MJ


 


My youtube blog________________________Prepar3D v2.5/v3


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The fact that you were arguing against Kevin's assertion that ceiling is part of the minimums (it is - that's a fact) only serves to add confusion to anyone trying to get a grasp of this.

Again, if you want to be meticulous about posting correct info here, it is not a fact. The only minima are RVR (or converted VIS) and DA. The fact that you might not get visual reference at your DA because cloudbase/ceiling is below 200ft does not make the cloudbase/ceiling a minima. It will be a cause for not getting visual reference at DA, but that again does not make it a minima. I've yet to come across the JAR/EU-OPS/EASA regulation that specifies you must have a cloudbase of 200ft to shoot an approach, perhaps there is an FAA one...

 

It is a minima for planning alternates and that kind of stuff, but it is NOT a minima for a CAT1 ILS approach.

 

So, recap for anyone reading this thread later:

 

CAT1 ILS approach minima in layman's terms:

  • 550m RVR TDZ or higher as specified on the approach chart.
  • Lowest DA of 200ft AAL (note, decision altitude, not height, so flown on barometric pressure, not radar altimeter).
  • Visual reference to the approach lights or runway required at DA. A faint glow in the clouds does not constitute visual reference.
  • Cloudbase or ceiling may be reported below 200ft AAL (eg. VV001 or OVC001), it does not stop you from making the approach as long as you have visual reference at DA.
  • When to switch to CAT2 or CAT3? When RVR drops or is below 550m or when you couldn't get visual reference at CAT1 minima. If cloudbase is reported to be below 200ft and you are CAT2/3 able, it might be wise to go for one of those from the start.
I believe that's it all neatly summarized?

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Again, if you want to be meticulous about posting correct info here, it is not a fact. The only minima are RVR (or converted VIS) and DA. The fact that you might not get visual reference at your DA because cloudbase/ceiling is below 200ft does not make the cloudbase/ceiling a minima. It will be a cause for not getting visual reference at DA, but that again does not make it a minima. I've yet to come across the JAR/EU-OPS/EASA regulation that specifies you must have a cloudbase of 200ft to shoot an approach, perhaps there is an FAA one...It is a minima for planning alternates and that kind of stuff, but it is NOT a minima for a CAT1 ILS approach.So, recap for anyone reading this thread later:CAT1 ILS approach minima in layman's terms:

  • 550m RVR TDZ or higher as specified on the approach chart.
  • Lowest DA of 200ft AAL (note, decision altitude, not height, so flown on barometric pressure, not radar altimeter).
  • Visual reference to the approach lights or runway required at DA. A faint glow in the clouds does not constitute visual reference.
  • Cloudbase or ceiling may be reported below 200ft AAL (eg. VV001 or OVC001), it does not stop you from making the approach as long as you have visual reference at DA.
  • When to switch to CAT2 or CAT3? When RVR drops or is below 550m or when you couldn't get visual reference at CAT1 minima. If cloudbase is reported to be below 200ft and you are CAT2/3 able, it might be wise to go for one of those from the start.
I believe that's it all neatly summarized?

You speak the final chapter! Thanks that clears everything up.

 

Hello Vernon,

 

the JAR OPS what you just postet is the commencement and continuation of any type of approach. Lastly the decision rest with the commander in regards to this rules.

 

BTW if you shoot a CAT I approach then you have to dial in the MDA (Minimum Descent Altitude at least it is an SOP in my company and it is also stated on the approach plates) In case of an CAT II/III Appr a decision height will be dialed in.

 

concerning the question "how a pilot know when to fly a CAT I,II,III ABC approach" This will be stated in the current ATIS of a given airport. For ex Munich Int EDDM is a well known airport for LVO as it was built into a swamp  :unsure: The whole world can have CAVOK but EDDM reports RVR all parts 250m on both RWYs. 

 

So the ATIS is the first source of information about the LVO status. A CAT I procedure is rarely reported only LVO will be explicit reported.

 

Besides all that in a multi crew environment both pilots have to be LVO rated. In my case down to a DH of 50´(CAT IIIA) as well as the FO has to be CAT IIIA rated otherwise the flight will be limited to CAT I only.

 

Another general info, for a precision approach only a RVR is required. Ceiling and visibility is only required for non precision approaches.

 

CAT I approaches can be flown manually or with the autopilot, CAT II/IIIA approaches have to be autoland or flown manually with an single/dual HUGS equipped airplane.

 

Thankw mikey much appreciated for the input. So in the flight sim world you will get to decide when LVO are in force then :) i better read up more about the regs ;)


Vernon Howells

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Again, if you want to be meticulous about posting correct info here, it is not a fact.

 

I'll concede that, but you'll note that I wasn't speaking to the requirement for the legal ability to fly the approach. Rather, I was speaking generically. The only part that would prevent you from flying the approach in a legal sense would be visibility (unless you're flying Part 135, which is relevant to the NGX and requires both, see below text from an FAA FSDO). Both ceiling and visibility, however, are factors in continuing past the published minimums. Both can inhibit seeing the airport environment. One could have visibility of infinity, but if the ceiling was reported as overcast right at 200' AGL (assuming a standard ILS here), then no matter how legal your attempt to shoot the approach is, you're not going to have the proper mins to land. So, congratulations on your legal flying of said approach, but that ceiling is still a factor in actually landing.

 

So, unless you have a solution to running out of fuel, I'd suggest people look at ceiling as a minimum value. Sure, try the approach out, but I wouldn't be dismissing a low ceiling, which is what many here are doing.

 

Are both ceiling and visibility required in order for an FAR Part 135 air carrier pilot to initiate an instrument approach?

 

FAR 135.225(a) and 135.225(a)(2) forbid a Part 135 pilot from beginning an instrument approach unless reported weather conditions at the destination airport are at or above the authorized IFR landing minimums for that airport. So, even though ceiling is not a criterion on the approach plates, it must be considered by the pilot in his decision to initiate the approach, and in deciding whether the reported ceiling is above or below the decision height or minimum descent altitude for the approach. Similarly, FAR 135.225(b) forbids initiation of a final approach segment unless reported conditions are at or above minimums. Again, the pilot must know the reported ceiling and visibility before deciding whether that approach segment can legally be initiated.

 

This interpretation has been coordinated with the Air Transportation Division of the Flight Standards Service. We hope that this satisfactorily answers your question.

 

 

 

It is a minima for planning alternates and that kind of stuff, but it is NOT a minima for a CAT1 ILS approach.

 

See above. It's not a minimum for flying the approach, but it surely is a minimum for your ability to see the field and land at it.

 

And sign your posts per the forum requirements:

http://forum.avsim.net/topic/245586-you-must-sign-your-full-real-name-to-posts-to-use-this-forum-posts-without-names-will-be-deleted/


Kyle Rodgers

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There you have it, some FAA Part-135 regulation. So basically anything else only requires suitable visibility. The rest is just debating over semantics. I regard minima/minimums as the published minimums you require for the approach, otherwise a whole load of factors can be called minimums.

 

In my experience it often no problem to establish the required visual reference, even with OVC002 or VV001. Therefore, to regard ceiling or cloudbase as a minimum or deciding not to try an approach because of it (if you're not CAT2/3 capable), is not the smartest course of action (outside of Part-135). But that's just my point of view.

 

I think we can agree that the listed steps and limitations for a CAT1 approach are appropriate otherwise (unless flying Part-135)?

 

 

 

-John Smith

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The rest is just debating over semantics.

 

A debate that wouldn't have happened if this thread hadn't been brought up. As has been referenced in many other threads like this, these supposed "helpful info" threads end up bringing more confusion to the table. If someone who had a full grasp on the information was bringing this over and explaining it, it would be one thing, but that's not the case.

 

 

 


Therefore, to regard ceiling or cloudbase as a minimum or deciding not to try an approach because of it (if you're not CAT2/3 capable), is not the smartest course of action (outside of Part-135). But that's just my point of view.

 

As I've said several times now, I don't regard it (ceiling) as a minimum for attempting the approach (except as outlined for Part 135). I regard it as a factor that could cause an issue with completing the approach. If the ceiling prohibits me from seeing the field at my MDA/DH, then it's certainly an issue of minimums: the ceiling forced me to abandon the approach AoA the minimums (in this case, minimum altitudes).

 

Sure, semantics, but had this thread been brought in with the appropriate background knowledge instead of regurgitated from PPRuNe or similar sites, the discussion could have avoided that issue.


Kyle Rodgers

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