RVR and DH

[scandinavian13 5,192]

For what it's worth, ATC-wise, RVR will be reported on frequency if it changes.  This is the same as when controllers say "attention all aircraft on frequency, information Echo now current: [changes in weather from info Delta]."

 

This may also be optionally added by the controller when clearing aircraft for the approach or landing.  It's not standard (though the 7110.65 3-10-1 lists it as "any supplementary information" as part of standard landing information), but some controllers do it just to ensure pilots have the most up-to-date information.  This is the same as when controllers say "wind 020 at 9, Runway 1R, cleared to land."  They would just add the RVR between the wind and the landing clearance.

 

Additionally, the controller does have access to all of the charts (to include company-specific procedures) at their console.  Depending on the facility, a controller will have some sort of tool to pull up all kinds of info.  Potomac Approach (PCT) has theirs up above the radar console, and it is able to display basic aircraft information, all charts for relevant airports, and even menus for local restaurants (PCT is in the middle of nowhere so they generally have to order in, and order early if it's going to get there by the time they take a break - even local restaurants that don't do delivery have worked out an agreement with them to help them out).

 

So, just in case you drop your coffee on your chart and ruin it, you could ask them ahead of time to verify the info and they could do it.

[Michael Moe 494]

DH is not reported by ATC, it is published on the chart for the approach in question...

Could not understand that either. That why i in the originale post mention that my ils charts always just state CATIIIB avaible or CATIIIA.

 

Thanks

 

Michael

[scandinavian13 5,192]

 

 

That why i in the originale post mention that my ils charts always just state CATIIIB avaible or CATIIIA.

 

...and at the bottom, there will be the requirements.  What it seems that you're not understanding is that CAT III approaches are approaches that were created for and are certified for zero vertical visibility.  As such, there's no DH (for CAT II, it's listed as RA here: http://155.178.201.160/d-tpp/1405/05100I1LC2_3.PDF; for CAT IIIa and IIIb, it only lists RVR - 700 and 600 feet, respectively).

 

In order to understand how to read charts, I suggest having a look at this:

http://www.vatusa.net/training/tiki-index.php?page=reading_instrument_approach_plates

 

If it says "CAT IIIb available" without any mention of RVR, chances are, it's on another chart and you're looking at the wrong one.

[Great Ozzie 101]

what has first priority during the FA? DH or RVR.

Both have "priority" when you have both.

 

Generally speaking, Three requirements need to be fulfilled to descend below DH / DA / MDA

 

• Flight Visibility (e.g. reported as RVR not below mins)

• Visual Reference to the Runway* (see below links as too long to list here)

• Continuously in a position to make a normal descent to landing (135/121 have an extra requirement)

 

§91.175 covers the specifics, particularly what visual references are acceptable.

 

§91.189 covers the specifics applicable to Cat II & Cat III approaches.

 

There's also mention in 91.189 regarding "operating an aircraft using a Category III approach without decision height" which goes right back to Col. Scott has previously covered.

 

 

That why i in the originale post mention that my ils charts always just state CATIIIB avaible or CATIIIA.

 

I am a bit curious which charts you are referring to.

[scandinavian13 5,192]

 

 

I am a bit curious which charts you are referring to.

 

Yeah, same.  It really shouldn't be this hard if it's the charts I'm used to.

[Fabo 213]

Guy should probably go watch Ralphs video as well.

[Michael Moe 494]

Yeah, same.  It really shouldn't be this hard if it's the charts I'm used to.

 

 

Hmm thanks . I use Navigraph charts and i dont see RVR under CATIII

 

Both have "priority" when you have both.

 

Generally speaking, Three requirements need to be fulfilled to descend below DH / DA / MDA

 

• Flight Visibility (e.g. reported as RVR not below mins)

 

 

 

 

So i am wrong when i say its up to captain to deside whether the RVR as stated by ATC is as it should be and i can continue my approach if at my DH i believe so ?

 

Some peoble her say i am not in charge of RVR measurement but if i am afterall (responsiblity) i need tor learn to measure the lights or whatever the airport is using from the pilot side.

 

Sorry for my stupid Questions . I do love your answers though. Much apreciated fellow simmers :-)

 

Michael

Guy should probably go watch Ralphs video as well.

 

 

I did twice :-) Can you explain me the DH he maid in the GOAround video and why? He was performing an Autoland in the Go/Around video

 

Thanks

Michael

[Great Ozzie 101]

So i am wrong when i say its up to captain to deside whether the RVR as stated by ATC is as it should be and i can continue my approach if at my DH i believe so ?

 

For this CAT III Part 121 stuff, I have no clue.  We need an adult to step in (RSR... Col. Scott...).  I do believe there is some requirement that reported visibility (e.g. RVR) has to be at or above the required visibility minimum on the approach chart in use to legally fly the approach.

 

Under U.S. Part 91 (basically "non-commercial" i.e. not charter and not airline) if the reported visibility is less than what is required on the approach chart, you can attempt the approach (iirc!) but if you land and there is a reported RVR of less than 2400' (and this referring to a CAT I ILS approach*) one is going to have a very difficult time demonstrating to the FAA the flight visibility was 1/2sm or better.  (Turn on that GoPro before the middle marker and have a good attorney  :lol:  ).  

 

 

Also, with respect to your chart, there should be one for the CAT III approach @ EKCH.  I found a Jeppesen that has the CAT II with minima the same as the Navigraph (although it did list a DA / DH also).  As an example, here is a link to a U.S. Government chart (pdf) for the Indianapolis (KIND) ILS RWY 5R (CAT II & III).

 

Google CAT IIIB EKCH and you should be able to find at least a Jeppesen pdf that includes the CAT II approach (I could not find the CAT III).  

 

Your questions are not stupid... some of this stuff can be quite complicated and it definitely going to vary on the type of operation.

 

-------------

*Not referring to the CAT I ILS to 1800'RVR

[RKOines 0]

Even though it has been mentioned several times above, I  would strongly suggest that if you have not taken this ground school course, it is well worth both the time and the money ($0.00):

 

http://forum.avsim.net/topic/440291-cat-iii-instructional-video/#entry2972723

 

Ron Oines

[scandinavian13 5,192]

 

 

Hmm thanks . I use Navigraph charts and i dont see RVR under CATIII

 

While my family is part Danish, they still confuse me from time to time.  There should be RVR listed in that block that says "available."  My guess is that it's on another chart that has "CAT III" as part of the title.

[Fabo 213]

RVR limit on lower bounds is quite often company and/or type specific, maybe that is why Navigraph doesn't include them?

In any case I show 75m RVR and no DH.

[scandinavian13 5,192]

 

 

RVR limit on lower bounds is quite often company and/or type specific, maybe that is why Navigraph doesn't include them?

 

Where did you learn that?  That isn't supported by any of the approaches I'm seeing over here.

 

Note the cross-cat  (approach cat, in this case) limits at the bottom:

http://155.178.201.160/d-tpp/1405/05100I1RC2_3.PDF

 

A, B, C, and D are all the same.  Sure, you can have modifications as approved in OpSpecs, but absent those, they're pretty standard as printed right on the chart.  At least over here in FAA land...

[Fabo 213]

 

 

Where did you learn that?  That isn't supported by any of the approaches I'm seeing over here.

 

Of course thay can't be under regulation minima.  Company minima or type minima (or airframe minima theoretically but by then we are probably talking about temporary revocation of LVP for MEL reasons) can be higher.

 

See this Air Berlin flightplan for example, specifying RVR limit of 300m as opposed to usual quoted CAT IIIa distance of 200 meters or CAT II distance of 400.

http://www.edi-gla.co.uk/fpl/view.php?fpl=155615

[Vargveum 53]

I will say it again. DH is linked to aircraft autopilot limitations and, as said, company SOP and aircrew qualifications. Nevertheless, DH cannot be lower than 50 feet if you don't have a fail operational autopilot. That's why you don't see it on the chart.

[scandinavian13 5,192]

 

 

That's why you don't see it on the chart.

 

Sure - we've already established that, I thought - the RVR should be listed, though.  Currently, there's not a single entry in that box other than "available."