Thought I could avoid this new approach ban but today it caught up with me. The situation as presented to us made us think and delve into the books..albeit quickly and not at a great time. Inbound YUL on the star, atc advised us "...RVR runway 24r is 1000 feet but ground visibility is 3 miles. Two aircraft landed with those conditons and reported that the runway was in sight 3 back but that vis was lower once on the runway. What would you like to do?" My first thoughts were, it's below limits so we can't do the approach. However, it was a surprise to hear that two aitcraft approached and landed under those conditions. We looked it up because we were momentarily confused and what we found was that RVR takes precedence over runway and over ground vis. We abandoned the approach and landed on 24L. Just curious why does ATC allow approaches to occur if the ban is in effect and what would they do if they thought that the pilots had violated the ban?

I might be mistaken, however I think that when an airport is afflicted with low visibility, flights that land and depart are audited. No one will stop or prevent you from taking off or making the approach. However, the folks at Aviation Enforcement review the movements and if they find that an operator or pilot does not have the authority to have done the approach or take-off it is violation time.

Correct me if I`m wrong but if you read further it says that if ground vis is reported higher than rvr then you have a localized phenom and the reported vis takes pres.

I'll have to re-read but I'm sure our manual does not say that. I talked with a Standards guy and he agreed with what I read and interpreted. If there is a further info that is not in our manual then our manual needs to be changed. Cheers.

A lot depends on your OPS manual as the mins might differ from "standards"

"a localized meteoroligical phenonmenon is affecting the ground vis to the extend that the vis on the approach to the runway of intended approach and along that runway, as observed by the pilot in flight and reported immediately to ATS, if available is equal to or greater than the vis specified in the CAP for the instrument approach procdeure conducted..."

Is this the clause we're thinking about?

Ran into the same problem.
As far as I'm conserded, shoot the approach.
If Atc says you can go for it,the chances of mising a ILS approach is rare.
Stop worrying about intrapment,you need a GD transport Guy to figure the Reg's out sometime.
I made it in with a RVR of 1200 and my ass didn't even Puker.

mmmm...lets see...RVR takes presidence unless ground visibility is greater than RVR readings by ATC, or by FSS not by pilot issuance...also not to forget that the basic RVR approaches for PRIVATE guys is 1200 RVR and 1600 RVR for commercial operators unless specific in your OPS manual with an OPS SPEC....
cheers

cmadude wrote:mmmm...lets see...RVR takes presidence unless ground visibility is greater than RVR readings by ATC, or by FSS not by pilot issuance...also not to forget that the basic RVR approaches for PRIVATE guys is 1200 RVR and 1600 RVR for commercial operators unless specific in your OPS manual with an OPS SPEC....
cheers

cmadude, so if the RVR is 1000 and you need 1200-1600 (ops spec or not) to land in XXX, and the pilot reported seeing full length of the runway 3 miles final and landed, he/she violated rules because RVR was 1000 and takes precedence over ground vis which was 1/8 as per TWR?

Simple way to remember all this --- RVR is king -- better land on a runway with no RVR -- hard to do in YUL --

After re-reading my manual for the third time, I can see no let that allows for a localized event. If the ground vis is greater than the RVR is does not matter according to my COM. I have to follow my COM as they are TC sanctioned documents. It's too bad. On the other hand, if I were to ignore it and shoot the approach as someone suggested above, I would be opening myself to a can of worms that would be irresponsible to myself, my guests, and my company.

Thanks for the input guys.

Great post the SMS people would be proud

I would have to agree with “CCR” with that example.
As far as the exemptions for “localized phenomenon” I believe it does not apply to RVR.


http://www.tc.gc.ca/CivilAviation/comme ... AC0237.htm

The following exceptions to the above prohibitions apply to all aircraft when: (FROM TC AIM RAC 9.19.2.3)

a) the visibility report is below the required value, and the aircraft has passed the FAF inbound, or where there is no FAF, the point where the final approach course is intercepted;

b) the pilot-in-command has informed the appropriate ATC unit that the aircraft is on a training flight and that the pilot-in-command intends to initiate a missed approach procedure at or above the decision altitude (height) [DA(H)] or the MDA, as appropriate;

c) the RVR is varying between distances less than and greater than the minimum RVR;

d) the ground visibility is varying between distances less than and greater than the minimum visibility;

e) a localized meteorological phenomenon is affecting the ground visibility to the extent that the visibility on the approach to the runway of intended approach and along that runway, as observed by the pilot in flight and reported immediately to ATS, if available, is equal to or greater than the visibility specified in the CAP for the IAP conducted; or

f) the approach is conducted in accordance with an Operations Specification issued in accordance with CAR 703, 704 or 705.

Approach ban priority ONE -- RVR

In Canada, RVR transmissometers have been replaced with RVR sensors. RVR is displayed to ATS as a mean value of a one minute sliding window that is updated every 15 seconds. Although the sensor has a one foot accuracy, the RVR displayed to ATS is as follows:

• between 300 to 1200’ – 100’ increments
• between 1200 to 4000’ – 200’ increments
• between 4000 to 6000’ – 500’ increments

Approach ban priority TWO -- Runway Visibility

The concept of runway visibility has been added to the regulations. The purpose of runway visibility is to determine and report a visibility at the touchdown zone of a runway that is not equipped with or is not reporting an RVR. An instrument rated pilot or a qualified person can assess runway visibility when RVR sensor equipment is not available. In effect, a person is permitted to assess runway visibility from approximately the same position as an RVR A sensor installation. The following procedure is to be followed on how the when reporting the assessment of runway visibility.

1. Runway visibility is assessed while stationary at the runway threshold take-off point, at the taxiway holding position for the taxiway adjoining the runway threshold, or at a point adjacent to the runway threshold.

2. When assessing runway visibility, a pilot:

a. assesses, in the runway direction, the furthest visible runway edge lights or landmarks within 10 degrees of the runway centreline that can be seen and recognized;

b. from the assessment in paragraph (a), determines the distance (in feet) based on a 200 foot runway edge light spacing or using the applicable Aerodrome Chart published in the Canada Air Pilot (CAP); and

c. immediately reports the distance assessed to ATS, if available, or to the inquiring party, as the runway visibility along the specified runway in the following format:

“RUNWAY VISIBILITY, RUNWAY [runway number] ASSESSED AS [distance assessed] FEET AT [time] UTC”, to the nearest 100 foot increment.

3. If the runway visibility varies during the assessment, the pilot reports the lowest value observed.

4. The lowest reported value is 200 feet, with lower values reported as “…LESS THAN 200 FEET…”.

5. The highest reported value is 6,000 feet, with higher values reported as “…GREATER THAN 6,000 FEET…”.

Approach ban priority THREE -- Ground Visibility

Ground visibility is the prevailing visibility determined by an accredited observer or the visibility determined by an AWOS. Ground visibility determined by an accredited observer is as follows:

• between 0 to 3/4 sm - 1/8 sm increments
• between 1 to 2-1/2 sm – 1/4 sm increments
• between 3 to 15 sm – 1 sm increments

Ground visibility determined by AWOS is as follows:

• between 0 to 3/4 sm - 1/8 sm increments
• between 1 to 2-1/2 sm – 1/4 sm increments
• between 3 to 3-1/2 sm – 1/2 sm increments
• between 4 to 9 sm – 1 sm increments

you can quote all those rules but it boils down to the "ops spec" -- in the ops spec -- RVR is king

CCR,

Were you inside the FAF?
Was the RVR fluctutating?
Did you conduct this flight in accordance with CARS 703, 704 or 705?
What's stated in your ops spec?

sanjet wrote:cmadude, so if the RVR is 1000 and you need 1200-1600 (ops spec or not) to land in XXX, and the pilot reported seeing full length of the runway 3 miles final and landed, he/she violated rules because RVR was 1000 and takes precedence over ground vis which was 1/8 as per TWR?

Are you sure???

I sure get worried when transport puts out rules like this that have so much interpreted meanings...everybody seems to have a different take on the rules..

good luck!

Indeed -- this is one good example where the lobby groups got TC to completely bastardize something that could have been so simple. Just adopt ICAO standards -- 550 meters - no thoughts to the pilots -- maybe this is a way of getting the lost revenue back from the medicals -- march the guilty bastards in -- haha

niko wrote:

sanjet wrote:cmadude, so if the RVR is 1000 and you need 1200-1600 (ops spec or not) to land in XXX, and the pilot reported seeing full length of the runway 3 miles final and landed, he/she violated rules because RVR was 1000 and takes precedence over ground vis which was 1/8 as per TWR?

Are you sure???

I'm asking you LOL! I was baffled when I heard that on the radio. I can see how things can be so complicated here for nothing...

Outside the FAF
No fluctuations
705
RVR takes precedence over runway over ground; no lets for local phenom

...all pretty clear now.

An approach ban can be imposed, not only by RVR readings below specified values, but also by a reported runway visibility or a reported ground visibility below specified values.
An RVR report will take precedence over a runway visibility report or a ground visibility report.
A runway visibility report will take precedence over a ground visibility report.

Finally, if no RVR, runway visibility, or ground visibility is reported; there are no criteria to impose an approach ban. This concept is similar to the present Subpart 602 of the CARs approach ban, where if there is no RVR reported; there is no criterion to impose an approach ban.

What if RVR is fluctuating above and below min's?

No prohibitions to the approach if the RVR is varying between distances less than and greater than the minimum RVR

Swordfish54 wrote:No prohibitions to the approach if the RVR is varying between distances less than and greater than the minimum RVR

Do you have a reference for this?

matrix wrote:

Swordfish54 wrote:No prohibitions to the approach if the RVR is varying between distances less than and greater than the minimum RVR

Do you have a reference for this?

CAR 700.10 (3)

Where the visibility is less than the minimum visibility set out in subsection (1) or (2), as applicable, no person shall continue a non‑precision approach, an APV or a CAT I precision approach in an IFR aircraft unless

...

(c) the RVR is varying between distances less than and greater than the minimum RVR

The sub-paragraphs are all a series of cases, separated by the magic "or"

Thanks Aeros. Finding stuff in the CARS is a bit of a pain sometimes.

Here's my million dollar question(or whatever the fine is):

WHAT THE @#$! IS A FLUCTUATION?! How do you define it? if the weather was severe clear, and 20 minutes later 1/4 mile, isn't that a fluctuation? What if it stays at 1/4 mile for the rest of the day? At what point is it no longer a fluctuation if it ever was in the first place?

I'll bet the answer is similiar to the answer I get when I ask wtf an 'unforseen circumstance' is...