RVR/Vis for take-offs/approaches

R

rmp339

New Member
Currently studying RVR/Visibility, and I'm confused with a couple of sample questions given regarding take-off and approach. example:

Prior to receiving takeoff clearance, tower advises that RVR is 2200 with a reported ground vis of 1/2 mile.

in this case, would take off be

authorized because of a localized phenomena is deemed to be occuring?

or authorized because RVR 1200?

OR would takeoff be unauthorized because RVR takes precedence over ground vis?

or unauthorized because both RVR and ground vis must be at or above specified takeoff visibility



Another question that I can't figure out is based on landing/approach. example:

when approaching/landing, RVR required is 1800. But your RVR is fluctuating between 1400 and 2200. ground vis is 1/2 mile

Would you be able to approach/land due to the 1/2 mile ground vis, REGARDLESS of what the RVR is?

Would you be able to approach/land due to the fact that RVR fluctuates above the required RVR REGARDLESS of what the ground vis is?

or is there another reason for being able to approach/land or not being able to approach/land?


If anyone could give some input/answer, or help clear this up for me that would be greatly appreciated.

thanks!
 
From what I've seen, the first question depends on the qualifications for the pilot and/or company minimums. One guy might be able to depart with 1,600 feet while another might need 1,800 feet.

Again from what I've seen, both minimums have to be met, but the one that always seems to result in landing or not is the RVR. You'll see one guy land then the RVR drops below minimums and the next guy will go around.

In sure some pilots will be in here soon to give you a much better answer than mine, but I figured I'd give you what I've seen happen.
 
RVR is always controlling for the runway associated with it. For both takeoff and landing.


Now the RVR you are required to land or takeoff is dependent on what your company is authorized for. Look at C079 for takeoff and C052 for landing.
Lets use PDX ILS 10R for an example - http://155.178.201.160/d-tpp/1403/00330IL10R.PDF
When you check on with tower, if vis is that low they're going to give you the current RVR as they read it right now, or ask. They say 1800 or more, you can continue past the FAF, and now it's flight vis, so even if the RVR goes down to 1200 after the FAF, you may continue. If the RVR was 1200 when you reached the FAF, go missed. Only the landing RVR is controlling. Mid and rollout are irrelevant.
Mind you that's all CAT I.

For takeoff, lets say your company is authorized to 6-6-6, which is common for 2 pilot operations. Now we look at the back of the Jepp 10-9 page(I have no clue here with NACO charts, and they're terrible and shouldn't be used anyways). I think pdx 10R is authorized to 5-5-5 at least. So when we're #1 for takeoff, tower calls and says RVR is 600, 700, 600, since we're authorized to 6-6-6, we can go. Mind you there are other conditions that need to be met like lights working, departure alternates, etc.

Mind you this is all irrelevant for part 91.
 
z987k said:
RVR is always controlling for the runway associated with it. For both takeoff and landing.


Now the RVR you are required to land or takeoff is dependent on what your company is authorized for. Look at C079 for takeoff and C052 for landing.
Lets use PDX ILS 10R for an example - http://155.178.201.160/d-tpp/1403/00330IL10R.PDF
When you check on with tower, if vis is that low they're going to give you the current RVR as they read it right now, or ask. They say 1800 or more, you can continue past the FAF, and now it's flight vis, so even if the RVR goes down to 1200 after the FAF, you may continue. If the RVR was 1200 when you reached the FAF, go missed. Only the landing RVR is controlling. Mid and rollout are irrelevant.
Mind you that's all CAT I.

For takeoff, lets say your company is authorized to 6-6-6, which is common for 2 pilot operations. Now we look at the back of the Jepp 10-9 page(I have no clue here with NACO charts, and they're terrible and shouldn't be used anyways). I think pdx 10R is authorized to 5-5-5 at least. So when we're #1 for takeoff, tower calls and says RVR is 600, 700, 600, since we're authorized to 6-6-6, we can go. Mind you there are other conditions that need to be met like lights working, departure alternates, etc.

Mind you this is all irrelevant for part 91.
Click to expand...
Oh come on. Naco charts aren't that bad

Good post.
 
z987k said:
RVR is always controlling for the runway associated with it. For both takeoff and landing.
Click to expand...

+1

Visibility is taken from the tower cab, RVR from the approach end of the runway usually near the touch down area so it's much more accurate.

z987k said:
Mind you this is all irrelevant for part 91.
Click to expand...

When I was at KFAT the RVR would get down around 600' or less. The DC9, 727, 737s that spent the night (PSA, Air California, Hughes Air West and United) would depart empty under part 91 to fly the rest of their route. Often they would tug them all the way to the run-up pad. Ground control would have to wait for the tug to clear taxiway before the next aircraft could go out. Once in awhile a call came on the radio, Ground, I'm not sure where I am, I'm lost. The first response from ground was always the same. What color is the line?

Hard to believe for those who have never experienced Tule Fog.
 
fholbert said:
+1

Visibility is taken from the tower cab, RVR from the approach end of the runway usually near the touch down area so it's much more accurate.
Click to expand...

So in this case, would you say the most accurate/correct answer would be that takeoff should NOT be authorized because RVR takes precedence over ground visibility?
 
rmp339 said:
So in this case, would you say the most accurate/correct answer would be that takeoff should NOT be authorized because RVR takes precedence over ground visibility?
Click to expand...
Always. That's what is meant when "RVR is controlling" is said.
 
z987k said:
For takeoff, lets say your company is authorized to 6-6-6, which is common for 2 pilot operations. Now we look at the back of the Jepp 10-9 page(I have no clue here with NACO charts, and they're terrible and shouldn't be used anyways). I think pdx 10R is authorized to 5-5-5 at least. So when we're #1 for takeoff, tower calls and says RVR is 600, 700, 600, since we're authorized to 6-6-6, we can go. Mind you there are other conditions that need to be met like lights working, departure alternates, etc.

Mind you this is all irrelevant for part 91.
Click to expand...

I'm Jepp-inept, so mind if we go ahead and have the NACO discussion? NACO is going to post the landing mins at the bottom OR non-standard takeoff mins at the top left. For landing mins (listed in miles), do you only adhere to landing RVR? What about takeoff mins? I don't think NACO publishes a comparable 6-6-6 number per airfield beyond the takeoff/landing mins published.

I could also be completely wrong. Halp.
 
NewYorkophile said:
I'm Jepp-inept, so mind if we go ahead and have the NACO discussion? NACO is going to post the landing mins at the bottom OR non-standard takeoff mins at the top left. For landing mins (listed in miles), do you only adhere to landing RVR? What about takeoff mins? I don't think NACO publishes a comparable 6-6-6 number per airfield beyond the takeoff/landing mins published.

I could also be completely wrong. Halp.
Click to expand...
Which is why you shouldn't use NACO.
 
You must log in or register to reply here.
Back
Top