Welcome to Flightinfo.com

  • Register now and join the discussion
  • Friendliest aviation Ccmmunity on the web
  • Modern site for PC's, Phones, Tablets - no 3rd party apps required
  • Ask questions, help others, promote aviation
  • Share the passion for aviation
  • Invite everyone to Flightinfo.com and let's have fun

TWR visibility

Welcome to Flightinfo.com

  • Register now and join the discussion
  • Modern secure site, no 3rd party apps required
  • Invite your friends
  • Share the passion of aviation
  • Friendliest aviation community on the web
Register   Log in
F

fowingman

Well-known member
Joined
Feb 23, 2006
Posts
227
whats the rule on this?

visibility on the atis is 1/4 mile but the tower visbility is reporting 2 miles on the atis as well, can you start the approach (cat 1)

what about now if there is rvr on that runway and they are showing 2000, (my understanding is flight visibility so rvr woudn't really matter)
 
rvr is controlling if reported. the current report from the tower (verbal, over the radio) trumps the ATIS.
 
fowingman said:
whats the rule on this?

visibility on the atis is 1/4 mile but the tower visbility is reporting 2 miles on the atis as well, can you start the approach (cat 1)

what about now if there is rvr on that runway and they are showing 2000, (my understanding is flight visibility so rvr woudn't really matter)
Click to expand...


Visibility on an Atis or TAF is controlling to be dispatched to an airport.

To begin the approach touchdown RVR is controlling.

If no RVR is available then the visibility reported by the approach controller is controlling (they get it from the tower)

And if the RVR is below mins and you have the airport in sight, you cannot accept a visual
 
Ok, lets talk about t/o vis. Lets say that tower is calling the tower vis below t/o mins but the runway touchdown point is above mins but the roll out is below mins.
 
Thedude said:
Ok, lets talk about t/o vis. Lets say that tower is calling the tower vis below t/o mins but the runway touchdown point is above mins but the roll out is below mins.
Click to expand...

In this case, you would be using RVR. RVR is controlling. It would not matter what the tower vis is.
 
Ops Specs...

This sort of thing is in the ops specs, but they are all pretty much the same. If the ops specs allows you to use RVR, then it is controlling.

Think of it this way:
-The tower cab is lost in a bank of fog, but the fog only covers up the top of the tower. Maybe you get below the 300 ft. level and it is totally clear underneath.
-The RVR in in this case would be much more useful to what you will see at DH, while the top of the tower is totally obscured. You can have times like this in real life, and the FAA wants to give you another measure of visibility to rely on to shoot an approach and land.
 
We are allowed to do contact approaches 121. However by the time you review all of the requirements for the approach might as well have shot an IAP! Have to have above cat 1 circling vis for an IAP to the airport, have the airport in sight or be below reported ceiling and on an IAP inbound course with visual ref to navigate, have VFR charts, ect....
 
Thedude said:
Ok, lets talk about t/o vis. Lets say that tower is calling the tower vis below t/o mins but the runway touchdown point is above mins but the roll out is below mins.
Click to expand...

You talking about RVR below landing mins for that runway (IE 1800) or you talking about RVR below low vis t/o limits (IE 600)?

If you are talking about below 1800RVR then I'd say you can go if your ops specs allow it as long as you get a t/o alt.

If you are talking about less than 600 RVR then you can't go if one of them is below 600, however you can go if one is inop and you are able to meet all of the 600/600/600 t/o req's in your ops specs.
 
MJ42 said:
At the 121 airlines I've been at(3) none were authorized to do contact approaches. Anyone know of a 121 carriers ops specs that allow these? I don't.
Click to expand...

Its been a long time now, but I think when I was at Colgan we could shoot contact approaches. I even remember being able to go VFR if you could get the dispatcher to agree to do it VFR, we could also cancel IFR while still in the air and often did while going into most of the smaller outstations.

At my current airline we can't do any of that. Shoot we can't even shoot NDB apps anymore, or do circ apps when the wx is below VMC, or even shoot a vis app if the tower is closed. So I don't know if Colgan is "crazy" or if my new place is conservative to what most other airlines out there do.
 
great cornholio said:
Its been a long time now, but I think when I was at Colgan we could shoot contact approaches. I even remember being able to go VFR if you could get the dispatcher to agree to do it VFR, we could also cancel IFR while still in the air and often did while going into most of the smaller outstations.

At my current airline we can't do any of that. Shoot we can't even shoot NDB apps anymore, or do circ apps when the wx is below VMC, or even shoot a vis app if the tower is closed. So I don't know if Colgan is "crazy" or if my new place is conservative to what most other airlines out there do.
Click to expand...

Even though they are 121, turbo prop operators have different rules than jet operators.
 
fowingman said:
so whats the deals


twr vis is 1/2 mile
rvr touchdown 1/4 mile


legal (cat 1)??
Click to expand...

RVR is reported in feet not sm so you will see something like RVR 1200. RVR is controlling only for the runway it is installed on not the entire airport. From what I've seen it is very rare (not sure if I've ever seen it even once) where an airport has RVR and is reporting it on all runways. If you look at approach plates you will see that there is a listed min for both vis in sm and RVR in feet. There are a lot of apps out there that have mins listed as 1/2sm or 1800 RVR. So lets say they are reporting vis of 1/2sm and 1R RVR is 1000. You can't shoot the ILS for 1R because the RVR reported for 1R is less than 1200. However if 1L is long enough to land on or if the wind will let you land on 19L (and it isn't reporting an RVR) then you can shoot the ILS for either of those runways because you have the 1/2sm.
 
What if there is No RVR?
Atis is calling 1/4 mile.
Tower Vis is 2miles.
Need 1/2 mile for the approach.
Part 121 operation.
 

Share this page

Latest posts

Latest resources

Latest media

Carbon Cub FX-3 Shenandoah Valley
Carbon Cub at Kittyhawk
FX-3 in the backcountry
IFR Panel in a Carbon Cub FX-3
Cub-Provo-UT-c.jpg
Back
Top