What is the Min Vis for visual app ?

[kuwait340]

hello all....

i need to know the min vis for the visual approach...and is different from day to night ?

i have one paper on that issue and it says on it : min RVR 800m or vis 1500m (day) , 5000m (night) ...

but this paper in not official paper....

the question is for cat c a/c ( vapp 121-140kts )

any comment ?

[OverFlare]

I don't know if there's a general answer to this question.

We would look in the performance manual for minima at each airfield. Sometimes a visual approach might require 10km by day or by night. I've seen some that require only 800m but, with a circling height of 1500ft I don't fancy my chances much if the vis is that low.

[BOAC]

Most JAROPS airlines specify 800m (which is sporty!). 2400m for circling approaches.

[I-2021]

Hello Kuwait340,
I am sure that your OPS manual covers this aspect unless Visual Approach are prohibited by your Airline :)
Try to have a look there because your Airline's SOP could be more restrictive than the JAR-OPS requirements.
Bye.

[Inverted81]

I believe the UK AIP states a min RVR of 800m.. or met vis equivalent if RVR not available.

But SOP's for individual companies may well be higher than this. Talking from trainee ATCO POV...... :rolleyes:

[kuwait340]

mmmm....i will dig into the company sop ....and see what they got for this .

thanks

[Pontius's Copilot]

Minimum visibility (that's Met Vis, not RVR) for a CIRCLING APPROACH found in PANS-OPS Part 1 - Section 4 Chapter 7, page 5 (and also Appendix 1 to JAR-OPS 1.430) for aircraft categories A to D: 2400m for Cat C.
Minimum RVR for a VISUAL APPROACH in Appendix 1 to JAR-OPS 1.430: An operator shall not use an RVR of less than 800m for a visual approach - no other guidance given. From memory the old UK CAP 360 document suggested something like the higher of 800m or the highest non-precision minimum RVR for a straight-in approach to the intended landing runway.

[Charly]

Normally a visual approach is the completion of an instrument approach by visual means. So there cannot be a general minimum for visual approaches. It always depends on the Instrument Part which brought you there.

There are approaches, where the instrument part brings you to a fix/VOR/NDB positioned 2, 3 or even 5 NM out from the field. In order to continue, you have to have the RWY in sight.
Now you need at least 2, 3, or even 5 NM visibility for this perticular approach.

For an ILS this means: The "Instrument part" brings you into a position 200 ft above the RWY (decision alt), or ~ 0.6 NM from the Loc Antenna. 0.6 NM are actually roundabout 1100 m. So the 800 m RVR are the absolute minimum to complete this approach by visual means.

Especially for ILS Approaches check your company procedures for the following: What exactly means RWY in sight? Threshold lights? Approach lighting? And which part thereof? How many Lights?

Circling: The only reason for the 2400 m minimum during these kinds of approaches: it shall give you the chance to maintain visual contact with the RWY at all times during the manoever.
But if you look at those 2400 m and your lowest minimum of 600 ft, you'll soon find out, that this is practically impossible. So make it 3000 m for your own decision making, before you accept a circling approach.

Regards Charly

(I'm not sure, if your company has approved them, but if they did: check NCE VOR Approaches 22L/R and VOR 04L/R for nice examples: high minimum and a visual track to follow therafter)

[kuwait340]

nice inputs...

thanks

[bookworm]

Normally a visual approach is the completion of an instrument approach by visual means. So there cannot be a general minimum for visual approaches. It always depends on the Instrument Part which brought you there.

PANS-ATM would disagree with you. A visual approach can replace an instrument approach in its entirety:

Visual approach. An approach by an IFR flight when either
part or all of an instrument approach procedure is not
completed and the approach is executed in visual reference
to terrain.

It gives no minimum visibility, simply saying:

6.5.3.3 An IFR flight may be cleared to execute a visual
approach provided the pilot can maintain visual reference to
the terrain and:
a) the reported ceiling is at or above the approved initial
approach level for the aircraft so cleared; or
b) the pilot reports at the initial approach level or at any
time during the instrument approach procedure that the
meteorological conditions are such that with
reasonable assurance a visual approach and landing
can be completed.

As previously quoted, JAR-OPS1 does specify a minimum:

(g) Visual Approach. An operator shall not use
an RVR of less than 800 m for a visual approach.

[santiago15]

Bookworm,

I would agree with you.

I was once told, in the early days of flying training, that the 800m minimum is to cater for the case where the R/W is covered in shallow fog (coastal airfield?) Thus, you would be perfectly able to make a visual app (above the fog - slant vis etc.) but the vis would decrease in the final stages in the app.

S15

[Charly]

Thank You, Bookworm for clarification. You are perfectly right, as I excluded the nonexistance of an instrument approach in my post. What I ment, is that you approached the airport as an IFR flight, so the visual approach can as well just complete an ifr flight (not only the approach) by visual means.
The "runway in sight" thing for continuation of a visual approach in my post above, is an operator requirement to fill up the vacuum left by PANS ATM in the chapter: "that the meteorological conditions are such that with reasonable assurance a visual approach and landing can be completed"

Regards Charly

[flyboyike]

Under FARs, visuals can only be done in VMC, which is not less than 3SM vis and 1000' ceilings.