So as I stated in an earlier post, I believe that RVR will always be reported with a runway number preceding it. That is the runway it is valid for.
The argument that the RVR for 18 can not be substituted for runway 36 is corect. After all if the RVR for runway 18 is reported as 550m then one can never assume that the RVR for runway 36 will also be 550m since that threshold is a large distance from the point where the RVR 18 is measured.
However, in multiple RVR situations when the RVR is taken at 3 locations the RVR indication will be representative of the RVR at that part of the runway.
So if the RVR is reported as Runway 18 - 150, 350, 550 it is resonable to expect that the RVR for 36 - will be 550, 350, 150.
If I was to follow 411A's advice then how would I ever cope with the following:
Landing runway 36. RVR 36 = 550, 125, 75
Roll to the end required, turn in the turning circle and taxi-back to only available LVP exit at threshold 36.
411A says that if I need 75m to taxi then once I get to the turning circle I can not taxi back along the runway because while the stop end RVR 36 is 75m I can not use this as being the RVR in the opposite direction and therefore I don't have the required RVR to taxi back along the runway.............yea right!
Naples being the example chosen does not have an RVR measurament at the threshold of 06 / stop end of 24. As far as I am aware there is no authorisation for anyone to conduct lower than CAT1 approaches and therefore it is entirely logical that money is not wasted on installing and maintaining equipment that is not required. There is an ILS on 06 but this is not the preferred runway and looking at the location, when the winds require 06 to be used it is unlikely that fog / low cloud will exist.
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As far as I can tell, 06 has 510 metres of approach lights and the ILS has a DH of 396.
Looking at EU-OPS, (old Appedix), CAT 1 Precision Approach, Intermediate Facilities, DH 310 and above then we need an RVR of 900m. The Italian Authorities have helpfully also done the calculation and state clearly in the AIP that an RVR of 900m is required for ILS 06.
The new appendix requires an RVR of 1400m. Until 2011 operators can continue to use the old appendix and so it will be interesting to see if ENAC changes the 900m RVR restriction to 1400m when everyone has to follow the new appendix.
So going back to what Michelda said;
It happened to me one year ago.......rvr requested 900, vis 400 (night flight) rvr mid point 200 stopend 400. Ils on other side u/s. Nice flight at 3.30 lt......
So to answer the original question - you use CMV to decide if you can make the approach (avoid the approahc ban). At DA(H) if you have the required visual references (and they are maintained) then you can continue to land.
The mid-point RVR and the RVR at the other end of the runway are of interest in terms of the roll-out and most operators will use a minimum of take-off minima for the mid-point (where the aircraft is faster than 60Kt) and something like 75m (or the taxi limits) for the other end.