Required RVR from chart is 550.
I don't have RVR reported, and VIS is 350.
I cannot convert in this case since the required RVR is less than 800.
This case I can only start the approach till the outer marker / equivalent point, and discontiue if not in sight?
I believe you are correct. To obtain a legal met vis for the approach, with no RVR available, you would have to convert 800M since that is more limiting than the chart requirement of 550M.
So, minimum MET VIS to proceed beyond the approach ban point would be:
400M at NIGHT
550M by DAY
If you get the RW visually by the Approach Ban point you would NOT be legal unless you declare/ are cleared for a visual approach with a minmum visibility/RVR of 800m to allow for the shallow fog risk at the threshold.
Last edited by Stanley Eevil; 21st October 2012 at 10:20.