Originally Posted by
Del Prado
ILS has lower minima (including CAT 3 autoland). If the bigger airports relied solely on RNAV approaches then no one would land when visibility went below 1400M or cloud ceiling was below 700’. CAT 1 ILS approaches can be carried out in 550M visibility and 200’ cloud ceiling.
The ability to fly a LPV procedure considerably lowers the OCA, for a CAT C aircraft on runway 02 the OCA is 415 FT. Had the obstacle environment been better (ie no hill or trees) the OCA would have been even lower.
From what I recollect the visibility/RVR minima takes into account many factors, including OCA and the length of approach lighting on the landing runway. I suspect that could result in less than 1400 metres.
See my link in #402