Originally Posted by
TangoAlphad
Depends when you are told. If you are told the RVR has dropped below the minimum RVR required before the outer marker / 1000AGL you are required to discontinue the approach as per the approach ban. However once past this point you are allowed to continue to DA and take a looky and land or G/A depending if you get the required visual references or not.
Per FAA rules, he already has the required visual reference - approach lights. He can continue until 100', at which time he must have a runway reference in sight.
Dunno if EASA or CAA has different rules AFTER visual reference is acquired...