Actually I worked at Heathrow or to put it more accurately out of Heathrow for more than thirty years. It would be fair comment of course that anyone on the spot in ATC every day would have a more comprehensive view than mine. Even so I would call 75m RVR (as opposed to met visibility) a rare event - middle of the night perhaps ? Below 75m RVR would have stopped operations for everyone and I don't recall that myself.
Last edited by Tagron; 11th Apr 2013 at 17:18.
Reason: Minor deletion