SidStar
Yep, the assesment from the flightdeck rule can be very useful. In MUC last year as we lined up for an evening departure on RW26R the tower said "RVR 300m". Only thing was that we could see the other end of the runway. The heat from the runway was keeping it clear, but the transmissiometer (RVR measuring device) was sat in the patchy fog that was forming over the grass beside the runway.
T'bug
