Have fond memories of holding awaiting RVR improvement on 24 [ now 23 ] at GLA . Watch a patch of fog drift from threshold of 06 [05 ] towards the Clyde . Skipper calls in the improvement , RVR picks up for 06 , we position downwind for 06 , base , finals ... see the fog reverse direction and march down the runway to meet us . RVR down , Wave off , back upstairs to wait until it all melts/ burns off ; ignoring any further ' suckers gaps ' .
And yes it was a Trident . Fog forcasting is still an imprecise art , local knowledge very necessary . Temp / dewpoint closing , mixing breeze , lack of winter sun's heating , take lots of fuel .
Back then , 'tho no one else could do it . So no delays LHR - Scotland return twice , 4 @ low vis take offs , 4 @ 12' Radio DH , and 75m. RVR landings . All on Schedule , drive home very slowly and cautiously .
rgds condor .