I flew a Citation from Bournemouth calling in at Bristol Filton. The landing into Filton was right on minima at Dusk with the whole of London going down fast.
I had to position to Southend which being by the coast was clear in this situation and forecast to stay clear.
A night takeoff from Filton in fog and regular updates on the Southend weather sounded good. I was handed over to Southend only to be told that one end of the runway was fog bound followed by the rest was down to 200 metres in the course of being 12 miles out and 5 miles out .
Biggin is higher up and was still clear so elected to divert there landed at Biggin with patches of fog on the runway.
Fuel is your friend so always take on much more than you need if in doubt. Do not rely on one alternative but have a number of potential plans as fog is very fickle.
With land bound fog often coastal fields remain clear and visa versa.
Fog can be extensive. On another trip I flew to Aberdeen. There was no glimpse of the ground the whole way up. The whole of the UK was in fog with only the tip of Scotland fog free.
Alternative was Ireland which was totally clear so be prepared to divert some way if you have to do the trip.
Localised fog can be very thin and near river or water or in low lying areas and maybe only 10 foot thick other fog can go into hundreds of feet thickness and cover an extensive area.
Pace
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