In December, a Flybe Airline flight from Cardiff, Wales, was preparing to land as scheduled at Charles de Gaulle airport in Paris when the pilot announced that they had to return to Cardiff because, he said, "Unfortunately, I'm not qualified to land the plane in Paris." Because of the heavy fog, the plane would have to be instrument-landed, and the pilot had not yet completed certification. [USA Today-Metro (London), 12-18-08]
Maybe it's just me, but I prefer my pilots to be certified for all circumstances that may arise while they are piloting my plane.
I understand there are always things you can't be prepared for....but fog?