In the novella, there is no wind, not even a light breeze when they are in Bangor. Since this was virtually impossible to execute for the movie they simply created dialogue to explain that even with a wind down here the clouds are not moving.
The aircraft used in the movie (Lockheed L-1011-385-1 TriStar (Reg No. N31018)), first flew on 10/02/1974, and was delivered to Trans World Airlines on 23/03/1974. Following filming of The Langoliers, the aircraft was re-registered as SE-DSC, and sold to Air Ops of Sweden (delivered 18/03/1995). It was broken up for scrap at Bournemouth, UK, 1996.