The public enclosure at Northolt Airport , Middlesex , London , is crowded with visitors every day . For the small sum of sixpence entrance fee , they get a good afternon's entertainment . There is a cafe , and a sandpit for the kids and there are always long queues waiting to be shown over some of the airliners . The unceasing arrival and departure of planes to and from all quarters of Europe is also a never ending source of interest . Some of the visitors viewing the indicator board at Northolt Airport . 4 May 1949