In just four months, the world's first jumbo jet goes into regular service over the Atlantic. Already 200 have been ordered by the world's airlines. Each is designed to carry nearly 500 passengers. The jumbo has been called a 'pilot's dream'. Will it also be an airport's nightmare? By next year, half a dozen of the giants may be queuing at peak hours to disgorge their passengers at London Airport. Round the world, airports face their biggest jam in history. Jumbo jets will revolutionise airport design. But they may also speed up other travel developments, with far-reaching effects on the design and peace of our cities. Bigger planes still are on the way. How many is too many in an aeroplane? Produced by Michael Weigall.