LONDON, According to a provisional world statistics from "Airline Business" magazine, London airport's Heathrow is into fourth place for passenger traffic: the airport handled 30.8 million passengers in the first half of this year, 11.5 per cent up on its January-June 1999 total. Atlanta's Hartsfield (40.6 million passengers) was the busiest airport in January-June 2000, with Chicago's O'Hare second...