An El Al London-bound flight had to return to Israel on Thursday due to a cloud of volcanic ash covering large parts of Northern Europe and seriously disrupting air travel in the area.The cloud formed after a huge eruption of a volcano in Iceland earlier this week. Authorities in Britain and Norway shut down Europe's busiest airport at Heathrow and canceled hundreds of flights.Britain's Civil Aviation Authority said non-emergency flights would be banned until at least 6 p.m. (1700 GMT, 1 p.m. EDT). Irish authorities also closed their air space for eight hours.London Heathrow, Europe's business airport, handles upwards of 1,200 flights and 180,000 passengers per day. The closure also affected London's second- and third-largest airports, Gatwick and Stansted. It was not immediately clear when flights would resume.With the major trans-Atlantic hub at Heathrow closed, dozens of flights to the United States were on hold, and cancellations spread across the continent to major hubs at Brussels, Amsterdam, Geneva and Paris, where flights heading north were canceled until midnight.
