Drone Closes World's 2nd Busiest Airport

London had another airport-drone mess on its hands Tuesday, but this time the problem was much bigger. Heathrow Airport stopped all departing flights for roughly an hour because of a drone sighting, reports the BBC. A rep for the airport described it as a "precautionary measure." Last month, a similar issue snarled air traffic at Gatwick Airport, also in London. Heathrow, however, is much bigger. It is not only the busiest airport in Europe, it is the second busiest in the world in terms of international passengers, per the Independent. Only Dubai International sees more global travelers. (At US airports, TSA screeners are calling in sick.)