Aerial view (from control tower) of airport ramp marshal and airliner wing at London Heathrow airport. A ramp agent manages the start-up of a 747, standing on directional lines that help pilots navigate to specific locations around the airport of five terminals on a site that covers 12.14 square kilometres (4.69 sq mi). London Heathrow is a major international airport, the busiest airport in the United Kingdom and the busiest airport in Europe by passenger traffic. It is also the third busiest airport in the world by total passenger traffic, handling more international passengers than any other airport around the globe. From the chapter entitled 'Up in the Air' and from the book 'Risk Wise: Nine Everyday Adventures' by Polly Morland (Allianz, The School of Life, Profile Books, 2015).