Heathrow Airport is one of the 4 airports in London and it is the largest of all of them. It is principal and also the largest airport serving the United Kingdom. The airport is also the third world busiest airport on passenger traffic. The airport also handles more international passengers’ traffic than other airports in the world. The airport is operated by BAA which operates other six airports in the UK. It is also the primary hub that serves sever international airline including British Airways, BMI and the Virgin Atlantic which all operates domestic and international flights.