Washington Dulles International Airport passengers. Dulles was once assigned the airport code DIA, with each letter corresponding to the initials of Dulles International Airport. However, when handwritten, it was often misread as DCA, the code for nearby Ronald Reagan Washington National Airport. It was later revised to IAD to avoid confusion. The airport's terminal complex consists of a main terminal and two midfield terminal buildings: Concourses A/B and C/D. The entire terminal complex has 123 gates and 16 hardstand locations from which passengers can board or disembark using the airport's plane mate vehicles. Conceived in early planning sessions in 1959, Dulles is one of
Norfolk International Airport which it is categorized as a small-hub primary commercial service facility. As per Federal Aviation Administration records, the airport had 1,606,695 enplanements in calendar year 2011, a decrease of 3.4 percent from 1,663,294 in 2010. , Norfolk International was ranked as the 70th-busiest airport in the United States and the fourth-busiest in Virginia in terms of passengers served annually following Richmond International, Dulles International Airport and Reagan National Airport. Southwest Airlines, Delta Air Lines, and American Airlines are the predominant users of the airport. Norfolk International Airport covers an area of 1,300 acres (526 ha) at an elevation of 27