United Airlines' hub at Dulles International Airport (IAD) has long been on the cusp of something big. United Airlines planes at Dulles International Airport. UNITED AIRLINESThe redevelopment will add an estimated 5 million square feet of additional terminal and concourse space for travelers. While routes range from John Wayne Airport (SNA) in Southern California to Keflavik International Airport (KEF) in Iceland, one of the more significant additions comes in December when flights to Rafael Nunez International Airport (CTG) in Cartagena, Colombia, begin. Cartagena is notable as one of United's newest Latin American destinations, with the airline choosing Dulles International Airport (IAD) for its new nonstop service rather than Newark Liberty International Airport (EWR), its New York-area hub.