Southwest Airlines specializes in domestic travel and is based out of Terminal B at Washington Dulles International Airport (IAD). Southwest Airlines IAD Terminal The Dulles Aerotrain makes it simple to go to Terminal B, which provides easy access to the main terminal. It has a range of food and shopping options, free Wi-Fi, and self-check-in kiosks, among other contemporary conveniences. Southwest Airlines passengers can anticipate a seamless travel experience that includes plenty of seating, charging stations, and quick boarding processes. Arriving at least 90 minutes prior to your flight is advised in order to give yourself adequate time for security and check-in. All things considered, Southwest passengers at IAD have a convenient and easy experience at Terminal B.