Southwest now cleared for international departures by Laura Lorenzetti @FortuneMagazine July 1, 2014, 8:34 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Southwest Airlines LUV is going international for the first time ever Tuesday in its signature red, blue and orange Boeing 737 planes. The Dallas, Tex.-based airline will now fly outside of the United States to tropical destinations already served by subsidiary Airtran, which Southwest acquired in 2011, in part to gain access beyond the border. The first international flight will head to Aruba from Baltimore/Washington International Airport (BWI). Five more flights will follow Tuesday: BWI-Montego Bay, Jamaica, Atlanta-Aruba, Atlanta-Montego Bay, Baltimore-Nassau, Bahamas and Orlando-Montego Bay. Southwest, founded in 1967, has grown to be the largest airline shuttling passengers within the United States. However, its international presence is dwarfed by larger rivals such as Delta DAL and American Airlines AAL . Going international, and therefore head-to-head with legacy rivals, is Southwest’s opportunity to drive future growth, CEO Gary Kelly told USA Today. The low-cost carrier plans to expand more overseas to Canada, the Caribbean, Mexico, Central America and as far as the northern tier of South America. Kelly is also considering expanding service beyond the contiguous U.S. to Alaska and Hawaii. Until then, Southwest will continue converting international Airtran routes, starting with Milwaukee and Orange County, Calif., flights to Mexico, opening in August. More international flights out of Austin, Chicago Midway and San Antonio will be added in early November.