Southwest Airlines Co. (NYSE: LUV) is an American low-cost airline. The airline has its headquarters on the grounds of Dallas Love Field in Dallas, Texas. Southwest is the largest airline in the world by number of passengers carried per year (as of 2009) Southwest maintains the third-largest passenger fleet of aircraft among all of the world's commercial airlines. As of May 3, 2009, Southwest operates approximately 3,510 flights daily. Southwest Airlines has carried more passengers than any other U.S. airline since August 2006 for combined domestic and international passengers according to the U.S. Department of Transportation's Bureau of Transportation Statistics. Southwest Airlines is one of the world’s most profitable airlines, posting a profit for the 37th consecutive year in January 2010.