Southwest Airlines Co. (NYSE: LUV) is a major U.S. airline, the world's largest low-cost carrier, headquartered in Dallas, Texas. The airline was established in 1967 by Herb Kelleher as Air Southwest
and then adopted its current name, Southwest Airlines, in 1971 when it began operating as an intrastate airline wholly within the state of Texas. The airline has more than 53,000 employees as of October 2016 and operates more than 3,900 departures a day during peak travel season. As of 2014, it carried the most domestic passengers of any U.S. airline. As of December 2016, Southwest Airlines had scheduled services to 101 destinations in the United States and eight additional countries. Service to both Grand Cayman and Cincinnati begins June 4, 2017. Southwest Airlines has only operated Boeing 737 jetliner models, except for the period from 1979 to 1987 when it leased several Boeing 727-200s from Braniff International Airways. As of January 2016, Southwest is the largest operator of the Boeing 737 worldwide, with over 700 in service, each averaging six flights per day. With the exception of the original -100 variant, and the Next Generation -600 and -900 variants, Southwest has operated every variant of the Boeing 737.