
The airline began service June 18, 1971 with flights to Houston, Dallas, and San Antonio. It has grown to become the fourth largest U.S. airline (in terms of domestic Customers carried). Yearend results for 2001 marked its Airlines' 29th consecutive year of profitability. Southwest was the only major carrier in 1990, 1991, and 1992 to make both net and operating profits. It became a major airline in 1989 when it exceeded the billion-dollar revenue mark. It is the United States' only major shorthaul, low-fare, high-frequency, point-to-point carrier.