DALLAS, Feb. 4 /PRNewswire-FirstCall/ -- Southwest Airlines Co. (NYSE: LUV) announced today that the Company flew 5.1 billion revenue passenger miles (RPMs) in January 2009, a 6.4 percent decrease from the 5.5 billion RPMs flown in January 2008. Available seat miles (ASMs) decreased 4.4 percent to 8.2 billion from the January 2008 level of 8.5 billion. The load factor for the month was 62.8 percent, compared to 64.2 percent for the same period last year. For January 2009, passenger revenue per ASM is estimated to have increased in the six percent range compared to January 2008.