The US carrier Southwest Airlines reported a traffic improvement of 8.8% in September 2009, compared to the same month last year. Capacity was reduced by 7.8%, resulting in an increase of the load factor from 63.4% in 2008 to 74.7%. Southwest carried 5.8 billion RPMs (Revenue Passenger Miles - one RPM is defined as one passenger flown for one mile), while in 2008 they had been 5.3 billion. Capacity...