By Jim Glab (http://executivetravelmagazine.com/...ers?xid=TLCHECKIN122611BloombergAnalysisRates) How do you calculate which airlines provide the greatest level of ‘hassles’ for passengers, and which offer the least? Bloomberg Analysis, an affiliate of Bloomberg News, has issued a ranking of U.S. airlines based on the quality of the passenger experience. Bloomberg studied the 10 largest U.S. airlines based on an index that combined the kinds and levels of fees charged by the carriers along with their operational performance – i.e., number of delayed and canceled flights. The percentage of seats filled also figured into the analysis, on the assumption that the more crowded a plane is, the more of a hassle it is for all passengers. On a 100-point scale, Bloomberg concluded that the lowest hassle factor was for passengers of Southwest, which scored 73.2. At the other end of the list was American Airlines, with a dismal 31.2 score. No regional affiliates were included in the analysis. But American had plenty of company on the lower end of the rankings. US Airways had a score of 32.5, while United got a 33.6 and Continental 35.7. United and Continental were scored separately because they are still operating as separately branded airlines. Other low-cost carriers fared well in the analysis. Ranked second behind Southwest was Frontier Airlines with a score of 61.6, followed by Alaska (56.3). In the middle of the pack were AirTran Airways (a subsidiary of Southwest) at 45.1; Delta, the highest-ranking legacy carrier, at 44.3; and JetBlue at 38.1.