Also, Vahidi noted that since 2006, US Airways has operated at a 15% RASM deficit to American. But US Airways spokeswoman Michelle Mohr said Wednesday: "It's well-known that we have a revenue disadvantage of about 16% against our peer network carriers largely due to the location of our hubs and nature of our routes, (but) it is also well-known that we maintain a 19% cost structure advantage against the network carriers to help offset this revenue disadvantage." As for American's fleet modernization plan, it is not going to happen immediately. In fact, the carrier will not begin work on the project until early 2014, about two years from now, and it is not known when the work will conclude. Rob Friedman, vice president of marketing, told reporters that "aircraft retrofits require a tremendous amount of lead time." Nevertheless, he said, It was important to announce the project Wednesday in order to send "a very important message to our customers and people that we are investing in products and services to provide a world class experience." -- Written by Ted Reed in Dallas/Fort Worth International Airport. >To contact the writer of this article, click here: Ted Reed >To follow the writer on Twitter, go to http://twitter.com/tedreednc.