True, but look at the more important figure of total costs than CASM. The choice to use an RJ on a route needs to be dictated partially through traffic demand as well as costs. PHL-ATL should not be an RJ! There should be sufficient demand on this route to warrant mainline service. Many routes that have left the mainline, however (CLT-HSV) probably do not support mainline service under the current economics, even though the RJ CASM may be higher on this route, total costs vs. potential revenue just work out better with an RJ.BoeingBoy said:The RJ, while needed in some markets, has a higher CASM than mainline.