Acronyms, like looks, can be deceiving. Take the case of PSA Airlines, whose name links to its past, short-lived operations in the Pacific Southwest. The regional carrier, now a US Airways Group subsidiary and part of the US Airways Express network, serves about 150 eastern locations such as Charlotte, North Carolina; Dayton, Ohio; and Knoxville, Tennessee. It connects smaller markets with US Airways hubs like Charlotte and Philadelphia. PSA maintains a fleet of about 50 Canadair regional jets (CRGs) made by Bombardier. Overall, the US Airways Express carriers, including fellow subsidiary Piedmont Airlines and several independent lines, operate about 300 aircraft, comprising regional jets and turboprops.