I think that this is where it is coming from, copied from the us air web site, it is still on there if you want to see for yourself, its the PR when they announced the merger.
Fleet/Route System
US Airways/US Airways Express currently serves 179 cities and America West/America West Express serves 96 cities. When merged, the combined airline will become the nation’s fifth largest airline, as measured by domestic Available Seat Miles (ASMs). The combined airline is expected to operate a mainline fleet of 361 planes (supported by 239 regional jets and 57 turboprops for feed into the mainline system), down from a total of 419 mainline aircraft operated by both airlines at the beginning of 2005.
I think that PDT has 57 dashes.. doesnt say who is going to fly what, but people maybe reading through the lines.
BL