Where you can fly nonstop depends greatly on what aircraft are available. Especially internationally. Right now, US Airways uses three types of planes to fly to Europe: 293 or 258 seat Airbus A330s, 204-seat Boeing 767-200ERs and 176-seat Boeing 757s. Of those aircraft, only the A330s are here for the long run. US Airways wants to replace their existing 767s and 757 from 2017.
Only one problem though: there may be no real replacement 757 available. The 757 is a narrowbody aircraft and US Airways is concerned that the next generation of narrowbodies from Boeing and Airbus lack the range of the 757 and won’t be able to fly Philadelphia – Europe or even Phoenix – Hawaii routes. The airline currently also flies Charlotte – Dublin nonstop seasonally on the 757.
To put it another way, if a 258 seat aircraft is the smallest thing available for flights to Europe, it necessarily restricts the possible markets that can be served. That’s especially true from Charlotte, which in US Airways’ network gets the second flight the airline offers to a destination in Europe. (If US Airways and American Airlines merge, then CLT goes further down the priority list.)
So news that Boeing is studying a long-haul 757 replacement is a good sign. Not sure if it will amount to anything, of course, but it could potentially be worth several additional flights a day for US Airways to Europe.