US Airways offices are in the Crystal City highrise office/appartment development which overlooks Washington National / DCA. That is in Arlington, Virginia, though the Alexandria city limits are at the southern border of the airport.
US is the largest carrier at DCA. They used to have a big presence at BWI, inherited when they took over Piedmont. Southwest has largely driven them out of BWI. US has a few flights from IAD.
DCA is not a US hub, but has a lot of connecting traffic from USAir Express. US Express is still mostly turboprop at DCA.
In the old Allegheny Airlines/Ed Colodny/ days, the airline's exectutive suite was in the NW corner of the northern hangar at DCA. It was said to be an example of VERY understated "luxury". Apparently that wasn't good enough for the new folks when it became US Air. US Air has even taken the historical plaque off the hangar entrance that went to the old offices.
Forgot to include this URL of a webcam on the top of a building close to US Airways headquarters. The camera is pointed in various directions during the day. [1 Feb - Sorry about the images, we have had poor visibility ever since I posted the URL. The cam points at DCA from time to time, especially at night.]
http://images.ibsys.com/dc/images/we...am_640x480.jpg