Where does US Air HUB?

As of my last knowledge update in October 2023, U.S. Airways, which merged with American Airlines in 2013, primarily operated hubs in several key cities, including Charlotte, Philadelphia, Phoenix, and Washington, D.C. Following the merger, these hubs became part of American Airlines' network. Therefore, the main hubs for the combined airline reflect American Airlines' operations rather than U.S. Airways specifically.