The agreement, if approved, will bring the workers together for the first time since US Airways combined with America West in 2005. They've been working under separate contracts.
Details of the deal were not disclosed. The company and the thousands of in-flight crew had been negotiating with the help of a federal mediator.
The flight attendants are based in Phoenix, Philadelphia, Charlotte, N.C. and Washington D.C.
The Association of Flight Attendants Master Executive Counsel must approve the tentative agreement before it can be sent to its members for a vote. That's expected to happen in the next few weeks.
The tentative deal does not include US Airways Express flight attendants.
