In 2007, the U.S. raised the mandatory retirement age to 65, from 60. That means that in late 2012 pilots who had stuck around for those extra five years began retiring, creating demand for new aviators to replace them.
In addition, pilots will require more time off between flights under new federal rules that take effect next year, which creates a need for more pilots.
Delta Air Lines Inc. has said it wants to hire 300 pilots starting in November. American Airlines has offered recalls to all of its furloughed pilots, though some have exercised an option to defer their return.
US Airways said last month that it would recall the last 66 furloughed America West pilots. Those two airlines merged in 2005. The pilots had been laid off in 2008.
United had already recalled 342 pilots, the pilots union said Thursday, and 600 more took jobs with Continental after those two airlines merged in 2010. The final steps in merging the two pilot groups happened this week, meaning the airline can generally retrain the returning pilots on planes that formerly belonged to either airline.
"Our furloughed pilots will be returning to a much better contract and to an airline with a brighter and more confident future," said Jay Heppner, a United captain and chairman of the Master Executive Council of its pilot union.
AP Airlines Writer David Koenig in Dallas contributed to this report.