Airline employment up 1.6 percent

The largest "network," or legacy airline, employer was United Airlines. The Chicago-based carrier had 82,500 employees in May 2012, compared to 43,700 in May of last year before its merger with Continental Airlines was completed.

The largest low-fare airline employer was Southwest Airlines, which had 46,176 employees in May. The figure was an increase from Southwest's 35,882 employees in May 2011, before its own merger with AirTran Airways was completed.

The BTS said overall airline industry employment was down 5.9 percent from a peak in 2008 of 415,000 employees.