More than half of the U.S. air traffic controllers will retire within the decade as they meet the mandatory retirement age of 56. Most of today’s air traffic controllers were hired after President Ronald Reagan decertified and fired members of the Professional Air Traffic Controllers Organization (PATCO) during a strike twenty-years ago. The union that replaced PATCO, the National Air Traffic Controllers Association (NATCA), disagrees with the FAA on the number of controllers that will be needed by 2010 and the ability of the FAA to fill those positions.
See "Air Traffic Shortage on Radar: 7000 Controllers to Leave by 2010", Jon Hilkevitch, Chicago Tribune, August 12, 2001