Public Law 92-297, passed in 1971, requires that air traffic control specialists (ATCSs) hired after May 16, 1972 retire at age 56. The underlying rationale was that as controllers aged, the cumulative effects of stress, fatigue (from shift work), and age-related cognitive changes created a safety risk (U.S. House of Representatives, 1971). This hypothesis has been considered in two recent studies of en route operational errors (OEs). The Center for Naval Analyses (CNA, 1995) found no relationship between controller age and OEs. Broach (1999) reported that the probability of involvement in an OE increased with age. The purpose of this study was to re-examine the hypothesis that controller age, controlling for experience, was related to OEs. En route OE records (3,054) were matched with non-supervisory ATCS staffing records for the period FY1997-2003. Poisson regression was used to model OE count as a function of the explanatory variables age and experience using the SPSS® version 11.5 General Loglinear (GENLOG) procedure.