Report No: DOT/FAA/AM-02/9

Title and Subtitle: Relationship of Employee Attitudes and Supervisor-Controller Ratio to En Route Operational Error Rates

Report Date: May 2002

Authors: Broach, D., Dollar, C.S.

Abstract: An operational error (OE) results when an air traffic control specialist (ATCS) fails to maintain appropriate separation between aircraft, obstacles, etc. Recent research on OEs has focused on situational and individual characteristics (Center for Naval Analyses Corporation, 1995; Della Rocco, 1999; Rodgers, Mogford, Mogford, 1998). In this study, the relationship of organizational factors to en route OE rates was investigated, based on an adaptation of the Human Factors Analysis and Classification System (HFACS; Shappell & Wiegmann, 2000) to air traffic control as HFACS-ATC (Scarborough & Pounds, 2001). OE rates (errors per 100,000 operations) for 1997 and 2000 were obtained from the National Airspace Incident Monitoring System (NAIMS) for 21 air route traffic control centers (ARTCC).

Organizational factors were represented by facility mean scores on scales constructed from 1997 and 2000 FAA Employee Attitude Survey (EAS) data. Factors included employee perceptions of equipment/facilities, performance management, overall job satisfaction, and perceptions of other human resources management practices. The supervisor-controller ratio (SCR) was calculated for each ARTCC by year from agency personnel data. SCR and organizational factors facility mean scores were regressed on OE rate (N=42). Two organizational factors and SCR accounted for 50% (adjusted R2 = .505, p < .001) of the variance in OE rates across ARTCCs for the two years. The standardized regression coefficients were -.290 for perceptions of equipment/facilities (t=-2.07, p < .05), -.302 for perceptions of performance management (t=-2.28, p < .05), and -.395 for SCR (t=-3.360, p < .01).

As expected from prior research, SCR was a significant predictor of en route OE rates. In addition, the results indicated that perceptions of how performance was managed and of facilities and equipment were also predictors of OE rates. Overall, the results support the inclusion of organizational factors as well as individual and situational characteristics in the investigation of ATCS operational errors.

Key Words: Air Traffic Controllers, Job Attitudes, Operational Errors, Human Factors, Performance, Psychology, Organizational Characteristics

No. of Pages: 13