Air traffic controller staffing affects safety. This chapter examines the aviation safety record in the United States, the role that accidents related to air traffic control (ATC) play in that record, and how aviation safety data might be analyzed to shed light on the relationships between air traffic controller staffing and aviation safety. A discussion of the Federal Aviation Administration’s (FAA’s) Federal Contract Tower Program follows, along with an evaluation of safety comparisons between low-activity FAA towers and contract towers. The chapter describes known best practices in scheduling to address concerns with regard to fatigue as identified in the United States and by other air navigation service providers (ANSPs) and the International Civil Aviation Organization (ICAO). Implementing such practices could require adjustments in how a controller staffing plan is executed and perhaps in staffing levels. Finally, the chapter addresses concerns in establishing and maintaining a “safety culture” in which staffing levels must be sufficient for managing traffic and for enabling proper reporting and controller involvement in safety management and in which the appropriate data are collected and used in the planning and implementation of controller staffing.
This section places ATC-related accidents1 in the context of all aviation accidents.2 It then considers how accident and incident data might be analyzed to help in understanding relationships between air traffic controller staffing and aviation safety.
Table 2-1 shows the total number of aviation accidents and the total number of ATC-related accidents from all causes in the United States between 1990 and 2012, by industry segment. Fatal accidents accounted for 20 percent of the more than 41,000 total accidents during the period. Air carriers accounted for less than 1 percent of fatal accidents, although these accidents corresponded to slightly more than 10 percent of aviation fatalities, which is likely due to the larger number of passengers per airplane associated with air carrier operations. Air taxis and commuters were responsible for approximately 5 percent of fatal accidents and for 8 percent of fatalities, and general aviation (GA) accounted for 94 percent of fatal accidents and for 82 percent of fatalities.
ATC was considered as either a cause or a factor by the National Transportation Safety Board (NTSB)3 in 66 fatal accidents, which corresponded to 249 fatalities over the 1990–2012 period—about 0.8 percent of all fatal accidents and 1.4 percent of all fatalities. ATC is
1The committee considered ATC-related accidents to be those in which accident investigation by the National Transportation Safety Board found that air traffic control was either a “cause” or a “factor” in the accident.
3For purposes of the committee’s analysis, no attempt was made to distinguish the degree of involvement of ATC errors, including omissions, in the fatal accidents. Thus, the two NTSB categories, causes and factors, were combined.