Creating Safety in Air Traffic Control (review)

Creating Safety in Air Traffic Control. By Johan M. Sanne. Lund, Sweden: Arkiv, 1999. Pp. 333.

Air traffic control systems are under tremendous strain worldwide, a situation induced primarily by rapid growth in airline fleets. Many planners of future air traffic control systems believe that a major portion of the capacity problem derives from the "slowness" of pilot-controller radio communications, and thus that new systems must eliminate this problem through automation. Readers of Johan Sanne's fascinating study of how Swedish controllers work traffic will quickly perceive that this strategy is unlikely to succeed. Sanne convincingly argues that human-human communications, among controllers as well as between pilots and controllers, provide the system with its coordination functions, its reliability, and its flexibility through employment of that most old-fashioned medium: talk. The system's "wetware" (as humans are now called) are therefore the key to the construction of safety.

Sanne's book is the result of ethnographic research carried out in the mid-1990s at Stockholm Terminal Control and O¨stgöta KontrollCentral. Its central concept is William Sewell's formulation of "structuration," which Sanne uses to integrate the two existing approaches to complex systems, the "large technical systems" approach focused on organizations and the coordinative teamwork approach that emphasizes goal-oriented group interaction. Following Sewell, Sanne contends that because structures are enduring, they constrain individual and group action while providing resources to enable action, but that the structures themselves have to be maintained simultaneously by the actors. Taking this perspective allows Sanne to analyze how the structure of the system influences how the controllers work while also allowing an examination of how controllers' work sustains the system.

The core of the book is contained in two sections. In the first, "Organizing Traffic," Sanne seeks to link what he calls the "microlevel," controllers' daily work, with the "meso-level," the air traffic control system's organizational structure. In chapter 4, he explores the process of takeoff and landing from the controllers' viewpoint, emphasizing the division of labor among controllers and between controllers and pilots, how coordination is effected, and how controllers use "simulation" as a cognitive and coordinative tool. In the following chapter, Sanne considers the airspace structure, and how controllers utilize that structure, to argue that the airspace architecture is designed to reduce traffic complexity through the use of altitude and geographic segregation, allowing controllers to apply a normative scheme that aids teamwork, efficiency, and safety. Finally, he examines the process of estimating system capacity and allocating appropriate resources to argue that the process supports a particular division of labor that improves traffic organization while also producing system flexibility.

The second core section, "Creating Safety," includes the most interesting chapters in the book. Chapter 7 analyzes how controllers and pilots achieve "accurate and efficient talk," ensuring safe and efficient traffic organization, while also exploring how the same actors use talk to maintain the social fabric of the system. This is particularly important because pilots and controllers rarely meet. Instead, the vital social bonds of the system have to be maintained via "anonymous" radio links--in as few words as possible. Talk is also central to the succeeding chapter, which examines how it undergirds the achievement of a "common orientation" to the job and to specific situations. Technologies such as radar also foster a common orientation--for example, by eliminating of geographic markers from the radar screen while clearly marking sector boundaries and radio navigation aids.

Experience, a common language, and a common orientation, Sanne argues, provide controllers with a repertoire of solutions to various situations, hence experienced controllers do not tend to think in terms of rules or instructions when working traffic. He concludes the section with a review of the last fifteen years, to show how controllers have adapted their work processes and the airspace structure to cope with rapidly increasing traffic without substantially increased resources.

This is a good book, but it would have benefited from...