Automation is often implemented in an attempt to reduce the operator's workload during peak periods of task load. This article reports on a study that focused on two aspects of air traffic controller-automation interactions: whether automation can reduce controller workload and how automation reliability affects controller performance and workload. The study was prompted by recent recommendations that would result in pilots having greater freedom to choose their own heading, altitude, and speed in real time and primary responsibility for maintaining separation from other aircraft in the immediate airspace. Controllers would manage traffic flow, leaving the detection and resolution of conflicts to the pilots, and intervening only if aircraft separation falls below a certain value. The experiments examined the effects of an aircraft-to-aircraft conflict decision aid on the performance and mental workload of experienced, full-performance level controllers in a simulated Free Flight environment. Performance was examined with both reliable (Experiment 1) and inaccurate automation (Experiment 2). Results showed that the aid improved controller performance and reduced mental workload when it functioned reliably. However, detection of a particular conflict was better under manual conditions than under automated conditions when the automation was imperfect. The authors conclude by discussing the implications of these findings for design engineers who are creating the automation aids.
Abstract