Human Performance Modeling: Identification of Critical Variables for National Airspace Safety

Abstract

Computational human performance modeling tools have been under development for over 50 years to generate human performance predictions for studying complex human behaviors that possess high costs associated with failures. A common measure for analysis from the digital human modeling tools is operator workload. One complex behavioral environment that is being explored by international regulatory and airline operations groups and is likely to reflect workload differences is known as “free flight”. “Free flight” in the United States is a Federal Aviation Administration (FAA) strategic goal for system capacity and for Air Traffic Services to improve accessibility, flexibility, and predictability in the national airspace in order to reduce flight times, crew resources, maintenance, and fuel costs. The experimental scenarios used to explore “free flight” are based on the full “free flight” concepts anticipated by Requirements and Technical Concepts for Aviation (RTCA) in the year 2025. These concepts explore the farthest out parameters of the aviation system. An evaluation of predicted behavioral costs associated with current day and “free flight” operations was performed using two “first principles” models, Air Man-machine Integration Design and Analysis System (Air MIDAS) and the Integrated Performance Modeling Environment (IPME). In analyses of a common scenario, both tools revealed increases along a seven-point, four-channel workload scale from current (M _{Air MIDAS} = 0.77, M _IPME = 1.24) to “free flight” operations (M _{Air MIDAS} = 1.15, M _IPME= 1.96). The inclusion of a handoff and an emergency event was found to increase the workload levels of the virtual operators within both software tools and provided different performance profile predictions depending on the operator's role in the NAS when faced with such a rule set change as the one proposed by the RTCA (Air MIDAS current day - M _ground = 0.84, M _Air = 0.71; IPME current day - M _ground = 1.85, M _Air = 0.62; Air MIDAS “free flight” - M _ground = 0.77, M _Air = 1.53; IPME “free flight” - M _ground = 2.07, M _Air = 1.84). These findings support the notion of initially using models for exploration of variables for inclusion in costly simulation studies. A validation effort of these findings with human-in-the-loop data is required and anticipated.