Melissa M. Mallis

Fatigue Countermeasures in Aviation

Pilot fatigue is a significant problem in modern aviation operations, largely because of the unpredictable work hours, long duty periods, circadian disruptions, and insufficient sleep that are commonplace in both civilian and military flight operations. The full impact of fatigue is often underappreciated, but many of its deleterious effects have long been known. Compared to people who are well-rested, people who are sleep deprived think and move more slowly, make more mistakes, and have memory difficulties. These negative effects may and do lead to aviation errors and accidents. In the 1930s, flight time limitations, suggested layover durations, and aircrew sleep recommendations were developed in an attempt to mitigate aircrew fatigue. Unfortunately, there have been few changes to aircrew scheduling provisions and flight time limitations since the time they were first introduced, despite evidence that updates are needed. Although the scientific understanding of fatigue, sleep, shift work, and circadian physiology has advanced significantly over the past several decades, current regulations and industry practices have in large part failed to adequately incorporate the new knowledge. Thus, the problem of pilot fatigue has steadily increased along with fatigue-related concerns over air safety. Accident statistics, reports from pilots themselves, and operational flight studies all show that fatigue is a growing concern within aviation operations. This position paper reviews the relevant scientific literature, summarizes applicable U.S. civilian and military flight regulations, evaluates various in-flight and pre-/postflight fatigue countermeasures, and describes emerging technologies for detecting and countering fatigue. Following the discussion of each major issue, position statements address ways to deal with fatigue in specific contexts with the goal of using current scientific knowledge to update policy and provide tools and techniques for improving air safety.

Aircrew Fatigue, Sleep Need and Circadian Rhythmicity

Publisher Summary Fatigue cannot be eliminated from aviation operations because of the inherent schedule requirements for transmeridian travel, irregular and unpredictable schedules, long duty days, early report times, night flights, and reduced sleep opportunities. Many commercial aviation industry practices induce fatigue via sleep loss and circadian misalignment in flight crews. Therefore, there is a need to develop scientifically valid fatigue-management approaches to mitigate sleep loss, enhance alertness during extended duty periods and cope with circadian factors that are primary contributors to fatigue-related aviation incidents and accidents. This chapter begins by reviewing the homeostatic and the biological processes that regulate sleep, fatigue and alertness. Building on this foundational material, evidence is presented to demonstrate how sleep loss and circadian misalignment contribute greatly to fatigue and performance risks in short haul, long haul and ultra long range flight operations. The chapter concludes with a discussion of scheduling approaches, countermeasure application and fatigue management systems and technologies that can be used, in combination, as part of a comprehensive approach for ensuring that fatigue is effectively minimized in human centered aviation operations.

Data and methods for studying commercial motor vehicle driver fatigue, highway safety and long-term driver health

This article summarizes the recommendations on data and methodology issues for studying commercial motor vehicle driver fatigue of a National Academies of Sciences, Engineering, and Medicine study. A framework is provided that identifies the various factors affecting driver fatigue and relating driver fatigue to crash risk and long-term driver health. The relevant factors include characteristics of the driver, vehicle, carrier and environment. Limitations of existing data are considered and potential sources of additional data described. Statistical methods that can be used to improve understanding of the relevant relationships from observational data are also described. The recommendations for enhanced data collection and the use of modern statistical methods for causal inference have the potential to enhance our understanding of the relationship of fatigue to highway safety and to long-term driver health.

THE CARNEGIE MELLON TRUCK SIMULATOR: A TOOL TO IMPROVE DRIVING SAFETY

Carnegie Mellon Driving Research Center, together with ISIM, is presently involved in the design and development of an Advanced Human Factors Research and Driving Training Research Facility. This facility has been designed to address human factors issues and driver training issues. Human factors interests include developing countermeasures for fatigue and driver/vehicle interface issues. Driver training issues include validating the usefulness of simulators for driver training, developing effective curricula and investigating simulator fidelity needed for effective training. A key component of the facility is the Carnegie Mellon TruckSim that will be capable of simulating a variety of commercial and emergency vehicles using interchangeable cabs mounted to a common motion platform. TruckSims modular configuration will allow for rapid and cost effective design of experiments and training scenarios. A first research programme to evaluate fatigue countermeasures is presented as an example. (A) For the covering abstract of the conference see ITRD E203705.