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Summary The airline industry operates 24 hours a day, 7 days a week, deliver- ing passengers and cargo to locations worldwide. The pilots who fly the airplanes rely on their own expertise and judgment, that of their fellow crew members, the safety features of the airplane, and characteristics of the aviation system to ensure that the flights arrive safely. Fatigue is a widely ac- knowledged potential safety risk factor that can contribute to less effective pilot performance. Although the number and timing of hours worked and hours slept can contribute to fatigue, the federal regulations that govern pilot flight and duty time have not been revised in decades. In summer 2010 the U.S. Congress directed the Federal Aviation Ad- ministration (FAA) to update these regulations, taking into account recent research related to sleep and fatigue. A Notice of Proposed Rulemaking (NPRM) was released September 14, 2010. As part of their directive, Congress also instructed FAA to have the National Academy of Sciences conduct a study on the effects of commuting on pilot fatigue. The study was designed to review research and other information related to the prevalence and characteristics of commuting; to the science of sleep, fatigue, and circa- dian rhythms; to airline and regulatory oversight policies; and to pilot and airline practices.1 It was intended to inform the commuting-specific compo- nent of the final regulations. This report describes the results of that study. Pilots live in diverse geographic regions. They commute between where they live and the airports where their duty assignment begins (i.e., their 1 This study was restricted to airlines operating under 14 CFR 121, which includes most passenger and cargo airlines that fly transport-category aircraft with 10 or more seats. 1
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2 THE EFFECTS OF COMMUTING ON PILOT FATIGUE domicile). The committee considers pilot “commuting” to be the period of time and the activity required of pilots from leaving home to arriving at the domicile (airport—in the crew room, dispatch room, or designated location at the airport) and from leaving the domicile to returning back to home. Pilot commuting takes place during off-duty hours. Pilot commuting differs from the commuting of other workers in terms of frequency and variability, distance, transport modes, and time of day. Most pilots work for four main types of airlines: mainline airlines that predominately operate scheduled service in jet aircraft with more than 90 seats and often provide intercontinental service; regional airlines that pre- dominately operate scheduled service in aircraft, both jet and turboprop, with 90 or fewer seats; cargo airlines that deliver goods all over the world; and charter airlines that provide nonscheduled passenger flights. Flight scheduling, commuting provisions, seniority systems, and length of duty time vary across these segments of the industry. For most airline pilots, decisions about where to live and when and how to commute are their own to make. Generally, given the nature of flight scheduling, pilots do not commute on a daily basis; in fact, in some cases, they commute only two or three times a month. However, there are no comprehensive data on the frequency of pilot commuting, the lengths of commutes, or such trip characteristics as the transportation modes used in commuting. There are also no systematic data on the timing, duration, or quality of pilots’ sleep before or during their commutes. Furthermore, changes in airports to which the pilots’ report for the start of their duty (their domicile) may alter commuting patterns, but the committee was un- able to obtain any systematic information about how frequently individual pilots experience domicile changes or how such changes affect pilot com- muting behavior. The committee’s analysis of home-to-domicile distances, calculated from zip codes of 17,519 mainline pilots and 7,553 regional airline pilots, provided by 15 airlines, showed that roughly one-half have home-to- domicile distances of less than 150 miles. Less than one-fourth have home- to-domicile distances of more than 750 miles. The distributions are similar for mainline and regional pilots even though these two segments of the industry differ. The proportion of pilots who have long coast-to-coast or international home-to-domicile distances is about 2 percent for mainline pilots and 1 percent for regional pilots. The committee also analyzed the home-to-domicile distances of 4,488 airline pilots from four cargo air- lines and 631 airline pilots from five charter airlines, but many of those airlines have different basing policies so the data from their pilots are not directly comparable to mainline and regional airlines. These home-to-domicile distances are only suggestive of commuting patterns for several reasons. First, the pilots’ residence zip codes were for
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3 SUMMARY their homes of record (i.e., those designated by the pilots on IRS forms and for the receipt of official notices from the airlines). Some pilots may have more than one home, and some may commute to work from temporary or seasonal residences that are not frequent origination points for their com- mutes. Second, pilots may arrange for rest facilities and obtain sleep at or near their domiciles (or at an en route location for a multistop commute) between leaving home and arriving at the domicile. Third, commutes may have varying degrees of circuity, particularly those involving multiple con- necting flights, so that the actual distances traveled are likely to be longer and may be much longer than the straight-line distances. Fourth, these data are for one point in time and provide no insight into how commut- ing patterns might change in response to a pilot’s career progression or from changes in the patterns of airline operations that result from mergers, bankruptcies, and changing economic or competitive conditions. Finally, the committee does not know the extent to which the sample of pilots in this analysis is representative of the larger pilot population. We caution the reader not to assume that the distance pilots live from the airport reflects their likely commute times. There is remarkably little data to evaluate this assumption. In all four segments of the industry, a breakdown of the home-to- domicile distances by airline suggests that there is considerable variation across individual airlines. Similarly, an analysis of changes in aircraft de- partures from the principal cities served by each of 30 mainline, regional, and cargo airlines also found large differences in changes in flight patterns across airlines. Overall, the airline industry is heterogeneous, with great variability across the entire industry, in each segment of the industry, and for individual airlines, as well as among individual pilots. Commuting is one of many activities that usually take place during a pilot’s off-duty time. If decisions about how and when to commute result in a pilot’s not having adequate sleep, or if unanticipated circumstances prevent adequate sleep, there is the clear potential that the pilot will arrive to work fatigued and be forced to make the decision about being fit to fly. Similarly, if sleep is inadequate as a result of commuting time and the pilot does not decline the flight assignment on grounds of fatigue, the pilot may experience fatigue during the flight and duty period. A pilot’s decision about fitness for duty is likely made within the context of the flight schedule, the airline’s relevant policies and their implications for pay (i.e., whether or not the pilot will get paid if he or she calls in fatigued or sick), and knowledge about the specifics of the airplane and flight. Most jet airplanes are highly automated, with the periods of greatest pilot activity for most flights occurring during takeoff and landing. Most turboprop regional airplanes are less automated. There have been few aviation accidents in which fatigue was cited as a probable cause or contributing factor by the National Transportation Safety
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4 THE EFFECTS OF COMMUTING ON PILOT FATIGUE Board (NTSB), the agency responsible for investigating all U.S. airline (and other transportation) accidents.2 Of the NTSB reports for the 863 relevant accidents that occurred between 1982 and 2010, only nine of the accidents for which the investigation was complete mentioned fatigue as a prob- able cause or contributing factor.3 None mentioned commuting as either a probable cause or contributing factor. However, it can be difficult during an accident investigation to determine the extent to which fatigue might have played a role in the accident as well as the extent to which commuting might have contributed to fatigue. Based on the available information on (1) the commuting practices of pilots and commuting policies of airlines, (2) aviation accident reports, (3) the range of distances pilots live from their work domiciles, and (4) sci- entific information on fatigue that results from inadequate sleep, prolonged time awake and circadian timing, the committee concludes the following. CONCLUSION: There is potential for pilots to become fatigued from commuting. However, there is insufficient evidence to determine the extent to which pilot commuting has been a safety risk in part because little is known about specific pilot commuting practices and in part because the safety checks, balances, and redundancies in the aviation system may mitigate the consequences of pilot fatigue. Given that there is some potential for commuting to contribute to fa- tigue and clear evidence that fatigue can decrease performance, the commit- tee believes it is important to reduce the likelihood that commuting could contribute to pilot fatigue during duty. At the same time, the safety risk posed by commuting-induced fatigue is unknown. There is a need to un- derstand the extent to which the risk posed by fatigue resulting from some commutes may be mitigated by individual, airplane (e.g., flight deck sys- tems), or aviation system (e.g., crew resource management) characteristics. Furthermore, there is tremendous variability across individual pilot commuting practices and day-to-day experiences. Attempting to determine 2 An aircraft accident is defined in Title 49 Section 830.2 as “an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage” (Code of Federal Regulations, 2009). 3 “The NTSB determines the probable cause or causes of accidents. The objective of this determination is to discern the cause-and-effect relationships in the accident sequence. This could be described as why the accident happened. In determining probable cause, the NTSB considers all facts, conditions, and circumstances associated with the accident. Within each accident occurrence, any information that helps explain why that event happened is designated as either a ‘cause’ or ‘factor.’ The term ‘factor’ is used to describe situations or circumstances that contribute to the accident cause” (National Transportation Safety Board, 2010a, p. 52).
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5 SUMMARY a one-size-fits-all delineation on what constitutes a fatiguing commute based on either time or distance is difficult because the length of the com- mute, measured either by distance or time spent commuting, does not necessarily determine whether or not the pilot reports fit for duty and well rested. In addition, regulations specific to commuting could inadvertently lead to increased safety problems and additional loss of lives due to the unintended and unanticipated consequences. Consequently, although action is warranted to reduce the likelihood that commuting will present a safety risk, there is a lack of evidence to support the basis for issuance of regula- tions pertaining to commuting. CONCLUSION: There are inadequate data to specify or determine the effectiveness of regulations regarding pilot commuting. Additional information is needed to determine if a regulatory approach ultimately would be appropriate. At the same time, there is extensive scientific evidence on the nega- tive effects of fatigue on performance of many cognitive tasks, including those essential for safely operating a commercial aircraft. These include adverse effects of fatigue induced by sleep loss on maintaining wakefulness and alertness, vigilance and selective attention, psychomotor and cognitive speed, accuracy of performing a wide range of cognitive tasks, working and executive memory, and on higher cognitive functions such as decision making, detection of safety threats, and problem solving, as well as com- munication and mood. Fatigue is not, however, a binary condition in which one is either rested with no negative effects on performance or fatigued with severe negative effects on performance. There are degrees of fatigue and degrees of the negative effects of fatigue on performance. Moreover, the effects of fatigue on performance can vary substantially from one pilot to the next without any untoward effects on the safety of flight. The scientific literature shows fatigue as a risk to performance that can result from (1) being awake continuously for more than approximately 16 hours, or (2) sleeping too little (especially less than 6 hours on the day prior to work), or (3) when undertaking work at a time when the body is bio- logically programmed to be asleep (i.e., an individual’s habitual nocturnal sleep period), which for most people is between 10:00 p.m. and 7:00 a.m. Evidence that cognitive performance is adversely affected when sleep per 24 hours is cumulatively less than approximately 6 hours of sleep suggests that pilots should seek to obtain sufficient bed time to ensure they are fit for duty. The detrimental effects of fatigue on performance may be exacerbated by a tendency for individuals to have reduced awareness of the cognitive performance deficits that result. Pilots are currently required to report fit for duty. Judging whether a
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6 THE EFFECTS OF COMMUTING ON PILOT FATIGUE pilot is fit for duty is an individual pilot decision that should take into ac- count the amount of sleep received prior to duty. RECOMMENDATION 1: Pilots should avoid planning commutes or other preduty activities that result in being awake beyond approxi- mately 16 hours before the scheduled end of duty, endeavor to sleep at least 6 hours4 prior to reporting for duty, and obtain more than 6 hours sleep per day whenever possible to prevent cumulative fatigue from chronic sleep restriction. Pilots should also consider the amount of sleep and time awake in their decision making relative to when to inform their supervisors that they should not fly due to fatigue. Although there are currently no agreed-on objective standards in the aviation industry to determine whether a pilot is reporting to duty fatigued, there are provisions in the proposed NPRM—Section 117.5—for assess- ment by others of whether a pilot is fatigued. The validity and reliability of such assessments are unknown, as is the likelihood that they can result in either false positives or false negatives. Consequently it is uncertain whether they can result in effective prevention of fatigue. CONCLUSION: With regard to the proposed provisions in Section 117.5, there are no valid and reliable tools and techniques feasible to reach the goals of detecting fatigue and fitness for duty in pilots in an operational setting. To achieve these goals, further research would be needed to scientifically validate the tools and techniques, demonstrate that they are technically feasible in an operational environment, and evaluate their relationship to operational safety and the extent to which they can be integrated into an operational context. Potential fatigue is an inherent component of a system that functions 24 hours a day, 7 days a week. Recognizing this, the international aviation industry has been developing an approach through fatigue risk management systems (FRMS) to better understand when fatigue is a concern and how to best mitigate that risk. Airlines develop FRMS specific to their operational environment. To date, commuting has not been a major consideration in these systems. Incorporating data on commuting in relation to pilots’ duty hours and sleep prior to duty would help inform these systems and allow airlines to consider mitigation strategies specific to their operations. 4 This refers to at least 6 hours of physiological sleep. Since physiological sleep is typically 85 to 95 percent of total bed time in healthy adults, time in bed for sleep will have to be 6.5 to 7 hours to ensure at least 6 hours of physiological sleep are acquired.
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7 SUMMARY RECOMMENDATION 2: The potential effects of commuting on pilot fatigue should be addressed as part of an airline’s strategies to man- age fatigue risk. If airlines develop fatigue risk management systems (FRMSs), they should gather information about preduty sleep and wake time relative to commuting practices and duty cycle. FRMSs should provide a mechanism for identifying problematic patterns and addressing them. FRMSs can offer both the airline and the Federal Aviation Administration an improved assessment of crew alertness dur- ing normal operations and thereby provide some information on the contribution of commuting to fatigue and whether fatigue is or is not within an acceptable level of risk. Fatigue risk management plans (FRMPs) are the airline carriers’ man- agement plans outlining policies and procedures reducing the risk of flight crew member fatigue and improving flight crew member alertness. Public Law 111-216 requires each U.S. carrier operating under Part 121 (most passenger and cargo airlines that fly transport-category aircraft with 10 or more seats) to submit to the FAA their draft FRMPs for review and ac- ceptance. Provided in the FAA’s guidance on the development of an FRMP is a requirement for a fatigue education and awareness training program element, one of the subtasks of this element is the effects of commuting on fatigue. This requirement reflects the perspective that managing the effects of commuting on fatigue is a joint responsibility of airlines and pilots, a posi- tion with which the committee agrees. Although the FRMP approach is not as rigorous as the FRMS process, it is required of all Part 121 airlines and therefore presents an opportunity to reach a wider audience than FRMSs. RECOMMENDATION 3: The committee supports fatigue education and awareness training as part of an airline’s fatigue risk manage- ment plan. Training relative to commuting should include guidelines regarding the effects of inadequate or disturbed sleep or prolonged wakefulness on fatigue and performance. Fatigue education and aware- ness training should be annually updated with particular attention to incorporating relevant new developments in sleep science. As part of its data collection, the committee requested that airlines submit information on their pilot commuting, sick leave, and fatigue poli- cies, if available. Although only a small proportion of airlines responded (39 percent), it is clear from the information submitted and from comments provided in public that there is considerable diversity in these policies. In addition, not all airlines have commuting or fatigue policies, with pilots relying instead on sick leave availability to address potential fatigue. Air-
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8 THE EFFECTS OF COMMUTING ON PILOT FATIGUE lines should consider policies that would help pilots plan predictable com- mutes that do not promote fatigue on duty and policies that minimize the negative consequences when unanticipated events alter their commuting plans and lead to fatigue. The effects of these policies on pilot behavior are currently not well understood. RECOMMENDATION 4: The Federal Aviation Administration should convene a joint industry, labor, and government working group, un- der the auspices of an independent organization (such as the Flight Safety Foundation), to assess industry policies on pilot commuting, sick leave, attendance/reliability, and fatigue and to develop industry best practices. The output of this joint working group should inform the development and updating of airline’s fatigue risk management plans and should be validated periodically. Pilots make decisions about commuting in the context of other factors in their lives, the specifics of their flights, the policies in place at their air- lines, including sick leave and commuting policies, and other environmental factors. It is unclear to what extent pilots are aware of the findings from current decision science or consider this information in their decision mak- ing. Decision-making strategies informed by this science could be incorpo- rated into FRMP training and considered in the development of industry best practices. RECOMMENDATION 5: The Federal Aviation Administration should commission efforts to develop protocols and materials for training pi- lots to make decisions regarding commuting easily and effectively and to ensure that they are informed by current decision science. As noted above, little is known about pilots’ commuting patterns and the extent to which their commuting patterns may affect the amount or quality of sleep or the amount of time awake prior to duty. A better un- derstanding of the relationship of commuting to primary risk factors for fatigue would represent a first step in increasing understanding of the relationship between commuting and fatigue. This information, combined with information that is recommended for inclusion in fatigue risk manage- ment plans, or in fatigue risk management systems when such systems are required, will provide input needed to inform further research and industry policies. RECOMMENDATION 6: To inform the development of industry best practices and policies relative to commuting, the Federal Aviation Administration should fund a study to determine the relationships
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9 SUMMARY between distance from domicile and five primary fatigue risk factors: (1) sleep quantity in the 48 hours prior to the end of duty on each day of the trip; (2) sleep quality in the 48 hours prior to the end of duty on each day of the trip; (3) time awake in the 48 hours prior to the end of duty on each day of the trip; (4) cumulative sleep time in the 72 hours prior to the end of a duty period; and (5) circadian phase at which sleep is obtained and at which duty is undertaken. In order to be maximally useful, the study should include a large random sample of pilots from multiple companies representing the major industry segments. The study should provide objective data on fatigue risk antecedents by us- ing a well-validated technology that provides reliable information on sleep and wake periods, such as wrist actigraphy, as well as sleep-wake diaries. Collecting data on a 48- to 72-hour period is needed to fully under- stand pilots’ commuting experiences in the context of the many factors that affect their lives and work. The results of the study can help to identify situations that may warrant specific attention or additional research.
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