Preventing Vehicle-Aircraft Incidents During Winter Operations and Periods of Low Visibility (2008)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

23 Human factors involves gathering information about human abilities, limitations, and other characteristics, and applying it to tools, machines, systems, tasks, jobs, and environments to produce safe, comfortable, and effective human use (9). In avi- ation, human factors is dedicated to better understanding how humans can more safely and efficiently be integrated with the technology. That understanding is then translated into design, training, policies, or procedures to help humans perform better. One of the primary human performance factor topics mentioned in the survey and associated with increasing the possibility of error and risk during snow removal operations was the issue of fatigue. FATIGUE Fatigue is widely recognized as a core safety issue in the air transportation industry. It is on the NTSB’s list of most-wanted safety improvements in aviation (2). And while the NTSB avi- ation recommendations are directed more toward pilots and mechanics, the recognition of fatigue in other safety-related areas of aviation are of no less importance or impact. This is evidenced by the number of times respondents mentioned fatigue in the survey and in the examples they provided. Fatigue refers to one’s inability to maintain sufficient alertness in a job. In general, fatigue results from inadequate rest over a period of time, which leads to the physical and men- tal impairment of an individual. The literature search revealed that numerous studies on fatigue have been conducted in the aviation field, but the overwhelming majority has been directed toward flight crew members and aircraft maintenance employ- ees. Fatigue has not been readily studied within airport oper- ations and, in particular, snow removal operations. And while the air transport industry has been required by the FAA and ICAO to establish fatigue management practices in their oper- ations, those working on the airfield have not been subject to such regulation. Snow removal crews, in particular, are vulnerable to the effects of fatigue due to the long hours of operation, the nature of the environment the operators work in, and the time of day during which many snow events occur. An example of the long hours is illustrated in one non-hub airport’s snow plan: The airport will have a maintenance crew and an Operations Supervisor on duty during winter months (November 1st through April 1st) from 4:00 a.m. until the arrival of the last air carrier flight each day. If needed, personnel shall work through the night to continue snow removal operations as warranted. The FAA has recognized the impact of fatigue on airfield operations and has mentioned it in AC 150/5210-20, Ground Vehicle Operations on Airports (3) and AC 150/5200-30, Airport Winter Safety and Operations (12) as a collision risk factor to be considered by airport management in their operational plans. An individual engaged in winter operations can experience one of two types of fatigue: acute or chronic. Acute is short term and is experienced as a direct consequence of some activity, such as strenuous exercise or intense mental concen- tration, which often occurs during winter storm operations. Acute fatigue would be experienced during and after a typical winter storm requiring the operator to engage in winter oper- ations for one day. Chronic fatigue (a.k.a, cumulative fatigue) is a cumulative state of tiredness and decreased alertness, and is directly related to the physiological need for sleep. Chronic fatigue is more severe and longer-term than acute fatigue. Chronic fatigue develops when an individual camps out at the airport and works continuously over the length of a major storm for several days without adequate rest or recovery. The risk of an error or mistake increases with the degree of fatigue experienced. Recognizing when one is fatigued and taking action to counter it are two important components of a safe operating system. Research has determined that vehicle operators are aware they are fatigued, in part because they actively fight sleep by opening the vehicle window, turning up the radio, fre- quently moving around in the seat, drinking coffee, etc. (37). Recognizing symptoms of fatigue then becomes an SA issue that all vehicle operators and airport organizations need to address in their training and operations. FATIGUE AS AN ISSUE At its core, fatigue is caused by a lack of restorative sleep. The evidence from various studies suggests that there are three broad factors that can contribute to a lack of restorative sleep: (1) the time of day work takes place, (2) the length of time spent at work and in work-related duties (such as driving to and from work), and (3) the amount and quality of rest obtained prior to and after a work period (37). CHAPTER FIVE HUMAN PERFORMANCE

Typically, combinations of these factors contribute to the risk of fatigue. For example, a person operating a vehicle at night, after extended hours on the job and with a lack of qual- ity sleep prior to work, would be facing a significantly higher operational or accident risk than someone exposed to only one of the fatigue factors. Merely limiting the hours of work through regulation or by directive does not adequately address the problem of fatigue. Factors such as time of day, the amount of prior rest, and the timing of rest breaks are central to managing fatigue. The National Road Transport Commission of Australia has developed a Fatigue Management Scheme module that, although focusing on truck and heavy vehicle operators, has implications for airport snow removal operators as well (38). To qualify for the Fatigue Management Scheme certification, operators and drivers must identify and manage fatigue risk factors such as trip scheduling, driver availability, time work- ing, lifestyle, quality of rest, and driver health standards. A key feature of the Australian regulations is the inclusion of a “chain of responsibility” provision. This refers to the notion that airport organizations, from front-line supervisors to executive management, have responsibility for preventing incidents and accidents by implementing fatigue-related countermeasures. This is very similar to current FAA efforts to implement SMS at airports. The organization has as much responsibility as does the individual employee, if not more so, for alleviating fatigue and stress factors among its employees. In reviewing the snow plans of the airports, it became apparent that such fatigue countermeasures were not part of an airport operator’s SICP or training regime, nor were they even mentioned. A review of separate policy and procedure manuals for several airports did mention fatigue, but they did not go into detail as to how to mitigate it. There was no guidance given for shift duty time, adequate rest time, off- duty-related activities, physiological health factors, or other similar causes of fatigue. FATIGUE FACTORS AND CAUSES When asked to list the factors that they had experienced or thought contributed to driver fatigue or impairment, survey respondents identified factors that could be grouped into the following general areas: long work hours without breaks, irreg- ular time, stress, boredom, environmental conditions, vehicle design and ergonomics, personal health, and staffing. Long work hours with no breaks was the main factor that many of the respondents to the questionnaire said contributed to the buildup of fatigue, or which resulted in driver impair- ment. Unfortunately, working double shifts seems to be the norm in the industry in light of the unpredictability of when snow events occur and the need to finish the job before anyone 24 can go home. This has implications associated with staffing levels. Surprisingly, staffing levels were not cited as a prominent factor by respondents, but certainly staffing levels have a lot to do with “seat time.” There seems to be an acceptance within airport organizations that staffing levels are set and employees are expected to get the job done no matter how long it takes. Long hours without breaks were commonly cited, more so at smaller airports than larger ones. Larger airports appear to be able to rotate individuals, thereby being able to give breaks. And even if given a break, several respondents noted how difficult it was to actually rest, in part because of the nature of the operation (need to stay on top of the snow event or to get the airport open), the individual being “wired” from too much stimulant (caffeine, high activity, etc.), or no place to rest (breaks taken out on the field, in the cold, or in the vehicle). Contributing to the fatigue experienced while at an airport, several respondents cited how one spends their time before the snow event as a major factor affecting their abilities. Many respondents recognized the need for rest beforehand but cited the irregular and unpredictable timing of a snow event as impacting their need for rest. For instance, if they had little rest in the days prior to a snow event, or if they get a call while sleeping, or if having been sent home early to rest for the pre- dicted snow event only to not be able to rest because it was out of sync with their circadian rhythm, the sleep disruption combined with stress creates additional burdens affecting their performance and decision making. Although long working hours was the primary factor cited, one respondent noted that long working hours might not be so bad if the task of snow removal wasn’t so boring at times. Idle sitting time waiting for an aircraft operation to be completed prods the body to rest. From that rest the body must be jolted into action when time comes to resume operations. One respondent noted how different the transition was from high- way plowing to airport plowing. On the highway, the vari- ability and obstacles kept him attuned and concentrating on the task. At the airport, the monotony and repetition of going up and down the runway made it easy to become complacent. Fatigue can impair a driver’s decision making and perfor- mance. So can stress—a factor that often contributes to mental and physical fatigue. Stress emanates from the need to keep the runway open, to not cause harm or damage, to get things done quickly, to satisfy other’s demands (bosses, airlines, ten- ants, landside operations), and by aircraft wanting to operate on the movement areas. But according to the survey respon- dents, those are not the only sources of stress. They also cited home life, job satisfaction, and the drive to work itself (the need to get to work in worsening snow conditions) as factors. Stress, of course, affects a person’s performance. A little stress is beneficial in maintaining alertness. Too much stress, however, and a person becomes overwhelmed, ineffective,

25 and starts to make errors. Stress is the body’s reaction to a change that requires a physical, mental, or emotional adjust- ment or response. To better manage stress, research indicates that one must take care of the physical, mental, and emotional components of stress (38). Factors such as age, proper nutri- tion, and taking medications were mentioned by respondents to the questionnaire as having an affect on one’s ability to manage stress. Several individuals made note of the eyestrain caused by blowing snow and bright lights as a major factor contributing to fatigue. Blowing snow and brighter than normal lights constitute part of the operating environment the drivers encountered during winter operations. Because snow plows can operate at speeds up to 40 mph during snow removal, the need to see as far forward as possible requires lights that will illuminate as far as possible, which means more powerful and brighter lights than normal vehicle headlamps. Together, the bright vehicle lights and runway lights set at high settings contribute to driver fatigue. Vehicle engine and wind noise, climate control fans blowing, and the chatter of various aviation radio frequencies, all contribute to environmental factors causing fatigue. When one adds the alternating cold and heat of the outside and inside cabin environments into the situation, one can understand why those factors were cited by respondents as contributing to fatigue and driver impairment. Snow equipment manufacturers have only recently attempted to address in their vehicle designs some of the environmental factors stated earlier, as well as some of the ergonomic factors that have plagued drivers in the past. Quite a few respondents mentioned vehicle design parameters as impacting their performance. It was clear by the survey response that some airports are still using old equipment, in that respondents cited the following as affecting their abil- ities: controls were not laid out well, the seats were uncom- fortable, the condition of the cabin was old and worn, there wasn’t room to move around in the cab, some vehicles still had manual transmissions requiring constant shifting, and the vehicles experienced frequent breakdowns. Vehicle design parameters are discussed in greater detail in chapter eight. FATIGUE MITIGATION AND MANAGEMENT Given that there are many different factors causing fatigue, they can be grouped into common attributes, as can the responses for mitigating or managing them. The groupings are best described as the following: limit duty time, provide sleep or rest facilities, provide food and drink, provide frequent or adequate breaks, rotate assignments, consider ergonomic factors, and other. Limit Duty Time Limiting duty time was the most frequently mentioned sug- gestion for mitigating fatigue. The length of duty time varied among airports. A maximum of 12 h of duty time was men- tioned by several respondents. General aviation and non-hub airports, where the norm is to have but one daily shift of maintenance operations, would be most likely to utilize that length of time. Beyond 12 h of duty time, fatigue becomes a factor for professional drivers (24). At larger airports, where multiple shifts are staffed, the suggestions were to limit the employees to one normal shift or to no more than 10 h, and/or to stagger the staffing over several shifts. Several airports cited policies of 4 to 6 h on and 4 to 6 h off. Sending one shift home early in anticipation of a later recall is practiced by several airports. However, the assump- tion is that shift personnel being released early will go home and get some rest. A drawback to the procedure is that often the individuals are not able to get rest due to family activity, circadian rhythm functions, or other circumstances, so they return to work fatigued, provided the roadway conditions allow them to return. The duty time limitations can be imple- mented more easily if the airport provides rest and food facil- ities for its employees at the airport. Provide Sleep or Rest Facilities During major winter storms, it is not uncommon for airport employees to remain at the airport for days. Several small and non-hub airports indicated they have sleeping quarters or cots set up in the maintenance facility. However, a good rest environment was deemed just as important to the operators. At primarily medium-to-large-sized airports, resources exist to secure lodging for their personnel at local hotels, which several do. Provide Food and Drink Survey respondents indicated the provision of food was deemed an important factor in combating the symptoms of fatigue, and it also has been identified by the FAA in its research. The FAA has noted in its fatigue countermeasure brochure that eating frequently and wisely to prevent low blood sugar reduces the effects of fatigue (15). Some airports provide food or have it catered as a way to ensure proper nutrition for their employees. It also serves as a way to reduce the amount of time away from snow removal operations. Other airports will provide a snack pack for employees to take with them in the vehicle. Making sure the coffee pot is in good working condition is vital at many air- ports, though several respondents specifically mentioned the caffeine-potent “energy drinks” as an alternative. In a pre- liminary study, a specially formulated energy drink was found to have a consistent effect on sleepiness, lane keeping, and speed choice in traffic (39). Although caffeine can increase vigilance and decrease the feeling of fatigue, it can also postpone sleep (whether desirable

or not), impair the quality of the sleep that one gets, and can increase one’s heart rate and blood pressure. Too much caffeine and operators will have difficulty recovering from long hours of work because their rest or sleep time will not be very rest- ful. For restful sleep, the recommendation is for caffeine to be avoided for 6 h before going to sleep. A snow plow driver may find this difficult to do when completing a 12-h shift and having to return the next day. Caffeine normally has its peak effect 1 to 3 h after being consumed. Individuals who regularly use caffeine develop a tolerance to it and eventually need more caffeine to feel the same effect. This makes it more difficult to use caffeine “strategically,” because a lesser effect will occur when it is needed the most. Individuals who do not regularly consume caffeine will be more sensitive to its effects and, therefore, will find it easier to use caffeine strategically. Sensitivity to caffeine also changes with age so that as one gets older, one tends to get more of a “lift” from the same amount of caffeine. Provide Frequent or Adequate Breaks Based on the comments received in the survey, long hours are the expected norm during winter operations, especially at smaller airports that have fewer employees than larger airports. The comments received suggest that airport organizations do not typically plan increases in the number of employees dur- ing winter operations. Instead, they view the snow event as an anomaly that is to be managed using normal staffing levels and budgets. A normal solution to inadequate number of personnel is to increase existing employee hours but try to give them more frequent rest breaks. A second solution is to enlist build- ing maintenance or other non-airfield personnel. That activity can increase the risks of a vehicle–aircraft incident, however, because the individual’s experience and training in airfield operations may have lapsed. A best practice would be for air- port management to have an integrated training regime to keep individuals current in airfield operations. Frequent breaks were cited by a majority of responders as the way to mitigate the effects of fatigue factors. After getting adequate rest, the FAA has identified that standing up, stretch- ing, and walking around as much as possible is a prime method for countering the effects of fatigue. Associated with taking frequent breaks is the suggestion made by many survey respon- dents to break up the monotony of snow removal operations by rotating assignments or jobs. Rotate Assignments Rotating employees between plows, blowers, sweepers, and other assignments combats fatigue by allowing the use of dif- ferent motor skills and mental processes. The use of different skills and processes counters the boredom cited as a major cause of fatigue. Rotation every 4 h was the conventional wisdom expressed by respondents. 26 Consider Ergonomic Factors Previously noted as a fatigue factor was the design and/or ergonomics of the vehicles used in winter operations. It is no surprise that a solution to that issue is to have newer vehicles with better seats, increased comfort, reduced noise levels, and better ergonomic layout of controls. Other Under the last broad area of survey response are a number of technologies and suggestions that point toward both the orga- nization and the individual for managing the fatigue factors associated with winter operations. The simple act of rolling the window down to get cold air, or keeping the plows going and not stopping, using radio chatter and humor to keep spir- its up, and talking to oneself to remain focused, all point toward the motivational aspects of combating fatigue. One respondent suggested as a motivator to remind every one of the overtime pay they would receive. Although self-motivation can be a deterrent to fatigue, organizational efforts to manage fatigue are more effective. Having supervisors closely monitor the efforts of the snow removal crews for signs of fatigue; upper management sup- port of policies to provide duty limits, adequate breaks, job rotation, sleeping quarters and food; or reducing stress and managing expectations of personnel through budget expendi- tures and well-planned options for bringing in support per- sonnel are all examples of how an airport can indirectly reduce gaps that exist in the risk factors involved in winter operations. A well-thought-out SMS can create an organization that will support such efforts. The following case examples of fatigue are from the ques- tionnaire responses. • At one large-hub airport, the approach to mitigating fatigue factors is as follows: Personnel are on duty around-the-clock during a snow event. Bunk, locker rooms, and shower facilities are provided. Crew scheduling was based on previous US DOT over-the-road regu- lations. During extended events, the full crew is broken into half or thirds to facilitate rest periods. Personnel are on the clock when they are sleeping. At airport insistence, equipment manu- facturers have allowed vehicle operators to have input into the design of new operator cabs that feature improved ergonomics, better climate control, improved visibility, and user-friendly controls. The lack of cup holders was one of the largest operator complaints. We encourage operators to communicate to a man- ager that they are becoming fatigued. Breaks will be scheduled with no consequences to the individual. Five-minute cat naps (proven to alleviate short-term fatigue) are allowed in a vehicle, as long as that vehicle is parked in a safe location. • Another large-hub airport takes the following approach: The airport operates two separate teams that work six (6)-hr shifts. The shifts start and stop 0600, 1200, 1800, and 0000 hrs.

27 The basic rule is to switch at these times unless vehicle move- ment started within an hour of one of the start-stop times. This is the operator’s time to eat, sleep, and shower. The Authority has kitchen staff that prepares breakfast and lunch. Meal times are 0500-0730 hrs for breakfast. Lunch is from 1100–1330 hrs. These times allow for both teams to eat if they choose to. Dinner is at the Marriott located on the airport property. • A small-hub airport shares its lessons as follows: In the past, we used to have the same crews here to work a snow removal operation for as long as it took. There were times when the crew spent numerous days on airport property without get- ting home. Now, we have attempted over the past few years to split our crews into separate work crews during different times of the day. Due to our decreased amount of traffic here, after 2300 each day, we attempt to ensure that we have one of our main runways cleared and clean for any arrivals/departures between 2300 and 0400. We either give some of the workforce time to get some sleep who are here on site, or have a fresh group of per- sonnel who have been home resting get underway with a full field snow removal cleanup starting at approximately 0400 for the morning aircraft operations. This, too, has worked out well for us. • From a non-hub airport, their approach is as follows: This year we are going to have 2 crews so we can have someone on the field at all times. They will be on 7-hr shifts. First crew will be on duty while the other crew is on break to eat, shower, and sleep (they are paid for the whole time). • Another non-hub airport took the following approach: We keep water on the field to keep the drivers hydrated, we try to give drivers mental breaks between each runway plow opera- tion, and when possible we try to swap out our plow drivers. We also have a lot of discussion on the radio from the supervisors to keep staff engaged and on track. The FAA has produced a report (27) that details some of the factors affecting fatigue in aviation operations. In that brochure some of the myths and truisms that apply to fatigue are presented. Those factors have the following effects (27, pp. A5–A6): ALCOHOL Drinking alcoholic beverages may help you to fall asleep faster, but it will make the quality of sleep that you get worse than it would have been if you had no alcohol. LIGHT, HEAT, and NOISE Sleep in a cool, dark, quiet place. Constant “white noise” (like the hums produced by air conditioners and fans) help to cover up other noises, making them less likely to disturb your sleep. PAIN RELIEVERS Some pain relievers can also interfere with getting enough sleep. In one study, people who were in no pain and given aspirin or ibuprofen (e.g., Advil®, Motrin®) before bed, woke up more often and spent more time awake during the night than when they took acetaminophen (e.g., Tylenol®) or a placebo. SMOKING Nicotine is a stimulant and cigarette smoking can interfere with sleep. CAFFEINE Everyone knows that drinking coffee near bedtime can make it difficult to get to sleep. What you may not know is that caffeine can also disrupt sleep even in people who fall asleep easily after consuming caffeine. For a better night’s sleep, avoid caffeine for six hours before bedtime. TIPS FOR MAINTAINING ALERTNESS ON THE JOB: Now that you know how to get a good night’s (or day’s) sleep, here are some other tips to help ward off fatigue and keep you alert: • Stand up, stretch, and walk around as much as possible. • Eat frequently and wisely to prevent low blood sugar. • Spend break time under bright lights. • Wearing sunglasses changes the appearance of colors on a dis- play and can increase your chances of mistaking one color for another. • Certain medications can affect your color vision. For example, Viagra® (sildenafil) can affect the ability to tell the difference between green and blue. This information is presented because many respondents to this synthesis study thought differently about the effects of these factors. There are also a number of fatigue management technolo- gies that are becoming available to help maintain operator alertness and performance levels by detecting operator fatigue and interfacing with the operator and/or supervisor to prevent accidents and incidents (17, 40). Examples of such technology are eye-gaze detection systems, head-nod detectors, vehicle monitoring systems, in-seat vibration systems, physiology/ behavioral devices, and mental reaction time tests. Use of fatigue management technologies in the airport setting was not indicated by any of the respondents to the questionnaire. Human factors have long been recognized for its role in producing errors. For winter operations, fatigue is a major human factor that needs to be better addressed in the train- ing efforts of airport organizations. Recognizing the symp- toms of fatigue is an SA issue that all vehicle operators and airport organizations need to address in their training and operations. SUMMARY Chapter five discusses how fatigue is widely recognized as a core safety issue in the air transportation industry, with it being on the NTSB’s most-wanted list for safety improvements in aviation. However, fatigue has not been readily studied within airport operations and, in particular, snow removal operations. The review of airport snow plans indicated that fatigue countermeasures were not part of an airport opera- tor’s SICP or training regime, nor were they even mentioned. Recognizing when one is fatigued and taking action to counter it are two important components of a safe operating system. The chapter provides a basic understanding of fatigue and stress and ways to manage each. When survey participants were asked to list the factors that contributed to driver fatigue or impairment, the factors cited

could be grouped into the following general areas: long work hours without breaks, irregular time, stress, boredom, envi- ronmental conditions, vehicle design and ergonomics, per- sonal health, and staffing. Stress and its causes are discussed as a factor affecting human performance. Stress was found to emanate from such things as the need to keep the runway open, to not cause harm or damage, to get things done quickly, to satisfy other’s demands, and to satisfy demands by aircraft wanting to operate on the movement areas. Other sources of stress that were cited were home life, job satisfaction, and the drive to work itself. Stress adds to the fatigue factor. 28 The literature identified factors such as time of day, the amount of prior rest, and the timing of rest breaks as being central to managing fatigue. Respondents identified limiting duty time, providing sleep or rest facilities, providing food and drink, providing frequent or adequate breaks, rotating assignments, and paying attention to ergonomic conditions as all being means to enhance human performance. Properly managing fatigue and stress requires both individual and organizational efforts. In this chapter, lessons are shared from airports as to how they address the collision risk factor of human performance at their airports.