[Peetwo]

Fatigue - in another hemisphere.

While on the subject of fatigue and our still obstinate regulator's reluctance to embrace real science and human factors current day (21st vs 19th century) research/findings and practises on the subject, the following is an excellent BCA article that once again reveals the real insidious nature and safety risk of fatigue -  :

Flying Tired: Recovery From Sleep Loss Is Not So Simple
Jul 20, 2018
Patrick Veillette jumprsaway@aol.com | Business & Commercial Aviation


Many of us as youngsters yearned to become pilots. We envisioned the “glamorous” jet-setting lifestyle with plenty of comely companionship on trips to exotic locations like Rio, Tahiti and Paris, feasting on the local cuisine and strolling along wide beaches and narrow cobblestone streets. Little did we know that the occupation would involve long duty days, early starts, multiple time zone changes, uncomfortable hours confined in a tight cockpit while breathing desert-dry air and forcing ourselves not to nod off.

John A. Caldwell, Ph.D., co-author of Fatigue in Aviation, is an internationally recognized scientist in the area of sleep deprivation and fatigue countermeasures. He asserts that “fatigue-related performance problems in aviation have been consistently underestimated and underappreciated” despite decades of research on pilots showing that insufficient sleep significantly degrades cognition, psychological mood “and fundamental piloting skills.”
[/url]

Image Source: istockphoto


None of us are immune to the problems of fatigue. If you have found yourself or crewmates overlooking or misplacing sequential steps, becoming preoccupied with single tasks, having a greatly reduced audiovisual scan and being less aware of poor performance, then welcome to the brotherhood of the flying weary. Other notable warning signs of fatigue include being less likely to perform low-demand tasks, becoming more distracted and more irritable, and finally succumbing to a “don’t care” attitude.

The only way to recover from fatigue is to get adequate rest. Unfortunately, that’s often not an option. Dr. Curtis Graeber, who served as the human factors specialist for the Presidential Commission on the Space Shuttle Challenger Accident, joined [url=http://awin.aviationweek.com/OrganizationProfiles.aspx?orgId=19991]NASA Ames Research Center in 1981 as the principal investigator for a congressionally mandated study of fatigue and circadian rhythm factors in flight crews. The NASA research team found that the sleep deficit for a tour often begins before showing up for the first trip, especially if the report time involves an early wake-up. Under such frequent circumstances, the average pilot reports for duty on day No. 1 with a sleep deficit. Strike one.

If you feel that your sleep on the road is less restful that your sleep at home, you aren’t alone. NASA studies found that the average pilot sleeps an hour less per night during layovers than at home due to the significant increase in awakenings while in hotel rooms. Such sleep disruption is known to result in daytime sleepiness. That’s strike No. 2.

Let’s say you flew the “back side of the clock” and dragged your weary bones into the hotel room at 5 a.m. How many times has the chambermaid knocked on your door a few hours later loudly proclaiming, “Housekeeping,” despite the “Do Not Disturb” sign you hung on the exterior doorknob? And is it too much to ask hotels to put a “quiet close” device on guest room doors so that guests can’t slam them shut?

The quality of the sleep environment is an important contributor to rest and recovery, yet we pilots have no control over it and simply have to endure less-than-restful nights when on the road. That’s strike No. 3. But wait, there’s more to the fatigue problem.

Have you felt yourself getting even more tired during the progression of a tour? This, too, is commonplace since the lack of adequate rest accumulates. This “sleep debt” or “sleep deficit” is real and a real problem. Consider this: You have the dreaded 5:00 a.m. show on day No. 1 of a trip beginning at your home base at Van Nuys Airport (KVNY) in California for a nonstop to Chicago Midway Airport (KMDW), where you pick up additional passengers and continue to New Jersey’s Teterboro Airport (KTEB). Depending on your driving time to the FBO at Van Nuys, it’s quite possible you had to wake up at 3 or 3:30 a.m. Once at the New Jersey hotel, you might try to sleep around 7 p.m., but there’s the call home, shirt pressing, emails and such, and it’s more likely you’ll be lights out at 11 p.m., your normal sleep time. You’ve made it through the day with, maybe, 4 hr. of sleep. Any normal pilot would have felt groggy all day long.

The next morning, you’re bound for Toronto’s Pearson International Airport (CYYZ) with a departure time of 7 a.m. With the paperwork for the international trip you plan to be at the FBO no later than 5:30 a.m. local, which translates to a 4 a.m. wakeup. Will you drop immediately into deep restful sleep? Not likely.

According to Graeber, when sleep is attempted at a time abnormal to a person’s circadian rhythm, that person will have considerably more difficulty getting to sleep and, once successful, will usually awaken within a relatively short time. This is one of the key underlying problems for pilots that creates what is essentially a career-long battle with fatigue. Simply stated, humans get their normal recuperative rest when they go to sleep at their normal time, and wake up at their normal time. Doing otherwise substantially cuts down on the quality and quantity of sleep. We can’t simply “switch ourselves into deep sleep” just because the crew schedulers tell us this is our 10-hr. rest period. Let’s call this strike No. 4.

Then, when the alarm clock jolts you awake in Teterboro — which, by the way, is 1 a.m. on your California body clock — you can be forgiven for reconsidering your career choice. How much deep recuperative sleep did you manage to get? Clearly not enough. Perhaps it was 4 hr. of deep sleep, thus starting day No. 2 with an accumulated 8 hr. of sleep debt. That’s the equivalent of missing an entire night of sleep. Let’s designate the sleep debt issue as strike No. 5.

Changing time zones or operating on the back side of the clock imposes the additional burden of circadian desynchronization. Graeber’s research found that the circadian rhythm system is unable to adjust rapidly to sudden shifts. In effect, the system resists changes in its timing and stability and complete resynchronization of the body’s biological timing system can take several days.

Additionally, resynchronization occurs at a different rate depending on whether the body must adapt to a westbound or eastbound time zone changes. Medical specialists in the field of sleep medicine have determined that, depending on the number and direction of time zones crossed, it can take days for the circadian system to resynchronize. And recovery from eastbound flights is more difficult. The general rule of thumb is that adjustment to eastbound travel requires 1.5 days per time zone crossed. Yet, as pilots it is entirely possible to be in a different time zone each night of a trip. In short, we don’t get days to resynchronize. Circadian rhythm desynchronization is strike No. 6. Two batters down.

There are substantial differences in various people’s ability to adjust to repeated time-zone shifts. “Morning people,” introverts, the elderly and those with stable rhythms have slower rates of resynchronization than others. Furthermore, studies found that crew members over 45-50 years of age experience less total sleep and poorer quality sleep. If you’re in this age group, that’s strike No. 7.

The combination of poor sleep quality on the road as well as trying to sleep at times outside your body’s normal sleep time will worsen the sleep debt during the trip. It comes with the job. NASA research found that air crews tend to accumulate more sleep debt and thus become more fatigued as they progress through a trip.

Does working a pilot hard contribute to fatigue? Yes, it can, but if the pilot is operating during a normal “day” cycle and then has the opportunity to rest during a normal “night” cycle, the average aviator will be able to show up for flight duties the next day adequately rested.

I have asked pilot groups if they would rather work a hard 12-hr. day that begins at 7:30 a.m. or work an 8-hr. day that begins at 5 a.m., and they almost always choose the former. Why? The sleep loss associated with early morning report times is considerable. NASA research found that the timing of flight activities and not necessarily the length of the duty day or the number of segments flown appears to contribute more to fatigue.

You would not be alone if you dread the fatiguing effect of those early report times. (And admit it, how many of us set at least two alarm clocks for those early morning wake-up’s?) An early report time is strike No. 8.

The British Association of Airline Pilots, together with the University College London Psychobiology Group, carried out a survey of fatigue and well-being among British airline pilots. The study revealed that sleep problems are correlated with fatigue. As a consequence, fatigue can become self-perpetuating. It determined that “Pilots may eventually end up in the vicious circle of being too tired to adequately rest or sleep, which in turn will leave them even more exhausted.” (See the “How Bad Is the Problem?” sidebar.)

Dr. David Gozal, both a professor at the University of Chicago School of Medicine specializing in sleep disorders and a deputy editor of the journal Sleep and Frontiers in Neurology, found that recovery from sleep loss does not immediately restore all of the body’s systems. Neural and metabolic activity take much longer to recover. “Recovery is not so simple,” he found, adding, “If you accumulate debt, there will be compounded interest and an uphill battle to recover.”

Up to this point I have not touched on pilot duties in a typical day, the stresses involved, and the fatigue-inducing conditions under which we work. A 6 a.m. show in January for clients who enjoyed a weekend of skiing at a ski resort means you are likely walking out to an aircraft that has been cold-soaked to -20F on the ramp for maybe the last three days. Preflighting such an aircraft on a still-dark morning in the mountains can be breathtakingly unkind. Conversely, getting an aircraft ready for a post-maintenance inspection flight on an August afternoon with the ramp radiant temperature spiked at 120F will spike crew fatigue levels as well.

Let’s say your departure is from New York’s Westchester County Airport (KHPN) on a Friday afternoon with weather all around when your lead passenger shows up with an additional golf buddy for the trip to Bermuda. Suddenly, you have additional customs paperwork to file as well as new weight and balance to calculate that could cause a cascading set of changes on your loading and fuel. Naturally, the principal expects the engines to start turning as soon as he steps aboard and to be rolling within minutes, oblivious to the considerable stress imposed on the crew.

Entering New York airspace at that time and day along with foul weather guarantees a high workload environment for the departure with controllers issuing nonstop instructions as they try to keep the metal moving. You will not really catch your breath until climbing through FL 300.

The view from the flight deck at FL 410 on a clear day is one we would never trade, but the cockpit itself contributes to fatigue. Sitting confined in small seats for long hours induces lethargy, as well as our chances for developing deep vein thrombosis, or DVT. The dry, pressurized air is wicking away precious volumes of our body’s moisture, thus causing us to be in a chronic state of dehydration for most of our hours airborne. Glare, vibrations and noise all increase fatigue. How much does the combined effect of these add up? The anecdotal evidence suggests it is considerable. (See the “Cockpit Environment and Fatigue” sidebar.)

Despite the forging, most of us are Type A personalities who seek out challenges and enjoy the sense of doing a job well. So, as a group, we are not very good at stepping away from the plate and saying, “Coach, I need to sit this one out.”

In the words of Steven R. Hursh Ph.D., chief scientist of the Institutes for Behavior Resources, “There’s no breathalyzer for tired . . . but there should be.” Absent a practical real-time fatigue detector, he says most people underestimate just how tired they are and how impaired they are by that fatigue. 

Admonishments to “be more professional” or “show attention to detail” ignore the underlying pervasiveness of serious fatigue among line pilots. Professional aviators will continue to be warned to use their rest period productively, even though the scientific evidence is plentiful that the human body simply does not flip a switch at 6, 7 or 9 p.m. to begin deep recuperative sleep in preparation for a 3 a.m. report for duty the next day. It is the timing of sleep, not the amount of time awake or “in rest,” that is the critical factor controlling sleep quality.

The facts about fatigue are clear, and something to sleep on. 

   
Even though I might appear to be 'flogging a dead horse' Downunda; I note that the AA magazine last week refreshed the informative BC June article on 'understanding fatigue':   

THE HUMAN FACTOR: UNDERSTANDING FATIGUE

written by Ben Cook July 21, 2018

THE SIGNIFICANT IMPACT OF FATIGUE

Last issue we highlighted the significant impact fatigue can have on crews. In the case of the Pel-Air Westwind ditching, the aircraft captain, having obtained only 3–3½ hours of average quality sleep, displayed a fixation on a simple plan to land. He and the remainder of the crew were too impaired to recognise growing evidence that the plan was not working. The flight nurse and doctor received minimal to no sleep during the day of the accident as they were too busy caring for the patient.

Even worse, the accident itself occurred on a remote island around 9.40pm, yet the crew were meant to be continuing from Norfolk Island to Sydney and then to Melbourne. This was well outside the acceptable limits of any mature fatigue risk management system (FRMS). This information has gained little attention even though it’s a clear example of failed company processes and regulatory oversight.

The impact of elevated levels of fatigue is that people do not realise their level of impairment. They press on ‘lethargic and indifferent’ with a simple plan. This can occur in large organisations to even the most experienced crews.


Pel-Air Westwind VH-NGA at Sydney AirportPel-Air Westwind VH-NGA at Sydney Airport (Tim Bowrey)

THE INSIDIOUS NATURE OF FATIGUE

A clear wake-up call across international civil aviation was the 1993 crash of a DC-8-61 freighter while on approach to land at Guantanamo Bay, Cuba. It was one of the first accidents where fatigue was cited as the primary contributory factor. The US National Transportation Safety Board (NTSB) determined the probable causes of this accident were the impaired judgment, decision-making and flying abilities of the captain and flightcrew due to the effects of fatigue. Acute sleep loss contributed to degraded decision-making, visual and cognitive fixation, poor communication and slowed reaction times.

Leading up to the accident, the three crew members had each been continuously awake for 23½ hours (aircraft captain), 19 hours (first officer), and 21 hours (flight engineer).

The outcome being a loss of stabilised approach criteria and an uncontrolled in-flight collision with terrain. The aircraft captain who, like his copilot and flight engineer managed to survive this accident. They regained consciousness post-accident in “what felt like a crunched-up coke can, with wires and panels hanging all around them”. Luckily during the impact, the front part of the cockpit separated from the main fuselage and kept the crew away from the subsequent fireball that erupted as their four-engined jet transport crashed into the ground.

Earlier that day the crew knew they were going to be exposed to elevated fatigue risks and had planned to make a more conservative approach, rather than an approach that required visual guidance from a ground-based strobe light (that on the day was not working).

However, after receiving a request from air traffic control very late in the flight, when fatigue levels were excessive, they elected to change their original plan to a far more demanding visual approach that required steep manoeuvring to make the landing.This was all at the captain’s suggestion, “Just for the heck of it”. During the final minutes of the flight, the cockpit voice recorder (CVR) clearly highlights the negative effects of fatigue.

These include cognitive fixation (too focused on identifying a strobe light to the detriment of other cues), and pattering checklists by rote but not having the cognitive ability to recognise and act on other critical information such as airspeed control or verbal cues that the aircraft was well outside safe parameters.

COCKPIT VOICE RECORDING:

FE: Slow. Airspeed.

FO: Check the turn.

Capt: Where’s the strobe?

FE: Right over here.

Capt: Where?

FO: Right inside there, right inside there.

FE: You know, we’re not gettin’ our airspeed back there.

Capt: Where’s the strobe?

FO: Right down there.

Capt: I still don’t see it.

FE: [Expletive], we’re never goin’ to make this.

Capt: Where do you see a strobe light?

FO: Right over here.

Capt: Gear, gear down, spoilers armed.

FE: Gear down, three green, spoilers, flaps, checklist.

???: There you go, right there, lookin’ good.

Capt: Where’s the strobe?

FO: Do you think you’re gonna make this?

Capt: Yeah… if I can catch the strobe light.

FO: 500, you’re in good shape.

FE: Watch the, keep your airspeed up.

FO: 140.

 [sound of stall warning]

???: Don’t – stall warning.

Capt: I got it.

FO: Stall warning.

FE: Stall warning.

Capt: I got it, back off.

???: Max power!

???: There it goes, there it goes!

???: Oh no!

 [screams]

EXPERIENCED CREW

This crew were highly experienced (far more experienced than the Pel-Air crew), yet they too lost the ability to recognise what, in hindsight, look like obvious cues to us, that could have broken the error chain. The aircraft captain (Jim Chapo) had more than 20,000 hours flight time. He had served as a check pilot with a major commercial airline prior to commencing night cargo work. But, he received no specific training on the effects of fatigue, even though the night cargo work was quite different to the rosters he had experienced with the airline.

As part of an NTSB fatigue factors training course I attended,  I was fortunate to hear a presentation from Jim. He reported feeling “lethargic and indifferent” during the approach and, when he later reviewed the CVR, was surprised at how unresponsive he was to the concerns of others.  It was an emotionally moving presentation to listen to Jim so openly and honestly recount the horror of surviving an accident and the long-term trauma that followed. At the time, the crew were operating in accordance with the regulations and company procedures. It further highlights the true dangers of elevated levels of fatigue and the severe impairment to decision-making and cognitive processing.

Your challenge, in making sure you utilise human factors for high performance, particularly if you’ve made a transition from one type of operation to another – for example, ab-initio flying training to night freight operations – is to make sure you identify such gaps. True high performers don’t accept the status quo. They know their own limitations and they continue to respectfully seek the training and/or enhanced processes necessary to ensure they can maintain proficiency.



Miraculously the crew of the Guantanamo Bay DC-8 freighter crash survived. (NTSB)

PSYCHOPHYSIOLOGICAL INSOMNIA
One of the biggest challenges of fatigue is that certain conditions experienced by one person may have little to no impact on performance, yet another person under the same conditions can be severely impacted.

I’ve been fortunate over the years to gain some detailed operational experience in managing fatigue, including the use of specialist sleep watches to obtain real sleep data. This has involved the development of fatigue risk profiles, not as an academic research project, but rather for the management of a known hazard (fatigue) with the constraints of a safety management system (SMS).

So, look at the following real patterns of sleep, which are shared with consent. The first data column contains 10 consecutive days of sleep hours and minutes during a time when a student was completing a very demanding aviation training course on a high-performance aircraft. The second column contains 10 days of consecutive sleep data for the same person, though this time the person is performing an instructional role.





FIT FOR DUTY?

What are your thoughts? Is this person fit for duty?

I hope you want to ask some further questions. As background, this person does not have a short sleep gene – they’re not one of the less than three per cent of the population that can perform well with much less sleep than most of us. In fact, when on holidays and relaxing (a good way to identify your normal sleep patterns) this person records seven–eight hours of sleep per night.

What’s your answer? Is this person fit for duty in any workplace, let alone within the cockpit of an aircraft? If you’re like most, including several sleep doctors, the answer is no.

LONG TERM HEALTH IMPACTS

Yet this person performed to a high standard throughout the duration of a particular training course. The bigger challenges were the longer-term impacts to the individual’s health and wellbeing.

I remember asking this person, when they were an instructor, their partner’s views on the impact to their sleep patterns. The response: “They just wanted their old partner back”.

It was at this point they sought specialist help from a sleep clinic to re-correct their sleep patterns, including techniques to manage the anxiety that was leading to poor sleep. While this person might be praised for their ability to perform well under such trying conditions, you need to be careful to not consider this as acceptable. The reality is disrupted sleep patterns like this over the longer-term lead to poor health outcomes. It’s also important to consider others that may not be able to perform like this, particularly if the additional stressors (such as a busy conversion course) are quite high and are actively contributing to additional anxiety and disrupted sleep. If, combined with a late night or very early morning simulator runs, you may be failing more than capable personnel at great cost.

HUMANS ARE COMPLEX YET WE SEEK SIMPLE SOLUTIONS

For most of us within our aviation organisations, life is pretty busy. We often seek simple solutions; it helps us tick off our task list and to move onto the next priority of the day. Only a fool dare tread in this space when dealing with human fatigue. For supervisors, you’re probably after a simple set of rules that not only define a broad limit for scheduling practices and fatigue management, but that can be used to make sure people conform to general work practices.

For example, if most of the team can handle a night shift in accordance with the rules yet one team member (we’ll call him Chris) cannot, what assumptions do you make? Have you ever heard phrases such as, “Chris is lazy”, or “Chris just doesn’t cut it in this workplace”? Chris may be more than competent to perform most tasks required to a high standard, it’s just that Chris’s individual biological differences result in a small part of the workplace routine not meeting his needs.

In mature organisations, these differences are understood and managed to align workplace practices to better support individual needs and to better understand the true complexity of fatigue. Yet so many organisations prefer the overly simplistic approach and along the way they lose good people like Chris, or even worse, they create a ‘them and us’ culture between workers and supervisors/managers.

The outcome is often catastrophic. After an accident, workers may state: “We knew that was going to happen, fatigue has been a problem for some time, why wouldn’t our managers listen to our concerns?”. In turn the managers respond: “We’ve got a fatigue risk management system and there’s nothing in there that suggests we had any problems”.

Simple tools applied to complex problems tend to erode confidence and trust in the fatigue management system and can decrease the open and honest exchange of information regarding the real problems.

SYSTEMATIC FAILINGS

As per the previous Pel-Air article, there were numerous systemic failings, and the following highlight typical findings that contribute to degraded levels of trust, which can ultimately lead to blind compliance of poor practices:

- Westwind pilots reported the rostering of their duty periods appeared to be heavily based on a fatigue score. They were never asked about their level of alertness or recent sleep when tasks were assigned, or during the progress of a trip.

- Some pilots indicated they were provided with insufficient information about the fatigue program and they did not understand how it produced its scores or why its scores seemed to be inconsistent with their perceptions of their own fatigue levels.

FATIGUE MODELLING TOOLS

For anyone experiencing similar outcomes, particularly if your company is over-reliant on a biomathematical model of fatigue (BMMF), then look at the following finding regarding limitations with simple tools and/or not validating such tools in close consultation to ensure the model matches the performance outcomes of the operational workforce:

The US Federal Railroad Administration (FRA 2010) compared a local Australian fatigue modelling tool with another BMMF model, the Fatigue Avoidance Scheduling Tool (FAST), which the FRA had previously validated for use in the rail industry. Based on this comparison, it concluded the local fatigue model scores between 70 and 80 can be associated with ‘extreme fatigue’. If there has been very little duty time in the previous seven days, the local fatigue model will underestimate the potential fatigue level associated with the next duty period, and at times this level of underestimation can be significant.

Yet many local operators continue to utilise scores between 70–80 under the watchful eye of the regulator. If you’re experiencing this type of FRMS then stand up as a human factors practitioner of high performance.  Make sure you utilise any reporting mechanisms available to ensure you don’t experience the same outcomes as the crew of the Pel-Air aircraft.



The primary cause of the DC-8 crash was crew fatigue. (NTSB)The primary cause of the DC-8 crash was crew fatigue. (NTSB)

WRAP UP

As humans we’re complex systems with our own unique biological needs. The combination of disrupted sleep, anxiety and/or fatigue (physiological degradation) remains one of the most significant contributors of degraded performance and increased errors, including eroded decision-making. A good starting point in any workplace is to better understand the multiple factors that can contribute to excessive fatigue. It is also critical in larger organisations to develop a high trust relationship where people are comfortable to report sleep and fatigue issues to ensure policy and process can be enhanced.

If you’re a smaller operator then the best you can do is to educate yourself on relevant fatigue factors and to make changes to your own habit patterns for enhanced outcomes.

FATIGUE CHECKLISTS

Given the importance of sleep and fatigue management, in consultation with a number of local human factors and sleep subject matter experts, Australian Aviation has made available the following support tools on our website:

- Fatigue investigation checklist: a simple checklist, as collectively developed by several civil and military organisations to provide enhanced guidance to determine whether fatigue contributed to the incident or accident. Download here

- Fatigue risk management chart: a list of some of the many factors that should be considered in determining whether fatigue risk is unacceptable. The chart is particularly good for personnel to better understand the main factors that influence fatigue. Download here

- A guide to a good night’s sleep: some extracts from a definitive book, A complete guide to a good night’s sleep, written by Dr Carmel Harrington, one of our local leaders in sleep science. The extracts provide practical insights from over 20 years of applied sleep science. Download here


This article first appeared in the June 2018 edition of Australian Aviation.

MTF...P2