Longread: The story of a flight

When we all think of fatigue, the first thing that comes to mind is early and night flights. But as ICAO defines it, fatigue is also a consequence of workload that, by itself, can cause sufficient impairment to a crew member to be considered a hazardous situation and thus having to be managed under the SMS rules, if not by a more complex system: the so called FRMS. But is there enough in that daily operation that can overflow aircrews to a point of near rupture?

Let’s go fly. It’s 04am and the alarm clock just rang for a 06am reporting time. After your daily morning routine, you drive 30min just to get to a crowed crew room. After all you are not the only one to depart this early in the morning. The hassle of getting briefings, discussing them and get everything ready takes some time, around a rushed 20min, as holding it longer would grant you a late arrival at the aircraft and a delayed flight. First checklists done, some issues discussed with the dispatcher and passengers are on their way. It is a full flight, where the time now is to close doors and push back. As you and some other 5 or 10 aircraft get on their way to the runway the ATC frequency gets really busy and communicating goes from a standard task to a job of great care and attention. At the same time, as the airplane is rolling, checklists and standard operating procedures need to be completed so everything is completely ready upon reaching the runway. The all cleared to take off finally arrives, and as we are just crossing 1500’, reducing our thrust levers and getting the air conditioning set, that ATC call comes through for a frequency change. We reached his handoff point. The next guy comes in, we are about 1000’ to level off, squawk ident and time to start our first turn. After takeoff checklists done, and we are on our way. And it’s only 07:30 am, a mere 01h30 after our work day started, but 3 hours after the alarm clock rang this morning.

A few bad weather deviations and some turbulence dictate the climb, as in the noisy cockpit everything shakes and moves through the climb. Some ATC frequencies later and a bunch of headings to avoid traffic we reach cruise altitude. But as this is just a short hop, a snack and some 20min of paperwork and we are due to descend. And it starts all over again. The level and heading restrictions, the TCAS symbols showing all sorts of traffic, the endless frequencies of the still much fragmented airspace bellow us. It is time for final approach, just a standard ILS with a 35kt crosswind and some moderate turbulence that leads us to our gate on that 08:30 am arrival. And the turnaround cycle begins, a 30 to 40min stay and off we go again to our next destination.

As we are being optimized, it all repeats itself again, and again on a more than usual 4 sector flying day. Maybe it won’t be with a 35kt crosswind. Maybe it’s a training flight, a special class C airport or low visibility operation with winter weather. But nevertheless it’s 4 flights in just under 12 hours, with all the adverse effects that it has on the human body on a physiological and mental level.

The fact is that automation does not replace the human body in the most important matters. It only helps to alleviate the manual workload so it can better concentrate on the mental demand that the task of flying today requires. But although we can easily define this concept, the big issue with workload and its relationship with fatigue is how to measure it. Bio-mathematical models, top of descend surveys or fatigue reports together with Psychomotor Vigilance Task (PVT) testing or the more recent and specific cortisol tests (amongst others) are all perfectly good ways to measure objective and subjective fatigue. But the real truth is that none of them really measures or predicts workload.

Let’s take bio-mathematical models as an example: they can be a two or even three process models, with increased levels of complexity in computation methods. But when looking at its genesis what lies behind it, is simply and solemnly the circadian and homeostatic rhythms. Of course we can set an individual as being an ‘evening’ or ‘late’ person and could adjust schedules to its optimum performance time. But even at its optimum time a crew member can experience high levels of task-related stress and anxiety, and that is the difficulty and challenge – among others – with the concept of workload.

A good help to better perceive and manage workload could be perhaps by introducing the concepts of active and passive fatigue into aviation and risk management. By definition, active fatigue can be set as the one where a big amount of physical activity takes place, opposite to passive fatigue where the crew usually takes on a supervisory role and monitoring, generating a big level of mental (and often monotonous) workload for a long amount of time, thus reducing safety margins by time on task. Of course that, despite the division we are always talking about fatigue: an issue that can affect the senses and induce the same high levels of stress and adrenaline, being dangerous to human perception, attention and reaction capacities, amongst others.

Taking this into consideration, it is quite easy to see that the same task can have as many outcomes in fatiguing a subject as the times it is executed or repeated, being also very dependent on the time of day, environment or even on something as simple as personal predisposition ay the moment that the task is executed. A good example is landing an airplane: if it is a 4 or even 6-sector day we can discern clearly that there will be peaks of workload and through accumulation, the individual’s condition on the first landings will be very different from the last one. But if we take into account a 2-pilot 11h long Atlantic crossing, is it that obvious that the one and single landing done at the end can be less or even more tiring than that 6th one mentioned before?

So how can we manage not to be overwhelmed and too tired to be on task when it gets busy? We do know that help and support should exist through good and solid flight time limitations, but the one-size-fits-all remedy is definitively only a barrier – and only one barrier – but not the solution (which fails more often than desired). There is a huge responsibility that lies on the rostering and safety departments of an airline as it is not sufficient to schedule a set of flights by simply sticking to the prescriptive limits, set by EU legislation. There must be a risk assessment on fatigue that complements scheduling and that needs to be performed for the flight duties in accordance with the Safety Management System procedures.

That said, it is important to have into consideration the many different physiological and psychological influences in the human body and to account for all of them is almost impossible. That dog barking at 3am can be the recipe for a very long “2-short flights” day. And because it is often quite personal, the most viable and proved way to manage individual fatigue is a big “know yourself”, changing what can be changed to execute the task(s) at the personalized best time of the day. For this however, and for managing pilot fatigue across an airline, it is essential that “corporate fatigue risk management” (FRM) is in place. Such FRM includes that the crewing and safety departments are running good evaluations and safety cases – jointly and in partnership with flight crew representatives – that can bring out the best performance possible to each crew member. While fatigue is to be considered as a safety risk like any other operational risk, and must therefore be evaluated and managed under the SMS procedures, specific FRM and FRMS are what is needed to take a proactive and preventive approach. Crucially, such FRM can only work if pilots and cabin crew are actually reporting fatigue. And as we all know, they will only do so in a ‘Just Culture’ environment where they feel confident and encouraged to report incidents – including fatigue – and thereby provide essential safety-related information to the company without fear of blame or punishment.

In this very serious game, that aviation is, we must never take our eyes away from the ‘safety ball’ and the environment where it plays. And for sure inside that ball fatigue and workload fill up a big and important portion.

by Pedro Alceu, pilot and member of the ATM Working Group of the European Cockpit Association.


Read more on Fatigue Risk Management in ECA's Position Paper (2015)