Generally speaking, ‘Fatigue’ is predominantly influenced by sleep loss and circadian rhythm disruptions (Salas & Maurino, 2007). Fatigue is not a problem that is specific to one area of Aviation. All forms of aviation are at risk. While much of the research focuses on long-haul aviation, a lone GA pilot battling cognitive overload can quickly turn into a fatigue-crisis (Guastello et al., 2012). In addition, few General Aviation pilots have adequate training or resources to detect onset, and/or remedy, Fatigue (Harris et al., 1995)
GA would benefit from a simple model that can consume simple parameters such as flying conditions, route of travel, pilot health, sleep history, pilot flying history etc. and provide a risk score to a pilot based on which a decision to fly can be made.
I believe that even knowing that there is a level of risk given all the parameters that exist is a great thing to have. The IMSAFE checklist is good, however, when one goes through the checklist it is indeed hard to have a true assessment. I have seen many times that GA pilots run through teh checklist quickly and decide to fly. However, I have often thought whether a GA Pilot would reject a decision to fly based on knowing that the pilot has had a growing sleep deficit over the past week or month; or whether a forecast indicated sharp temperature drop between altitudes (indicating turbulent air in that region) combined with a sleep deficit should deter a pilot from flying that day.
Fatigue can occur pretty rapidly even in a fully fit individual in a GA cockpit (with little automation). When combined with other factors, the situation can unravel very quickly (Salas & Maurino, 2010). I know from experience that there have been days when I have gone out for a recreation flight in the local area and after battling turbulent air in single piston aircraft for 90 minutes, I have landed and felt really worn out from the experience – add a situation of 4-5 hours of sleep the prior night and this fatigue multiplies multi-fold.
They highlight the mission-critical dependence on human performance in some industries or professions. I don’t believe that this dependence, or impact, is even comprehended by most outside these professions. I have felt that even working for an airline experiencing the pressures involved in keeping a real-time operation running optimally does not fully clarify the complexity. The body of literature on this topic is immense and just reading a few of the papers (infinitesimal, compared to the literature available) on the subject of shift scheduling in some industries has evolved my thinking on the topic. The references below indicate some of the papers that I found very helpful in getting to understand some basic facets of this subject. The integration of fatigue models into scheduling algorithms was a very interesting topic (Ta-Chung & Cheng-Che, 2014). One conclusion I draw… scheduling in some industries is not merely about managing time and people. It is multi-dimensional and mission-critical.
References
Barton, J., & Folkard, S. (1993). Advancing versus delaying shift systems. Ergonomics, 36(1-3), 59-64. doi:10.1080/00140139308967855
Caldwell, J. A., Mallis, M. M., Caldwell, J. L., Paul, M. A., Miller, J. C., Neri, D. F., & Aerospace Medical Association Fatigue Countermeasures Subcommittee of the Aerospace Human Factors Committee. (2009). Fatigue countermeasures in aviation. Aviation, Space, and Environmental Medicine, 80(1), 29-59. doi:10.3357/ASEM.2435.2009
Guastello, S., Boeh, H., Schimmels, M., & Shumaker, C. (2012;2011;). Catastrophe models for cognitive workload and fatigue. Theoretical Issues in Ergonomics Science, 13(5), 586-17. doi:10.1080/1463922X.2011.552131
Harris, W. C., Hancock, P. A., Arthur, E. J., & Caird, J. K. (1995). Performance, workload, and fatigue changes associated with automation. The International Journal of Aviation Psychology, 5(2), 169-185. doi:10.1207/s15327108ijap0502_3
Knauth, P. (1996). Designing better shift systems. Applied Ergonomics, 27(1), 39-44. doi:10.1016/0003-6870(95)00044-5
Salas, E., & Maurino, D. E. (2010). Human factors in aviation (2nd ed.). Boston, Mass;Amsterdam;: Academic Press/Elsevier.
Smith, L., Hammond, T., Macdonald, I., & Folkard, S. (1998). 12-h shifts are popular but are they a solution?International Journal of Industrial Ergonomics, 21(3), 323-331. doi:10.1016/S0169-8141(97)00046-2
Ta-Chung, W., & Cheng-Che, L. (2014). Optimal work shift scheduling with fatigue minimization and day off.Mathematical Problems in Engineering, doi:http://dx.doi.org/10.1155/2014/75156
