Phase Advance Occurs when traveling Eastbound – Day is shortened Forced to advance to new rhythm First sleep is short followed by subsequent longer rest period
Phase Delay Occurs when travelling Westbound Day is lengthened Initial sleep is longer followed by shorter sleep episode
Resynchronization Asymmetrical Effect – Difference between Eastbound and Westbound Westbound (8 time zones or more) – 5.1 days for 95% adjustment Eastbound (8 time zones or more) – 6.5 days Circadian Synchronization – Westbound (92 minutes per day) – Eastbound (57 minutes per day)
Sleep Propensity/Pressure Definition – The physiological need to sleep based off of the last full nights rest – 16 hours awake/ 8 hours asleep – Naps improve wakefulness but do not reset Sleep Propensitys cumulative effect!
Adjusting Sleep Propensity Lengthening the Sleep/Wake Cycle – 28 hour day (Westbound travel) Greatest need for sleep at 20 hours Shortening the Sleep/Wake Cycle – 20 hour day (Eastbound travel with less than 24 hours of crew rest) Greatest need for sleep at 13 hours
Performance Decrements after 16 hours and 24 hours
Sleep Inertia Definition – The grogginess that one feels after waking up from a deep sleep
Sleep Inertia In-flight Considerations – Short Naps (NASA Naps) Less than 40 minutes to stay out of Deep Sleep Effective when crew rest time is shorter – Long Naps More beneficial in reducing fatigue levels More realistic during circadian low times Afford at least 40 minutes of recovery prior to resuming flight deck duties
Crew Types and Logistics Two-Pilot Crew Augmented or Three-Pilot Crew Crew Change
Two-Pilot Crew Duty/Flight Time Limitation Considerations – Normal 14 hours duty/ 12 hours of flight (FSF, 1997) – Circadian Low *Is flight flying through or landing between the hours of 0200 - 0600 body adjusted time or duty day starts at 0400 or earlier 12 hours duty/ 10 hours of flight and consider max amount of landings (FSF, 1997)
Augmented Crews Definition Crew Bunk Categories and Considerations Circadian and Sleep Propensity Considerations
Augmented Crews Three Pilots – From original point of departure? – From intermediate and or tech stop? – Supine rest available in a separated area? 20 hours of duty (FSF, 1997) – No supine 18 hours of duty (FSF, 1997)
Crew Bunk Categories Class I – 75% sleep opportunity credit (George, 2011) Class II* – 56% sleep opportunity credit (George, 2011) Class III – 25% sleep opportunity credit (George, 2011) * Business Jet with separated crew rest facilities
Crew Change Logistics Location! – Available Resources i.e. pilots? – Great Circle? – Airline Service for preposition? – Cost? – Time to get there? – Weather? – Handling?
Fatigue Study Overview Assumptions Limitations Methodology Treatment of Data Results Conclusion
Overview Background – Fatigue Management Program for our SMS – Justify or refute our current policies Geographic Representation – Europe, Asia, South America Participants – Pilots and Flight Engineers
Hypothesis Three-Pilot Crews are less tired than Two- Pilot Crews during the last two hours of a flight to include top-of-descent, approach, landing, and post-flight
Assumptions All participants were operating during or through their circadian low All pilots afforded supine rest Two-Pilot Crews – Two pilots and one Flight Engineer – Flight Engineer data from augmented flights considered two-pilot crew Three-Pilot Crews – Three pilots from original point of departure
Limitations Human Factors – Health, emotional stability, family life, quality of sleep, alcohol/substance abuse Meteorological – Day, Night In-flight Conditions – Turbulence, Convective Weather
Summary Three-pilot crews are less tired than two- pilot crews on extended circadian low flights! Sleep propensity needs to be considered when augmenting Have a plan! – Rostering – In-flight fatigue countermeasures Learn from your Experiences
References Billiard, M, & Kent, A. (2003). Sleep: physiology, investigations, and medicine. New York, NY: Kluwer Academic/Plenum Caldwell, John A., & Caldwell, J. Lynn (2003). Fatigue in Aviation: A Guide to Staying Awake at the Stick. Burlington, VT: Ashgate Publishing Limited CEriksen, C.A., Torbjorn, E., & Nilsson, J.P. (2006). Fatigue in trans-atlantic airlineoperations: Diaries and actigraphy for two- vs. three-pilot crews. Aviation, Space, and Environmental Medicine, 77(6), 605-612. Gander, P.H., Gregory, B.S., Miller, D.L., Graebner, R.C., Connell, L.J., & Rosekind, R. (1998). Flight crew fatigue V: Long-haul air transport operations. Aviation, Space, and Environmental Medicine, 69(9), B37-B48 Gander, P.H., Rosekind, M.R., & Gregory, K.B. (1998). Flight crew fatigue VI: A synthesis. Aviation, Space, and Environmental Medicine, 69(9), B49-B60. George, F. (2011, February). Fatigue risk management. Business & Commercial Aviation, 32-37. Miller, J. C. (2005, May). Operational Risk Management of Fatigue Effects (AFRL-HE-BR-TR-2005-0073). : United State Air Force Research Lab. Neri, D., Oyung, R., Colletti, L., Mallis, M., Tam, D., & Dinges, D. (2002), Controlled Breaks as a Fatigue Countermeasure on the Flight Deck. Aviation, Space, and Environmental Medicine, 73(7) United Kingdom Civil Aviation Authority (CAA), Safety Regulation Group. (2007). Aircrew fatigue: A review of research undertaken on behalf of the UK Civil Aviation Authority (CAA PAPER 2005/04). Retrieved from http://www.caa.co.ukhttp://www.caa.co.uk
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