"Effective Crew Scheduling Strategies on Ultra-long Range Flights." John R Fare.
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Transcript of "Effective Crew Scheduling Strategies on Ultra-long Range Flights." John R Fare.
"Effective Crew Scheduling Strategies on Ultra-long Range Flights."
John R Fare
Introduction
• Current and Future Demands of our Customers – Longer range Aircraft– Faster Speeds– Shorter Layovers
Alertness in the Aircraft
• Three Distinct Factors that Determine Cockpit Alertness– Circadian Rhythm– Sleep Propensity/Pressure– Sleep Inertia
Circadian Rhythm
• Reason – Regulate bodily functions
• Synchronization– Length• 25.3 hours
– Zeitgebers “time keepers”• 24 hours
– Low• 0200-0600 and 1500-1700
Circadian Rhythm (cont.)
Circadian Adjustment
• Phase Advance• Phase Delay• Resynchronization
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• Adjusting• Performance Decrements
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 Propensity’s cumulative effect!
Sleep Propensity/Pressure (cont.)
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• In-flight Considerations
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• Circadian Considerations
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
Methodology
Stanford Sleepiness Scale (SSS)
Treatment of Data
• All Duty Start Times Adjusted to “Body Adjusted Time”– Eastbound• 57 minutes per day
–Westbound• 90 minutes per day
Results
• SSS Mean for the Last Two Hours of Duty
• Crewing Technique vs. SSS• SSS Mean for Entire Flight vs. Start
Time of Duty Day• Crew Rest Sleep Percentages vs.
Duty Hour
SSS Mean for the Last Two Hours of Duty
2 Pilot 3 Pilot2.05
2.1
2.15
2.2
2.25
2.3
2.35
2.4
2.45
SSS During Last 2 Hours of Duty
Hour 1Hour2
Conclusion
• Three-Pilot Flight Crews are Less Tired than Two-Pilot Crews
Crewing Technique vs. SSS
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 200
0.5
1
1.5
2
2.5
3
3.5
4
Crewing Technique vs. SSS
2 Pilot3 Pilot
Conclusion
• SSS Levels Separate at Duty Hour 11/ Flight Hour 9
• Johnson & Johnson Aviation Lowered its Circadian Low Duty Limits to 9 Hours of Flight with a Max of 2 Landings
SSS Mean for Entire Flight vs. Start Time of Duty Day
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 240
0.5
1
1.5
2
2.5
3
SSS vs. Adjusted Start of Duty Day
SSS
Conclusion
• Start time does correlate to SSS levels of augmented crews
• There is a significant increase in SSS with start times between 1800 and 0700
Crew Rest Sleep Percentages vs. Duty Hour
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 190
20
40
60
80
100
120
SleepAwake
Conclusions
• Physiological need determines success
• Most sleep attained between duty hour 9 and 18
• Strategic “rostering” – PF gets the most consideration
Practical Approaches
• Two Pilots – KTEB – LFPB – KTEB –Minimum Layover– Off Duty Prior to Circadian Low
• Three Pilots– KTEB – RJTT– Fuel Stop in PANC
Europe “Quickturn”
• Two Pilots–Depart KTEB @ 1800 Local–Arrive LFPB @ 0630 Local• 10 hour rest period + 2 hours for travel and “unwinding”
–Depart LFPB @ 1830 Local–Arrive KTEB @ 2030 Local
Three Pilots to Tokyo
• Three Pilots – Depart KTEB @ 0800 Local– Arrive RJTT @ 1300 Local the next day
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
ReferencesBilliard, 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 LimitedCEriksen, C.A., Torbjorn, E., & Nilsson, J.P. (2006). Fatigue in trans-atlantic airline
operations: 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-B48Gander, 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.uk