RAA Convention Fatigue Science Initiatives Capt. Kevin Hiatt Dr. Hans Van Dongen www.flightsafety.org 1
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Fatigue Science Initiatives Issues & Questions Colgan Accident - Pivotal Event Actions - Global Issue, Symposiums, Studies, Articles Emerging Questions - Multi Segment Ops/Workload Independent Study - Research/Study to Address Gaps Washington State University Dr. Hans Van Dongen www.flightsafety.org 7
Fatigue Science Initiatives Hans Van Dongen, Ph.D. Research Professor
Fatigue is Determined by Sleep/Wake History (Time Awake) and Circadian Rhythm (Time of Day) Prior sleep and wakefulness + Time of day Activation Activation Alertness/ fatigue Alertness Daytime duty hours
Fatigue is Determined by Sleep/Wake History (Time Awake) and Circadian Rhythm (Time of Day): Nighttime Duty Prior sleep and wakefulness + Time of day Activation Activation Alertness/ fatigue Alertness Nighttime duty hours
Fatigue Risk Management: a Commitment to Safety Reason s Swiss Cheese Model of Accident Causation
Context for Fatigue Science in Operational Settings: Neurobiological and Operational Factors for Fatigue countermeasures duty hours (timing & duration) relative risk of errors, incidents and accidents modulators in the environment weather, sea state, distractions, illness, work demands, etc. (mostly transient) light instability time on task ~ sleep inertia fatigue (cognitive impairment) Neurobiological comes with the individual Operational comes with the task at hand
Table B to 14 CFR Part 117 Flight Duty Period: Unaugmented Operations Part 117 regulates flight duty period, and by extension time awake, as a function of time of day, in accordance with sleep science. Part 117 also regulates flight duty period as a function of number of flight segments (i.e., workload), but without scientific basis. 2010: the WSU RAA Pilot Fatigue Study set out to fill this science gap.
Effect of Workload on Fatigue during Sleep Deprivation Workload: high (2 nd ½) high (1 st ½) moderate Psychomotor Vigilance Task (PVT)
WSU RAA Fatigue Study, Phase I: Development of a Mathematical Fatigue Model That Accounts for Workload increasing fatigue equilibrium scheduled sleep pre/post-flight take-off en-route landing
Comparing FAA s 2010 Notice of Proposed Rule Making to Earlier ARC Recommendations FAA: 9.5 h duty Start 05:00, 6 segments ARC: 11 h duty increasing fatigue
RAA s Comments to Notice of Proposed Rule Making Time of Start (Home Base) 1 Flight Segment 2 3 4 5 6 7+ 0000-0059 0100-0159 0200-0259 10 (9) 10 (9) 10 (9) 10 (9) 0300-0359 10 (9) 10 (9) 10 (9) 10 (9) 0400-0459 10 (9) 10 (9) 0500-0559 12 (11) 12 (11) 12 (11) 12 (11) 11.5 (10) 11 (9.5) 10.5 (9) 0600-0659 0700-0759 11.5 (11) 0800-0859 11.5 (11) 0900-0959 11.5 (11) 1000-1059 11.5 (11) 1100-1159 11.5 (11) 1200-1259 11.5 (11) Important caveat: these results were preliminary in nature, by design, as the Phase I fatigue model was yet to be operationally validated. The WSU RAA Fatigue Study, Phase II sought to validate the fatigue model of Phase I for multi-segment operations.
WSU RAA Fatigue Study, Phase II: Simulator Study Scientific Steering Committee 2 independent scientists 3 representatives of Air Wisconsin 3 ARW MEC and ALPA representatives 1 representative of the RAA
Flight Simulator Study Design and Participants The simulator study involved a 4-day pairing. Days 2 and 3 were simulator days, each with a 9-hour duty period, flown like revenue flights. Day 1: following a rest day, deadhead to simulator location (CLT) and meet at crew hotel for briefing at 17:00. Day 2: fly multi-segment or single-segment simulator scenario. Day 3: fly single-segment or multi-segment simulator scenario. Day 4: deadhead back to domicile. Study volunteers were 24 active-duty pilots (12 Capt, 12 FO), randomly selected from among Air Wisconsin lineholders. Flight Experience (hours) 12,000 10,000 8,000 6,000 4,000 2,000 0 CRJ-200 Capt FO Capt FO
Schematic of the Two Simulator Trips Flown by Each Crew plane swap STL SPI SPI DFW DFW CRP CRP IAH IAH LIT 5 6 7 8 9 10 11 12 13 14 15 Time of Day (hours) MIA SEA Duty Period (9 hours) Psychomotor Vigilance Task (PVT) testing reaction time (ms) reaction time (ms) 2000 1500 1000 500 0 0 60 120 180 240 300 360 420 480 540 600 53 h awake (13:00) time on task (s) 0 60 120 180 240 300 360 420 480 540 600 time on task (s) time on task (s)
Fatiguing Effect of Multi-Segment Duty Day as Compared to Single-Segment Duty Day: Model Validation (Preliminary) 1.6 Observed Predicted 1.2 0.8 Relative Fatigue 0.4 0.0-0.4 F 1,8 =21.7 P=0.002 RMSE=0.24 R 2 =73.1% -0.8 5 6 7 8 9 10 11 12 13 14 15 Time of Day (hours) Duty Period (9 hours)
WSU RAA Fatigue Study, Phase III: Fatigue Risk Management Systems and Model-Based Fatigue Risk Management Alertness SAFTE/FAST (% effectiveness) % efficiency 100 90 80 70 60 LR Predicted Predicted Fatigue fatigue in in Hour hour of of arrival Arrival ULR 50 11.0 12.0 13.0 14.0 15.0 16.0 17.0 Scheduled flight duration
The Future of Model-Based Fatigue Risk Management? computer optimization duty hour guidelines personnel characteristics and qualifications personnel availability resource availability schedule redundancy needed for robustness other operational constraints possible duty schedules efficiency cost fatigue other relevant outcomes model-based fatigue predictions duty schedules and rosters
Acknowledgments Air Wisconsin Airline Corporation Air Wisconsin Pilots, ARW MEC, and ALPA National CAE (CRJ-200 flight simulator) SSC: Dr. Lynn Caldwell (US Navy, independent scientist), Dr. Peter Demitry (ALPA, scientific consultant), Bob Frisch (Air Wisconsin, VP Flight Ops), Richard Swindell (ARC MEC, Chairman), Ryan Gibson (Air Wisconsin, Regional Chief Pilot), Matthew Hintze (ARW MEC), Paul Preidecker (Air Wisconsin, Chief Flight Instructor), Scott Foose (RAA, SrVP), and Dr. Hans Van Dongen (WSU, principal investigator) Study execution committee: Ryan Gibson, Matthew Hintze, Paul Preidecker, Sandy Pierson, and many Air Wisconsin employees working in the background Simulator instructors: Jason Weirick and Judd Brinkman WSU research assistants: Kimberly Honn and Brieann Satterfield WSU fatigue modeler: Peter McCauley Regional Airline Association