SCIENCE IN AN OPERATIONAL SETTING Philippa Gander Sleep/Wake - - PowerPoint PPT Presentation

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Philippa Gander Sleep/Wake Research Centre, Massey University Jim Mangie Delta Air Lines

SCIENCE IN AN OPERATIONAL SETTING

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Outline

• What to measure
• When to measure
• Interpreting the data
• Safety Performance Indicators
• Conclusions

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

What to Measure: Crew Fatigue

ICAO definition of fatigue:

A physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase, or workload (mental and/or physical activity) that can impair a crew member’s alertness and ability to safely operate an aircraft or perform safety related duties.

• Functional status (subjective ,objective)
• Sleep history
• Circadian phase
• Workload

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Sleep: Actigraphy and Diaries

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

When to Measure Crew Fatigue

• Monitoring for FRM Processes
• In response to a series of fatigue reports
• to identify extent and severity of hazard
• In response to an incident
• SPIs to evaluate effectiveness of fatigue mitigations and

controls

• Validation of a new route
• Monitoring for FRMS Assurance Processes
• SPIs set in FRMS Policy objectives
• SPIs for regulatory audit

Crew fatigue measures may not always be needed

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Safety Performance Indicators (SPIs)

5 FRMS Components

Fatigue Safety Action Group

• 3. Risk Management

Processes

• 1. Policy

4.Safety Assurance Processes

• 5. Promotion

Processes

• 2. Documentation

SMS

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Comparing fatigue on ULR and LR flights

Safety Performance Indicators: Example

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2 4 6 8 10 12 Median sleep (hrs) 24 hrs prior to duty Landing Relief

Fatigue Status at Start of Duty

SPI – sleep in the last 24 hrs

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

2 2.5 3 3.5 4 4.5 5 mean PVT reaction speed Landing Relief

Fatigue Status at Start of Duty

SPI – mean PVT reaction speed early in flight

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

0.5 1 1.5 2 2.5 3 3.5 4 4.5 Median sleep in flight (hrs) Landing Relief

Fatigue Status at Top of Descent

SPI – median total in-flight sleep

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

2 2.5 3 3.5 4 4.5 5 mean PVT reaction speed Landing Relief

Fatigue Status at Top of Descent

SPI – mean PVT reaction speed late in flight

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

5 10 15 20 25 30 35 40 45 50 % crewmembers Landing Relief

Fatigue Status at Top of Descent

SPI – % crew with KSS ≥ 7

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Operational SPIs: Examples

• Track data on number of :
• exceedances of planned crew duty day (e.g. > 14 hrs)
• flight duty periods ending > 30 mins later than scheduled
• flight duty periods starting / ending within window of

circadian low (WOCL)

• reserve crew call-outs (on particular flights, at a particular

crew base, etc) Monitoring of FRM processes Monitoring of FRMS safety assurance processes

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Conclusions

• Challenge
• Developing in-house expertise versus using consultants ($$)
• Data sharing
• Operators don’t have to reinvent the wheel
• Rich data source for improving fatigue science
• Needs
• Paradigms for data sharing
• Better indicators of fatigue-related performance impairment
• Better fatigue measurement technologies
• Better fatigue risk assessment (safety consequences of

being fatigued in a given context)

• Better fatigue risk controls and mitigations

Cooperation is the key

SLEEP/WAKE Research Centre MOE TIKA/MOE PAI

Acknowledgements

• Dr Jarnail Singh, CAA of Singapore
• Participants in B-777 study
• Delta data collection team
• Scientific Steering Committee, FAA 3-airline

study

• Margo van den Berg, Dr Leigh Signal, Dr

Sarah Jay, Sleep/Wake Research Centre