tell two stories fatigue – definition and effects some operationally significant aspects of...

• Tell two stories• Fatigue – definition and effects• Some operationally significant aspects of

fatigue• Contribution of fatigue to risk and accidents• Practical countermeasures• CAM initiatives• An outsider’s view of FRMS

• 7 Squadron Chinook squadron operating in Kosovo

• Crew fatigued – 3 to 4 hours sleep per night for several days

• Sleeping in dilapidated buildings

• Mission behind enemy lines, high threat area

• Pilot awoke over sea at 200 feet going down

• Pulled collective up to its limit for first time in pilot’s career

• Near CFIT

Definition:• Subjective feeling of tiredness, lethargy,

lack of motivation• Objective performance decrements

Definition:• Subjective feeling of tiredness, lethargy,

lack of motivation• Objective performance decrements

People are not good at assessing their own performance decrement

Van Dongen et al in Sleep 2003 (from Caldwell)

Performance Deficit

Performance Deficit

Self-Rated SleepinessSelf-Rated Sleepiness

Definition:• Subjective feeling of tiredness, lethargy,

lack of motivation• Objective performance decrements

Caused by:• Sleep loss• Work load• Time of day (circadian rhythm status)

Susceptibility to fatigue varies greatly• Levels of performance deficit can vary

ten fold with equal amounts of sleep deprivation

• Resistant and susceptible people report the same amount of sleepiness

• Need same amount of sleep• A schedule to suit fatigue resistant

people can result in dangerous levels of fatigue in others

Caldwell et al (2005) Behavioral Neuroscience 119 694-707

US Navy recruit training camp•Mean age 18 (17-34)•Eight week course•Intense academic and physical regimen •Traditionally 6 hours sleep per night

J. Lamb PhD, USN Naval Submarine Research Laboratory

• Changed to 8 hours per night in 2002

• Highly significant increase in examination scores

• Attrition halved

• Sick call decreased 70%

J. Lamb PhD, USN Naval Submarine Research Laboratory

• Does resistance to fatigue make selection for senior rank more likely?

• Mood changes: irritability, decreased cooperation

• Unconscious acceptance of lower personal standards

• Decreased ability to sustain attention– Increased errors

• Decreased number of items which a person can keep in mind at one time

• Leading to diminished situational awareness, “tunnel vision”

• Procedural, rule-based activities most resistant to fatigue

• Those requiring creative thinking more vulnerable– Failure to appreciate that the situation is

changing– Difficulty generating new options– Tendency to revert to “tired and true”

solutions not appropriate to current situation

• The wrong question - reactive• The right question - proactive - “What

can we due to reduce the risk of having an accident?”

• Fatigue very often present in military flying– Often contributes to accidents– Rarely a sole cause– Reducing fatigue reduces risk

• 4 of 8 recent rotary accidents – fatigue major contributaaaing factor

• Evaluation of C-17 and Tristar workload revealed significant risk due to fatigue

Jeffrey H. Goode, Journal of Safety Research 2003

Accidents vs Exposure

00.5

11.5

2

2.53

3.54

4.5

1 - 3 4 - 6 7 - 9 10 - 12 > 13

Captain Duty Hours

Acci

dent

Inde

x

Factors increasing mission risk:

Factors increasing mission risk:• Varying skill of the handling pilot• Quality of crew coordination• Pressure: time, demands of “customers”• Nature of landing site: topography,

amount of dust, light, etc• Fatigue• Concern re enemy threats• Many others

“You shall not needlessly fatigue your troops.”

• Failure to appreciate that the situation is changing

“Personally, I think people hear all too often of outstanding leaders such as McChrystal and Petraeus and how they don’t sleep, and it appears to become normalized to work a 16-20 hour day in command during crisis.”

• Caffeine

• Temazepam

• Modafinil

• Much greater awareness of fatigue among leaders

• “Duty Holder” initiative• “It depends on the Captain”

• Planned in-flight napping

• Augmented crews

• Improvements in accommodation, scheduling practices

• Establish an RAF medical officer appointment to provide advice regarding fatigue to military aviators

• Operational Event Analysis – three in progress looking at all human factors aspects of operating specific airframes

• Ongoing collaboration with fatigue authorities at QinetiQ

CAM teaching staff station visits

CAM teaching staff station visits•Coningsby, Leuchars, Odiham, Valley, Yeovilton, Lakenheath

CAM teaching staff station visits•Coningsby, Leuchars, Odiham, Valley, Yeovilton, Lakenheath•In near future Linton-on-Ouse and Brize Norton

CAM teaching staff station visits•Coningsby, Leuchars, Odiham, Valley, Yeovilton, Lakenheath•In near future Linton-on-Ouse and Brize Norton•Visits will continue

Provide presentations regarding fatigue to:• Ab initio, OCU, and refresher students

(RAF, RN)• New military aviation medicine doctors • MAA Flying Supervisors’ Courses and

Flight Safety Officers’ Courses• Ad hoc fatigue presentations to aviators

and maintenance personnel at RAF and RN flying stations – eg Flight Safety Days, RN Senior Officer Symposium

• Fatigue increases risks of mission failure and/or accidents

• Awareness through education can decrease risk

• Local management of fatigue is required

• Consideration of small changes in accommodation, scheduling can greatly reduce fatigue