FatigueFatigue

AS 408 AS 408 Flight SafetyFlight Safety

Erran SweeneyErran Sweeney

FatigueFatigue

What is it?What is it? What is the FAA definition?What is the FAA definition? What causes it?What causes it? What are the symptoms?What are the symptoms? What are the consequences?What are the consequences?

Webster’s DictionaryWebster’s Dictionary

fa-tigue (ffa-tigue (fə tegə teg΄́), n., adj., v., --tigued, --), n., adj., v., --tigued, --ti-guing. --n.ti-guing. --n.

1. weariness from bodily or mental 1. weariness from bodily or mental exertion exertion

The FAA’s Take:The FAA’s Take:“one of the most treacherous “one of the most treacherous hazards to flight safety”hazards to flight safety”

AcuteAcute ChronicChronic

Riddle’s TakeRiddle’s Take

Acute

Chronic

CausesCauses

Lack of restful sleepLack of restful sleep DehydrationDehydration Noise and vibrationNoise and vibration IllnessIllness

Strenuous activityStrenuous activity HypoxiaHypoxia Boredom Boredom Unresolved stressUnresolved stress

SleepSleep

Four basic stagesFour basic stages REM sleepREM sleep Quality vs. quantityQuality vs. quantity

Stage 1Stage 1

Time between wakefulness and Time between wakefulness and drowsinessdrowsiness

Brain waves slow down as body relaxesBrain waves slow down as body relaxes Body temp., respiration and pulse slowBody temp., respiration and pulse slow Sleeper is easily awakenedSleeper is easily awakened Lasts 1 – 10 minutesLasts 1 – 10 minutes

Stage 2Stage 2

Brain activity increases slightlyBrain activity increases slightly Body relaxes further as functions slowBody relaxes further as functions slow Breathing becomes slow and steadyBreathing becomes slow and steady Sleeper is easily awakened (but may Sleeper is easily awakened (but may

deny having been asleep)deny having been asleep) Lasts about 10 minutesLasts about 10 minutes

Stage 3Stage 3

Body is almost totally at restBody is almost totally at rest Respiration and pulse very slowRespiration and pulse very slow Sleeper is difficult to awakenSleeper is difficult to awaken Considered transitional phase Considered transitional phase Lasts about 5 minutesLasts about 5 minutes

Stage 4Stage 4

Body is completely relaxedBody is completely relaxed Brain activity very slowBrain activity very slow Appears similar to unconsciousnessAppears similar to unconsciousness Sleeper is very difficult to awakenSleeper is very difficult to awaken Lasts between 30 – 45 minutesLasts between 30 – 45 minutes

REM sleepREM sleep

Characterized by rapid eye movementsCharacterized by rapid eye movements Pulse and blood pressure fluctuatePulse and blood pressure fluctuate Muscles may start to twitchMuscles may start to twitch Signifies shallowing of sleep cycle as Signifies shallowing of sleep cycle as

sleeper returns to Stage 1sleeper returns to Stage 1 Starts at 60 minutes into sleep cycle, can Starts at 60 minutes into sleep cycle, can

last 10 – 30 minuteslast 10 – 30 minutes

The power napThe power nap

The power napThe power nap

Stages 1 & 2, (1 – 25 minutes) Stages 1 & 2, (1 – 25 minutes)

Sleeper awakens easily, feels Sleeper awakens easily, feels refreshedrefreshed

Stages 3 & 4, (25 – 60 minutes)Stages 3 & 4, (25 – 60 minutes)

Sleeper hard to rouse, wakes Sleeper hard to rouse, wakes feeling groggy or more sleepyfeeling groggy or more sleepy

Fatigue SymptomsFatigue Symptoms

Feeling of Feeling of indifferenceindifference

Increased reaction Increased reaction timetime

Inability to multi-taskInability to multi-task FixationFixation Short-term memory Short-term memory

lossloss

Impaired judgmentImpaired judgment Poor decision makingPoor decision making Being easily Being easily

distracteddistracted Loss of initiativeLoss of initiative Decreased visual Decreased visual

perceptionperception

FAR 121.471FAR 121.471

““Flight time limitations and rest Flight time limitations and rest requirements: All flight crewmembers”requirements: All flight crewmembers”

Limits total hours, by time periodLimits total hours, by time period Stipulates required rest periodsStipulates required rest periods Defines “rest”Defines “rest” Originally based onOriginally based on scheduledscheduled time, time,

The Whitlow LetterThe Whitlow Letter

November 2000November 2000 Interpreted by FAA Deputy Chief Counsel Interpreted by FAA Deputy Chief Counsel

James WhitlowJames Whitlow Now requires 8 hour “look-back” restNow requires 8 hour “look-back” rest If not, flight If not, flight may not departmay not depart

ConsequencesConsequences

Case in point: Capt. Don Simonds vs. Case in point: Capt. Don Simonds vs. Pan American AirwaysPan American Airways

Jan 3, 2001 – Capt. refuses flight based Jan 3, 2001 – Capt. refuses flight based on FAR 121.471(b)on FAR 121.471(b)

Summarily fired for insubordinationSummarily fired for insubordination Failed to follow company’s “fly now, Failed to follow company’s “fly now,

grieve later” policygrieve later” policy

ConsequencesConsequences

Go! Airlines, Feb. 13, 2008•30 minute flight•Out of ATC contact, 25 minutes•Overshot Hilo by 15 miles

ConsequencesConsequences

Source: PPDRDG

ConclusionConclusion

Fatigue is a human factor…Fatigue is a human factor… It does not discriminate…It does not discriminate…

It CAN happen to you!It CAN happen to you!

ReferencesReferences

ABC News, “Two Sleeping Pilots, One Plane?”ABC News, “Two Sleeping Pilots, One Plane?” Air Safety Link, “Court Upholds ‘Whitlow Letter’ 16-hour Duty Limit”Air Safety Link, “Court Upholds ‘Whitlow Letter’ 16-hour Duty Limit” ALPA, ALPA, www.alpa.orgwww.alpa.org, “ALPA Wins Court Reinstatement of Pilot Terminated for , “ALPA Wins Court Reinstatement of Pilot Terminated for

Following FAA Rules on Rest Requirements”Following FAA Rules on Rest Requirements” Basic Flight PhysiologyBasic Flight Physiology, Third Edition, Reinhart, Dr. Richard O.,, Third Edition, Reinhart, Dr. Richard O., 14 CFR 121.47114 CFR 121.471 The Provisional Peoples’ Democratic Republic of Diego Garcia, The Provisional Peoples’ Democratic Republic of Diego Garcia,

www.zianet.com/tedmorris/dg/links.htmlwww.zianet.com/tedmorris/dg/links.html