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