Operational Excellence

The Impact ofThe Impact ofFatigue on PerformanceFatigue on Performance

CDR Walt “Lunar” DalitschCDR Walt “Lunar” DalitschSenior Aerospace Medicine Specialist, Branch Clinic, NAS North IslandSenior Aerospace Medicine Specialist, Branch Clinic, NAS North Island

Deputy Specialty Leader, Aerospace MedicineDeputy Specialty Leader, Aerospace Medicine

776 aircraftdestroyed in

1954

USN/USMC, FY50-06

Class A Mishap RateFY02: 2.28FY03: 2.44FY04: 2.14FY05: 1.84FY06: 1.50

Class A Mishap RateFY02: 2.28FY03: 2.44FY04: 2.14FY05: 1.84FY06: 1.50

Naval Aviation Mishap HistoryNaval Aviation Mishap History

200334 lives lost

38 a/c destroyed

200419 lives lost

33 a/c destroyed

NSC Data: Oct ’06

200540 lives lost

23 a/c destroyed

Parents married, 1966Doc born, 1967

Drives first tractor, 1971First French kiss, 1973

M.D., 1993Wings of Gold, 1995

Grandparents celebrate 10th anniversary, 1950

Father graduates high school, 1956

“The Lost Years” SAS, 2008

Where am I from?Where am I from?

Background Background

• VP-11VP-11

• VP-10VP-10

• VMFA-312VMFA-312

• CVW-3 and the Big “E” (CVN 65)CVW-3 and the Big “E” (CVN 65)

• MAG-36MAG-36

• MPH & RAM programMPH & RAM program

• Senior Medical Officer on the IKE (CVN 69)Senior Medical Officer on the IKE (CVN 69)

• ““Public Health Guy” – Naples, ItalyPublic Health Guy” – Naples, Italy

• School of Aviation Safety, NASCSchool of Aviation Safety, NASC

• Force Surgeon, CNAPForce Surgeon, CNAP

27 Military Aircraft Flown27 Military Aircraft Flown

T-34C T-34C MentorMentor

TH-57C TH-57C Jet RangerJet Ranger

P-3C P-3C OrionOrion

MR-2 MR-2 NimrodNimrod

F/A-18B & D F/A-18B & D HornetHornet

E-2C E-2C HawkeyeHawkeye

H-60 H-60 SeahawkSeahawk

C-20G C-20G Gulfstream IVGulfstream IV

T-39 T-39 SabrelinerSabreliner

C-26B C-26B MetrolinerMetroliner

C-144 C-144 Ocean SentryOcean Sentry

HH-65 HH-65 DolphinDolphin

HU-25 HU-25 FalconFalcon

T-1 T-1 JayhawkJayhawk

C-12 C-12 HuronHuron

T-6A T-6A Texan IITexan II

C-40 C-40 ClipperClipper

E-6B E-6B MercuryMercury

EA-6B EA-6B ProwlerProwler

S-3B S-3B VikingViking

ES-3B ES-3B ShadowShadow

C-2 C-2 GreyhoundGreyhound

CH-53 CH-53 Sea StallionSea Stallion

CH-46 CH-46 Sea KnightSea Knight

C-130 C-130 HerculesHercules

UH-3H UH-3H Sea KingSea King

C-9B C-9B Skytrain IISkytrain II

““The mechanization of modern war has The mechanization of modern war has produced a chain of health problems. produced a chain of health problems. One One of the greatest of these is fatigueof the greatest of these is fatigue. In the . In the complicated meshwork of speed and complicated meshwork of speed and change, many factors make for fatigue. change, many factors make for fatigue. Scarcely any key man in modern war is Scarcely any key man in modern war is more subjectmore subject to stress and strain, to to stress and strain, to demands on his body and mind making for demands on his body and mind making for fatigue, fatigue, than the military pilotthan the military pilot.”.”

– – Dr. Martyn Kafka, 1942.Dr. Martyn Kafka, 1942.

Kafka, M. Martyn. Kafka, M. Martyn. Flying HealthFlying Health. Harrisburg, PA: Military Service Publishing Company, 1942.. Harrisburg, PA: Military Service Publishing Company, 1942.

Approach into Diego GarciaApproach into Diego Garcia2000 local time2000 local time

1800

X

DH 209’

IAF2000

10 nm 7 nm 6 nm

level/slow <215 knots

Flaps 40%Gear down121 knots

Proper flight path

Courtesy Armentrout JG, et. al.

Actual flight path

IMC

AltitudeAirspeed Att Gyro Heading

Thr

ottl

es

AOA

Fla

ps

Scenario 1Scenario 1

““Sir, I’m good to go, I’m just Sir, I’m good to go, I’m just a little tired…”a little tired…”

Scenario 2Scenario 2

““Sir, I’m good to go, I’m just Sir, I’m good to go, I’m just a little drunk…”a little drunk…”

Do you feel yourself wanting to Do you feel yourself wanting to doze after lunch?doze after lunch?

Do you fall asleep within ten Do you fall asleep within ten minutes after lights out?minutes after lights out?

Do you sleep more on weekends Do you sleep more on weekends than during the week?than during the week?

Do you sleep more on vacation Do you sleep more on vacation than when you are working?than when you are working?

52 recognized cases

The BrainThe Brain

• StructureStructure• Massively parallelMassively parallel• ElectrochemicalElectrochemical• Digital computerDigital computer

• Fuel: Fuel: oxygenoxygen & & glucoseglucose • 2% of body mass2% of body mass• 25% of resting energy use25% of resting energy use

• All other systems exist to All other systems exist to support the brainsupport the brain

CommunicationCommunication

• NeuronsNeurons• About 100 billionAbout 100 billion• WiresWires

• SynapsesSynapses• TrillionsTrillions• Logic gatesLogic gates

http://www.pfizer.com/brain/images/neuron_large.gif

The Science of FatigueThe Science of Fatigue

• The brain:The brain:• Cannot run continuously awake Cannot run continuously awake • Requires scheduled recharge & Requires scheduled recharge &

maintenancemaintenance• Accumulates “fatigue” when operatingAccumulates “fatigue” when operating

• Fatigue is a genetic, physiologic stateFatigue is a genetic, physiologic state• Not due to rank, rate, experience, Not due to rank, rate, experience,

motivation, or attitudemotivation, or attitude

How Much Sleep Do You Need?How Much Sleep Do You Need?

4 5 6 7 8 9 10 11 12

Old-thinking

New-thinking

““Humans are the only animals that Humans are the only animals that willingly deprive themselves of willingly deprive themselves of sleep.”sleep.”

–– Eve Van CauterEve Van Cauter

Sleep researcherSleep researcher

University of Chicago University of Chicago

• Truck accidents 30-40% by NTSBTruck accidents 30-40% by NTSB

• Daylight Savings Time: +8%, -9%Daylight Savings Time: +8%, -9%

• Challenger, Exxon Valdez, Challenger, Exxon Valdez, Chernobyl, Three Mile Island, Chernobyl, Three Mile Island, Roosevelt-Leyte Gulf?Roosevelt-Leyte Gulf?

The Problem:The Problem:Performance DegradationPerformance Degradation

Performance plummets

after 15 hours awake

Equivalent to BAC of

0.08 after 22 hours awake

Signs and Symptoms of FatigueSigns and Symptoms of Fatigue

• Irritability, mood Irritability, mood deterioration, deterioration, reduced patiencereduced patience

• Impaired Impaired communicationcommunication

• Reduced vigilance, Reduced vigilance, inattentioninattention

• Task fixationTask fixation• Tolerance for error Tolerance for error

and riskand risk

• Complex reasoning Complex reasoning & decision making & decision making

• Conservation of Conservation of effort, reduced effort, reduced motivationmotivation

• ForgetfulnessForgetfulness• Increased reaction Increased reaction

times times • Lapses and Lapses and

“microsleeps”“microsleeps”

Decision Making

Adaptability; Flexibility

Communication

Assertiveness

Mission Analysis

Leadership

Situational Awareness

Threat & Error

Management

Microsleeps in a Taxi DriverMicrosleeps in a Taxi Driver

Microsleeps in Military SecurityMicrosleeps in Military Security

Velocity: 14 mph

Roosevelt - Leyte GulfRoosevelt - Leyte GulfMB Findings:MB Findings:

HUMAN ERROR: “HUMAN ERROR: “CVN OOD:CVN OOD:• ... in disregard of nautical rules ... in disregard of nautical rules

of the road...”of the road...”• ...unable to recognize or ...unable to recognize or

unwilling to act....”unwilling to act....”• ...without communicating ...without communicating

intent. “intent. “• ...did not act with appropriate ...did not act with appropriate

dispatch...”dispatch...”• ...did not advise CO that ...”...did not advise CO that ...”• ...did not advise CO of ...did not advise CO of

conflicting concurrent conflicting concurrent events...”events...”

• ...did not advise CG in a timely ...did not advise CG in a timely manner..., manner...,

• ... failed to sense the urgency ... failed to sense the urgency of...”of...”

• ...did not notify the CO...”...did not notify the CO...”• ...became overly involved in ...became overly involved in

managing...”managing...”

HUMAN ERROR: “HUMAN ERROR: “CG CO:CG CO:• ... failed to recognize the ... failed to recognize the

seriousness...”seriousness...”HUMAN ERROR: “HUMAN ERROR: “CG XO:CG XO:

• ...failed to properly analyze the ...failed to properly analyze the movements of...”movements of...”

• ...failure to consider the possibility ...failure to consider the possibility of ...”of ...”

HUMAN ERROR: “HUMAN ERROR: “CG OOD:CG OOD:• ...failed to properly analyze the ...failed to properly analyze the

movements of...”movements of...”• ...was not proactive ... in ...was not proactive ... in

communications, ...was focused communications, ...was focused on...”on...”

• ...failed to demand proper support ...failed to demand proper support from ...”from ...”

• ...failed to prioritize bridge duties...”...failed to prioritize bridge duties...”HUMAN ERROR: “HUMAN ERROR: “CG TAO:CG TAO:

• ...focused on the ... scenario, failed ...focused on the ... scenario, failed to supervise, ... did not to supervise, ... did not recognize,...”recognize,...”

Brain FunctionsBrain Functions

• Mood, personalityMood, personality• Problem-solvingProblem-solving• High-level High-level

reasoningreasoning• Body sense and Body sense and

MovementMovement• MemoryMemory• SpeechSpeech• VisionVision• Balance & Balance &

CoordinationCoordination• ConsciousnessConsciousness• BreathingBreathing• Heart rateHeart rate

WRAIR Restricted Sleep Study:WRAIR Restricted Sleep Study:Adaptation to Chronic Sleep RestrictionAdaptation to Chronic Sleep Restriction

50

65

80

95

110

0 T1 T2 B 1 2 3 4 5 6 7 R1 R2 R3Day

Mea

n S

pee

d o

n P

sych

om

oto

r V

igila

nce

Tas

k(a

s a

% o

f Bas

elin

e)

9 Hr

7 Hr

5 Hr

3 Hr

SAFTE/FASTR2 = 0.94

Recovery 7 Day Restricted Sleep Baseline

50

65

80

95

110

0 T1 T2 B 1 2 3 4 5 6 7 R1 R2 R3Day

Mea

n S

pee

d o

n P

sych

om

oto

r V

igila

nce

Tas

k(a

s a

% o

f Bas

elin

e)

9 Hr

7 Hr

5 Hr

3 Hr

SAFTE/FASTR2 = 0.94

Recovery 7 Day Restricted Sleep Baseline

WRAIR Restricted Sleep Study:WRAIR Restricted Sleep Study:Adaptation to Chronic Sleep RestrictionAdaptation to Chronic Sleep Restriction

50

65

80

95

110

0 T1 T2 B 1 2 3 4 5 6 7 R1 R2 R3Day

Mea

n S

pee

d o

n P

sych

om

oto

r V

igila

nce

Tas

k(a

s a

% o

f Bas

elin

e)

9 Hr

7 Hr

5 Hr

3 Hr

SAFTE/FASTR2 = 0.94

Recovery 7 Day Restricted Sleep Baseline

WRAIR Restricted Sleep Study:WRAIR Restricted Sleep Study:Adaptation to Chronic Sleep RestrictionAdaptation to Chronic Sleep Restriction

Sleep FactsSleep Facts

• Very difficult to measureVery difficult to measure

• Self-assessment is worst approachSelf-assessment is worst approach

• ~ 2 hrs performance for each 1 hr of sleep ~ 2 hrs performance for each 1 hr of sleep

• 6 > sleep > 10 hours - higher mortality6 > sleep > 10 hours - higher mortality

• Sleep cannot be “banked,” but sleep Sleep cannot be “banked,” but sleep deficits accumulatedeficits accumulate

• Rest does not replace sleepRest does not replace sleep

Sleep ArchitectureSleep ArchitectureUltradian Cycles ~ 90 mins

MSLT AveragesMSLT Averages

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Latency in Minutes

Mean11.4

moderatemoderate sleepiness (29%) sleepiness (29%)

excessive daytimeexcessive daytime sleepiness (7.7%) sleepiness (7.7%)

0 hr TIB x 1 night

Narcolepsy

Sleepapnea

6 hr TIB x 4 nights

8 hr TIB x 5 nights

10 hr TIB x 14 nights(full alertness)

anesthesiaresidents

Adapted from Dement; Sleep Medicine

USN Recruits Test Scores by YearUSN Recruits Test Scores by Year6 vs. 8 hours sleep6 vs. 8 hours sleep

6 hr 6 hr

8 hr

Dr. Nita Miller, Research Asst. Prof., NPS

Sleep Stages vs. AgeSleep Stages vs. Age

Pilot PerformancePilot PerformanceLong Haul vs. NapsLong Haul vs. Naps

With 40 minute napWithout naps

Rosekind MR, et. al. Crew Factors in Flight Operations IX: Effects of Planned Cockpit Rest on Crew Performance and Alertness in Long-Haul Operations.

Nap RulesNap Rules

• Naps are goodNaps are good

• More naps are betterMore naps are better

• Long naps are bestLong naps are best

• Expect sleep inertiaExpect sleep inertia

Take a nap!Take a nap!

Circadian RhythmsCircadian Rhythms

The circadian “alerting” signal

The brain “energy” level

The “Circadian Cycle”The “Circadian Cycle”

Circadian RhythmsCircadian Rhythms

• Over 300 circadian rhythms (temp, Over 300 circadian rhythms (temp, pulse, immune function, hormones, etc.)pulse, immune function, hormones, etc.)

• Entrained by light, period ~24 hoursEntrained by light, period ~24 hours

• Travel across time zones requires Travel across time zones requires clocks to phase shift to new locationclocks to phase shift to new location

• Can be a week or more to normalize an Can be a week or more to normalize an external desynchronosisexternal desynchronosis

Internal SynchronosisInternal SynchronosisCore Core

temperaturetemperature

ImmuneImmunefunctionfunction

Gastric acidGastric acidsecretionsecretion

StressStresshormoneshormones

GlucoseGlucoselevellevel

MetabolicMetabolicraterate

HydrationHydration

KidneyKidneyflowflow

GutGutactivityactivity

LipidsLipids

GrowthGrowthhormonehormone

LiverLiverfunctionfunction

Recommended Fatigue Recommended Fatigue CountermeasuresCountermeasures

• Go into high OPTEMPO Go into high OPTEMPO evolutions well-restedevolutions well-rested

• Pre-plan; minimize changesPre-plan; minimize changes• Schedule with knowledge of Schedule with knowledge of

circadian effectscircadian effects• Minimize shifts > 12 hoursMinimize shifts > 12 hours• Schedule/ encourage napsSchedule/ encourage naps• Sleep etiquetteSleep etiquette• Diet/ meals and feedingDiet/ meals and feeding• Exercise and activityExercise and activity• Shift work – how to handle?Shift work – how to handle?• Who knows when to quit?Who knows when to quit?

Adjuncts Adjuncts

Stimulants Stimulants and and

SedativesSedatives

“I said, ‘One of us is hallucinating!’”

POC: Steven Hursh, PhD, Tel: 410-538-2901SAFTE Model Patent Pending55

Sleep, Activity, Fatigue and Task Effectiveness Model

COGNITIVEEFFECTIVENESS

Biomedical Modeling and Analysis Program

SLEEP “QUALITY”FRAGMENTATION

SLEEP INTENSITY

SLEEP REGULATION

SLEEP RESERVOIR

SLEEP DEBTFEEDBACK

LOOP

INERTIA

CIRCADIAN OSCILLATORS

SLEEP ACCUMULATION(Reservoir Fill)

PERFORMANCE USE(Reservoir Depletion)

DYNAMICPHASE

PERFORMANCEMODULATION

12

SAIC Proprietary

24-hourperiod

Sleep

Afternooncircadian

dipsPerformance

drop

Work

BACequivalent

scale

Day-night cycles

Night shift

Exxon Valdez – 00:15Bhopal – 01:00

Chernobyl – 01:23Kuwait H-46 Mishap – 02:33

Roosevelt Leyte Gulf – 02:52Three Mile Island – 04:00

HSL SH-60B Mishap – 05:30

The midnight to 0600 window is a very dangerous

place to do business!

Wrist Activity Monitor Wrist Activity Monitor

ActiwatchActiwatch

Dr. Nita Miller, Research Asst. Prof., NPS

• Identifies awake and sleep periods

• Records up to a year• Downloadable

Reasonably Good SleepReasonably Good Sleep

Dr. Nita Miller, Research Asst. Prof., NPS Dr. Nita Miller, Research Asst. Prof., NPS

FAST Graph: FAST Graph: USS StennisUSS Stennis # 03 # 03

Dr. Nita Miller, Research Asst. Prof., NPS Dr. Nita Miller, Research Asst. Prof., NPS

Poor SleepPoor Sleep

Dr. Nita Miller, Research Asst. Prof., NPS Dr. Nita Miller, Research Asst. Prof., NPS

FAST Graph: FAST Graph: USS StennisUSS Stennis #52 #52

Dr. Nita Miller, Research Asst. Prof., NPS Dr. Nita Miller, Research Asst. Prof., NPS

“Fatigue and Related Human Factors in the Near Crash of a Large Military Aircraft.”

Mishap TimelineMishap Timeline

• M-3 DaysM-3 Days: Crew flies from CA to Tokyo after layover: Crew flies from CA to Tokyo after layover

• M-2 DaysM-2 Days: Crew wakes mid-morning (Tokyo local : Crew wakes mid-morning (Tokyo local time); re-enters crew rest after experiencing time); re-enters crew rest after experiencing maintenance problemsmaintenance problems• 4 hr. brief +4 hr. delay +12 hrs. rest results in 20 hr. day; 4 hr. brief +4 hr. delay +12 hrs. rest results in 20 hr. day;

advances crew day by 4 hours dailyadvances crew day by 4 hours daily

• M-1 DayM-1 Day: Crew wakes between 0400-0600; re-enters : Crew wakes between 0400-0600; re-enters crew rest after experiencing additional maintenance crew rest after experiencing additional maintenance problems; most of crew does not go to sleep until problems; most of crew does not go to sleep until 2100-2300 that night2100-2300 that night

• M-22 HrsM-22 Hrs: Crew wakes at 0230: Crew wakes at 0230

• M-17 HrsM-17 Hrs: Crew takes off to Singapore at 0730; none of the : Crew takes off to Singapore at 0730; none of the pilots sleep on this legpilots sleep on this leg

• M-5 HrsM-5 Hrs: Crew departs Singapore around 1930 for Diego : Crew departs Singapore around 1930 for Diego Garcia after 5 hours on the ground; right-seat co-pilot flies Garcia after 5 hours on the ground; right-seat co-pilot flies this legthis leg

• M-3 HrsM-3 Hrs: Jump seat and pilot get about 2-3 hours of en-: Jump seat and pilot get about 2-3 hours of en-route nap; co-pilot (pilot flying) gets no sleeproute nap; co-pilot (pilot flying) gets no sleep

• M-40 MinsM-40 Mins: Pilot and jump seat are awoken for the arrival : Pilot and jump seat are awoken for the arrival • Chronic fatigue + sleep inertia?Chronic fatigue + sleep inertia?

• M-20 MinsM-20 Mins: Pilot straps into left seat, descent is already in : Pilot straps into left seat, descent is already in progress; jump seat pilot straps in ~ 10 mins laterprogress; jump seat pilot straps in ~ 10 mins later

Mishap Timeline (cont’d)Mishap Timeline (cont’d)

Sequence of EventsSequence of Events

• First segment of approach 2800 ft high, 35 kts fastFirst segment of approach 2800 ft high, 35 kts fast• Increased tolerance for error and risk?Increased tolerance for error and risk?

• ““Flaps to 40Flaps to 40%” (activated by pilot). “Gear down, %” (activated by pilot). “Gear down, Before Landing Checklist”Before Landing Checklist”• Non-standard procedureNon-standard procedure

• Slat malfunction disables stall warningSlat malfunction disables stall warning• Pilots fixate on slat malfunction, enter slight climbPilots fixate on slat malfunction, enter slight climb

• Task fixation, channelized attention, lack of SATask fixation, channelized attention, lack of SA

• A/C enters IMC. Decel induces pitch-down A/C enters IMC. Decel induces pitch-down sensation: somatogravic illusionsensation: somatogravic illusion• Unrecognized spatial disorientationUnrecognized spatial disorientation

Sequence of Events, contd.Sequence of Events, contd.

• ““Flaps Landing” (100% called for, but not initiated by either Flaps Landing” (100% called for, but not initiated by either pilot). Airspeed appropriate for 100%; 20 kts. too slow for pilot). Airspeed appropriate for 100%; 20 kts. too slow for 40%40%• CRM breakdownCRM breakdown

• Climb continues; pilots interpret 10º pitch up to be Climb continues; pilots interpret 10º pitch up to be combined INS fail.combined INS fail.• Improbable risk assessment; cognitive breakdownImprobable risk assessment; cognitive breakdown

• Stall buffet misinterpreted as turbulence in cloudsStall buffet misinterpreted as turbulence in clouds• Decreased vigilanceDecreased vigilance

• A/C proceeds to >30º AOA, 20º nose up, 55 kts: DepartureA/C proceeds to >30º AOA, 20º nose up, 55 kts: Departure• 60º right bank, 95º left bank, 95º right bank60º right bank, 95º left bank, 95º right bank

• Aero-loading deploys slats, stall warning activates;Aero-loading deploys slats, stall warning activates; pilots begin stall recovery pilots begin stall recovery• 4100 ft altitude loss, level off at 773 ft.4100 ft altitude loss, level off at 773 ft.

Crew learns next day that aircrew error, not windshear,

was the causal factor.

www.flyawake.orgwww.flyawake.org

Take-home Points:Take-home Points:Fatigue / Circadian Rhythm DisruptionFatigue / Circadian Rhythm Disruption

• Fatigue is a natural physiologic stateFatigue is a natural physiologic state

• Normal sleep need: 8 - 8 ¼ hours/dayNormal sleep need: 8 - 8 ¼ hours/day

• High-level problem solving is most High-level problem solving is most susceptiblesusceptible

• Naps help (don’t forget sleep inertia)Naps help (don’t forget sleep inertia)

• Expect circadian rhythm disruptionExpect circadian rhythm disruption

• Fatigue absolutely and significantly Fatigue absolutely and significantly degrades performance!degrades performance!

Questions?

Let’s ask Batman…

Ever in town?Ever in town?

Stop by and Stop by and set a spell!set a spell!

Be Well! Stay Safe! Fly Often!Be Well! Stay Safe! Fly Often!

CDR Walt “Lunar” DalitschCDR Walt “Lunar” Dalitsch Senior Aerospace Medicine Specialist, Branch Clinic, NAS North IslandSenior Aerospace Medicine Specialist, Branch Clinic, NAS North Island

Deputy Specialty Leader, Aerospace MedicineDeputy Specialty Leader, Aerospace Medicine

walter.dalitsch@med.navy.milwalter.dalitsch@med.navy.mil(619) 545-0410(619) 545-0410