Fatigue in Aviation Mads Klokker

Fatigue in Aviation
Mads Klokker
IAAMS, AsMA
Rigshospitalet
2015
Charles Lindbergh
about his 1927 transatlantic flight:
Fatigue Fatalities
Explosion of the Shuttle Challenger
NASA launches shuttle despite conference with specialists — In
addition decision makers had been working long hours under
tremendous pressure. Shuttle destroyed, crew lost, NASA suffers
huge PR fallout.
Exxon Valdez
Crash of American Airlines Flight 1420
Third mate misses light and buoy marking
shore and crashes into reef after hours of
duty without sleep. 11 million barrels of oil
spilled.
Experienced pilot lands in severe weather (75 mph gusts) after 13 hours
on duty. Eleven killed.
Single Vehicle Car Crashes
”My mind clicks on and off.
I try letting one eyelid close at a time.....
but the effect is too much, the sleep is winning...
nothing life can attain is so desirable as sleep.
My mind is losing resolution and control.”
Driver fell asleep going home from work. In Denmark it is assumed that in ¼ of
all fatalities sleepiness is a significant factor.
NB: Obstructive Sleep Apnea Syndrome is reported in 1 – 4% of adult Danes!
Types of Fatigue
✈ Definition: A state of diminished physical and/or
mental efficiency.
✈ Types of Fatigue
–
–
–
–
•
Flight Fatigue
Definition:
A physiological state of reduced mental or
physical performance capability resulting
from sleep loss or extended wakefulness,
circadian phase, or workload that can impair
a crew member’s alertness and ability to
safely operate an aircraft or perform safety
related duties.
IATA, ICAO, IFALPA, July 2011.
Acute - Work induced
Chronic - Repeated sleep loss
Subjective - Stress-induced fatigue
Circadian rhythm - shift work & jet lag
Micro-sleeps!
Official Fatigue Statistics are only the
Top of the Iceberg!
Aviation, Space, & Environmental Medicine Sept. 1998:
Gander et al. (NASA):
Crew Factors in Flight Operations:
The Initial NASA-Ames Field Studies on Fatigue
FLIGHT CREW FATIGUE:
I: Objectives and Methods
II: Short-Haul Fixed-Wing Air Transport Operations
III: North Sea Helicopter Air Transport Operations
IV: Overnight Cargo Operations
V: Long-Haul Air Transport Operations
VI: A Synthesis -
Aviation, Space, & Environmental Medicine Sept. 1998:
Gander et al. (NASA): Flight Crew Fatigue II:
Short-Haul Fixed –Wing Air Transport Operations
Aviation, Space, & Environmental Medicine Sept. 1998:
Gander et al. (NASA): Flight Crew Fatigue II:
Short-Haul Fixed –Wing Air Transport Operations
Slept less (accumulation)
Awoke earlier
Difficulty to fall asleep
Lighter, less restful sleep
Poorer overall sleep quality
More snacks than regular meals
More caffeine
More alcohol
(”night cap” as relaxing means)
Aviation, Space, & Environmental Medicine Sept. 1998:
Gander et al. (NASA): Flight Crew Fatigue II:
Short-Haul Fixed –Wing Air Transport Operations
Aviation, Space, & Environmental Medicine Sept. 1998:
Gander et al. (NASA): Flight Crew Fatigue II:
Short-Haul Fixed –Wing Air Transport Operations
Subjective symptoms reported:
Recommendations:
Headache
Congested nose
Back pains
Sleep loss should be reduced by including the duration of the
duty day as a factor of the subsequent rest period
Successive duty days should begin at the same time
Better life style
Factors Affecting Sleepiness
Circadian Rhythm - Efficiency
✈Prior sleep/wakefulness
✈Age
✈Medical conditions
✈Medications
✈Alcohol
✈Environmental/work conditions
✈Circadian phase
Sleep Cycle
Fatigue and flying
Awake
✈Accept lower standards
✈Lack of patience
✈More forgetful
✈Instrument cross check breaks down
✈Reduced Situational Awareness
✈Slows reaction time
✈Reduced G tolerance
✈Micro-sleep
Drowsy
state
REM
Stage 1
Stage 2
Stage 3
Stage 4
1
2
3
4
5
HOURS
6
7
8
Alertness Management Strategies
✈Preventive strategies
–
Used before duty and on layovers to reduce the
adverse effects of fatigue, sleep loss, and
circadian rhythm disruption
✈Operational strategies
–
Preventive Strategies
Sleep Scheduling and Quantity
Symptoms of Jet Lag
✈ Disturbed sleep
➢ inability to fall asleep or stay asleep
✈ Increased drowsiness
✈ Exhaustion
✈ Decreased physical or mental performance
✈ Headache
✈ More negative moods
✈ Loss of appetite
✈ Gastrointestinal problems
✈ Limited peripheral vision
✈ Impaired night vision
Used in flight to maintain alertness and
performance
✈At home
–
Sleep debt tends to increase while traveling
✈At stopover
–
Try to get the same amount of sleep in a 24 hour
period as you normally get at home
✈Trust your own physiology
–
–
If you wake up spontaneously and can’t get back to
sleep in 15-30 minutes, get up
If you’re sleepy and circumstances permit, sleep
Preventive Strategies
Good Sleep Habits
✈Sleep Environment
–
–
–
–
Dark room
Quiet room
Comfortable temperature
Comfortable sleep surface
✈Lifestyle
–
–
–
Operational Strategies
✈During flight operations
–
–
Engage in conversation with others
Do something that involves physical action
•
–
Strategic caffeine consumption (if available)
Exercise regularly
Avoid alcohol and caffeine
Eat a balanced diet
Preventive Strategies
Strategic Napping
✈Before duty
–
–
–
–
–
Writing, stretching, isometric muscle contraction
A nap can improve alertness
If immediately before a duty period, limit nap to
45 minutes or less
Avoid sleep inertia
Naps can last up to 2 hours
Some sleep is better than none
Operational Strategies
✈During flight operations
–
–
Engage in conversation with others
Do something that involves physical action
•
–
Writing, stretching, isometric muscle contraction
Strategic caffeine consumption (if available)
East to West Travel
or
Early to Late Shift
Further Considerations
✈Bright light
6
Hours Out of Phase
5
OUTDOOR
4
✈Pharmacological agents
✈Exercise
3
INDOOR
2
✈Diet
✈“Anchor sleep”
1
0
0
2
4
6
8
Days of Recovery
West to East Travel
or
Late to Early Shift
Sleep Apnoea Syndrome
6
Hours Out of Phase
5
OUTDOOR
4
3
INDOOR
2
1
0
0
2
4
Days of Recovery
6
8
EASA:
(5) sleep apnoea syndrome Class 1&2
(h) Sleep apnoea syndrome
Applicants with unsatisfactorily treated sleep
apnoea syndrome should be assessed as unfit.
Risk Assessment in Aviation
(commercial pilot)
1%
Shift Working
✈Working Schedule:
Avoid: Late to early shift
Prefer: Early to late shift
Advancing 2-2-1
rotation (FAA)
0
Delaying 2-2-2
rotation (USAF)
14
10
24
16
Duty
14
10
48
72
24
16
Off-Duty
80
96
24
120
16
144
168
48
192
Time of day
Moebus...
• a large number of duty hours in a short time;
• long duty hours (which are not only directly fatigue inducing but which also
may interfere with rest periods);
• split duty (which creates similar problems to those of long duty periods);
• night duty (which combines duty at circadian low with extended waking and
18 h awake ~ 0.05 %
alcohol
suboptimal temporal position of rest periods);
• early start of duty (which negates the value of the prior rest period);
• rest periods given outside the window of circadian low (which reduces the
recuperative value);
• recovery time after time zone flights (that have induced shifts in the
circadian
system);
• standby duty (which often is as fatigue inducing as actual duty);
• the recuperative value of rest facilities (bunk-seat-environment-standby).
Moebus - recommendations
Moebus
• The permissible maximum of 180 duty hours in 3 consecutive weeks allows for a
high density of work hours in a short period of time and should be limited through an
additional provision for a maximum of 100 duty hours in 14 consecutive days (Q1);
• The maximum daily flight duty period (13/14 hours) exceeds reasonable limits
especially under exacerbating circumstances (e.g. high workload, night flying,
acclimatization) and should be reduced. Also, extensions to the maximum
FDP should not be permitted (Q2 & 3). Night duties need special provisions and must
not be combined with other sources of fatigue (Q4);
• In general, the same duty/rest rules should apply to cabin crew as to cockpit crew –
the fatigue of the former is often very high (Q5 & 13);
• Split duty often combines several sources of fatigue (early starts, long periods
of wakefulness, late bedtimes) and should be used only outside the WOCL and for a
maximum of 14 hours (start of first sub-duty to end of last sub-duty) (Q6);
• Home base recovery days after time zone crossings should be provided according to
the number of time zones crossed and the duration of the layover (see Table 1) (Q7);
• Reduced rest periods (<12 hours) should be avoided and, if used, be applied within a
FRMS, and then only if the entire WOCL is included in the rest period (Q8);
Moebus - recommendations...
• Permitting (as an exception) a FDP to start at 04:00h after a rest period would
negate the effect of the rest period and should be omitted from EU OPS (Q9);
• The format of rest periods should include a provision for “local night”, defined as 10 hours between
22:00h and 10:00h to ensure proper rest. The length of
the rest period needed after a number of consecutive days on duty is not possible to answer in a
detailed way because of a lack of scientific data, but the present provision of a weekly rest period after
168 hours of duty falls short of reasonable requirements (Q10);
• To maintain alertness during extended FDP operations, augmented crews should be allowed to take
in-flight rest. The quality of on-board rest conditions (e.g. bunk-economy seat) will determine the
recuperative value of the rest period and will be modified by acclimatization level (Table 2) (Q11 &
12);
• Airport standby time carries approximately the same fatigue load as work and should count as FDP
unless a FRMS is applied with proper rest facilities (14). Standby time with proper rest facilities is still
likely to involve reduced recuperative value because of anticipatory stress influences (of imminent
duty), but the quantitative effects cannot be determined because of a lack of scientific data (Q15 & 16);
• With respect to breaks there is a large body of research and regulation – a 20 minute meal break for
each 6 hours of work may be a lower limit but for cabin crew the physical load should raise this to 30
minutes for every 6 hours of duty. To avoid dehydration problems, an additional 10 minute break
should be provided in each 3 hour period that does not contain a meal break (Q17);
• Permanent or a large number of successive night duties should not be exempt from the present rules,
since adaptation to night work probably does not occur. However, data relating to aircrew are limited
(Q18).
Man fulgte ikke anbefalingerne fra det EUnedsatte ekspertudvalg....
2015
Stress Factors
Lavprisselskaber:
Arbejdsmæssige rettigheder
Uniform
Sygepenge
Pension mv.
Stress Factors
END!
Link:
http://www.aeromedicalguidelines.com