Alcohol in AviationAlcohol in Aviation
by
Dr. Thomas Trozzi
FAR 91.17FAR 91.17
A) Within 8 hours after consumption
alcohol
B) While under the influence of alcohol
C) While having .04 percent by weight or more alcohol in the blood.
Important FactsImportant Facts
1) Two out of three adults in the United States drink alcohol
2) Alcohol is involved in 30% of all drowning and 60% of boat fatalities
3) 40% of all traffic fatalities involve the use of alcohol
Important Facts ContinuedImportant Facts Continued
4) During the 1960’s, 43% of all general aviation fatalities involved alcohol use
5) Present day statistics indicate 30% of GA fatalities involve alcohol
Genetics of AlcoholGenetics of Alcohol
A) Genetic predisposition toward alcohol abuse
B) Research indicates a mutation of the molecular structures of enzymes
C) Heredity also affects alcohol use
Alcohol At Work In The BodyAlcohol At Work In The Body
1) Alcohol is classified as a sedative, tranquilizer, hypnotic and addicting drug
2) In moderate amounts, alcohol causes:
relaxation, stimulation of the appetite and creates a state of euphoria
3) In large amounts, alcohol is toxic
Alcohol AbsorptionAlcohol Absorption
o Watery drinkso Fatty foodso Carbonated
beverages
o Physical, mental and emotional state
o Body chemistryo Gender
differences
Alcohol In The Brain (Behavior)Alcohol In The Brain (Behavior)
A. Friendlier
B. Gregarious
C. Release of sexual inhibitions
D. Jeckyll and Hyde personality changes
Alcohol In The LiverAlcohol In The Liver Alcohol is broken down in steps by
enzymes Only 5% of alcohol is eliminated from
breath, urine, sweat. The rest from the liver
Alcohol is processed by the liver at the rate of 0.3 oz. pure ethanol per hour (less than 1oz. of whiskey)
In large amounts, alcohol can damage the liver resulting in liver disease
Liver DiseaseLiver Disease
Decreased gluconeogensis resulting in hypoglycemia
Impaired blood detoxification
Loss of bile, prothrobin and albumin production
Alcohol In The BrainAlcohol In The Brain
1) Stimulation and agitation
2) Euphoria (false sense of well being)
3) Depresses and sedates
4) Anesthetizes
5) Hypnotic state and sleep
6) Impairs the ability of the brain to use oxygen
Alcohol And Motor AbilityAlcohol And Motor Ability Muscle function Reaction time Eyesight:
1. Depth perception
2. Night vision
3. Eye muscle imbalance Vestibular apparatus
Brain And CNS InvolvementBrain And CNS Involvement
o Lost ability to retrieve and consolidate information
o Cognitive ability impairment
o Altered production of brain RNA
o Altered brain chemistry
BAC% And Associated SymptomsBAC% And Associated Symptoms
0.01-0.05%
Appears normal
0.03-0.12%
Mild euphoria, talkativeness, decreased inhibitions, attention, impaired judgment, reaction time
0.09-0.25%
Emotional instability, loss of critical judgment, memory, comprehension, muscle in-
coordination
BAC% And Associated SymptomsBAC% And Associated Symptoms
0.18-0.30%
Confusion, dizziness, emotional instability, impaired visual, balance, slurred speech
0.27-0.40%
Apathy, impaired consciousness, stupor, severe muscle in-
coordination
0.35-0.50%
Unconsciousness, possible death (respiratory failure)
Alcohol’s Effect In The CockpitAlcohol’s Effect In The Cockpit
Sensory Gathering:o 70% of spatial orientation cues come
from vision for both VFR and IFRo Nystagmus(rapid oscillatory eye
movement)o Positional Alcohol Nystagmus(PAN)o Vestibular apparatus involvement
Cognitive Interpretation:Cognitive Interpretation:
Planning Sequencing
Judgment Perception
Cognition Discrimination
Calculation Association
Attention Voluntary Response
VigilanceInformation Processing
Cognitive Interpretation:Cognitive Interpretation:
1. Alcohol impairs nearly every aspect of information gathering by the brain.
2. Information gathering narrows at 0.04% BAC
Cognitive Interpretation Cognitive Interpretation ContinuedContinued::
3.Decision making and reaction time are impaired at 0.09% BAC
4. Attention deficits occur as low as 0.02% BAC
Boeing 727-232 Simulator TestsBoeing 727-232 Simulator Tests
• Highly trained experienced pilots flew for 8 sessions over the same course.
• Planning, performance and procedural errors were noted along with failures of vigilance beginning at the lowest BAC of 0.025% as compared with 0% BAC.
• Post alcohol impairment was observed for 14 hours after alcohol intake
Degrees of ImpairmentDegrees of Impairment
Degree of impairment associated with a given BAC, is not constant and may vary among individuals. This may be attributed to tolerance. Tolerance is a decrease in magnitude of an effect after repeated exposure to alcohol. More experience drinkers show less impairment than less experienced drinkers.
Other Factors Influencing Other Factors Influencing The Effects Of BACThe Effects Of BAC
Sleep Deprivation
Altitude Hypoxia
Fatigue Night Flying
Medication UseBad Weather
Flying
Psychomotor ResponsePsychomotor Response
Impairment in control manipulation begins as low as 0.035% and rises as BAC increases
Reaction time tasks are impaired by BAC levels of 0.09 %
Psychomotor and spatial orientation capabilities are impaired at 0.1%
Complex task performance and reaction time is impaired at BAC of 0.04 %
Psychological Aspects Of AlcoholPsychological Aspects Of Alcohol
The euphoria induced by alcohol as well as the impairment of judgment, may cause a pilot to undertake maneuvers that he would not under take while sober. This leads to risk taking on the part of the pilot while he is already performance challenged.
Physical Aspects Of Alcohol:Physical Aspects Of Alcohol:
Slows heart rate as well as breathing mechanism.
Prevents proper cellular oxygenation resulting in hystoxic hypoxia
At altitude the effects of alcohol are additive and not synergistic in producing hypoxia
Alcohol produces induced hypoglycemia which lowers blood sugar and affects pilot performance
Hangover Effect:Hangover Effect:
Post alcohol impairment(PAI) has been defined, as performance impairment after alcohol is no longer detectable.
PAI has been observed 14 hours after alcohol ingestion (0.08 to 0.01% BAC) in simulated flight tests.
Symptoms Associated With PAISymptoms Associated With PAI
Headache Stomach Upset
Dizziness Irritability
Dry MouthImpaired
Judgment
Stuffy NoseIncreased
Sensitivity To Light
Fatigue
Conclusion:Conclusion:
FAR 91. 17
No person may operate or attempt to operate an aircraft:
1. Within 8 hours of having consumed alcohol
2. While under influence of alcohol
3. With a BAC of 0.04% or greater
Conclusion Continued:Conclusion Continued:
Flying is a complex task involving, sensory, cognitive and psychomotor operations. Alcohol impairs all flying skills at all levels.
Any concentration of alcohol in a pilot is unacceptable and constitutes a serious hazard.
Recommendation: 24 hours bottle to throttle
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