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