Aeromedical Factors

To prevent these symptoms, it is recommended that an the appropriate actions during routine occurrences, as well ample supply of water be carried and used at frequent as abnormal situations. The influence of alcohol drastically intervals on any long flight, whether thirsty or not. The body reduces the chances of completing a flight without incident. normally absorbs water at a rate of 1.2 to 1.5 quarts per hour. Even in small amounts, alcohol can impair judgment, Individuals should drink one quart per hour for severe heat decrease sense of responsibility, affect coordination, constrict stress conditions or one pint per hour for moderate stress visual field, diminish memory, reduce reasoning ability, and conditions. If the aircraft has a canopy or roof window, lower attention span. As little as one ounce of alcohol can wearing light-colored, porous clothing and a hat will help decrease the speed and strength of muscular reflexes, lessen provide protection from the sun. Keeping the flight deck well the efficiency of eye movements while reading, and increase ventilated aids in dissipating excess heat. the frequency at which errors are committed. Impairments in vision and hearing can occur from consuming as little as Alcohol one drink. Alcohol impairs the efficiency of the human body. [Figure 17-8] Studies have shown that consuming alcohol The alcohol consumed in beer and mixed drinks is ethyl is closely linked to performance deterioration. Pilots must alcohol, a central nervous system depressant. From a medical make hundreds of decisions, some of them time-critical, point of view, it acts on the body much like a general during the course of a flight. The safe outcome of any flight anesthetic. The “dose” is generally much lower and more depends on the ability to make the correct decisions and take slowly consumed in the case of alcohol, but the basic effects on the human body are similar. Alcohol is easily and quickly absorbed by the digestive tract. The bloodstream absorbs Type Beverage Typical Serving Pure Alcohol about 80 to 90 percent of the alcohol in a drink within 30 (oz) Content (oz) minutes when ingested on an empty stomach. The body Table wine 4.0 .48 requires about 3 hours to rid itself of all the alcohol contained Light beer 12.0 .48 Aperitif liquor 1.5 .38 in one mixed drink or one beer. Champagne 4.0 .48 Vodka 1.0 .50 While experiencing a hangover, a pilot is still under the Whiskey 1.25 .50 influence of alcohol. Although a pilot may think he or she is 0.01–0.05% average individual appears normal functioning normally, motor and mental response impairment (10–50 mg) is still present. Considerable amounts of alcohol can remain 0.03–0.12%* mild euphoria, talkativeness, decreased in the body for over 16 hours, so pilots should be cautious (30–120 mg) inhibitions, decreased attention, impaired about flying too soon after drinking. judgment, increased reaction time 0.09–0.25% emotional instability, loss of critical Altitude multiplies the effects of alcohol on the brain. When (90–250 mg) judgment, impairment of memory and combined with altitude, the alcohol from two drinks may have comprehension, decreased sensory response, mild muscular incoordination the same effect as three or four drinks. Alcohol interferes with the brain’s ability to utilize oxygen, producing a form 0.18–0.30% confusion, dizziness, exaggerated of histotoxic hypoxia. The effects are rapid because alcohol (180–300 mg) emotions (anger, fear, grief), impaired passes quickly into the bloodstream. In addition, the brain visual perception, decreased pain sensation, impaired balance, staggering is a highly vascular organ that is immediately sensitive to gait, slurred speech, moderate muscular changes in the blood’s composition. For a pilot, the lower incoordination oxygen availability at altitude and the lower capability of 0.27–0.40% apathy, impaired consciousness, stupor, the brain to use the oxygen that is available can add up to a (270–400 mg) significantly decreased response to deadly combination. stimulation, severe muscular incoordination, inability to stand or walk, vomiting, incontinence of urine and feces Intoxication is determined by the amount of alcohol in the bloodstream. This is usually measured as a percentage by 0.35–0.50% unconsciousness, depressed or weight in the blood. 14 CFR part 91 requires that blood (350–500 mg) abolished reflexes, abnormal body alcohol level be less than .04 percent and that 8 hours pass temperature, coma, possible death from respiratory paralysis (450 mg or above) between drinking alcohol and piloting an aircraft. A pilot with a blood alcohol level of .04 percent or greater after 8 hours * Legal limit for motor vehicle operation in most states is 0.08 cannot fly until the blood alcohol falls below that amount. or 0.10% (80–100 mg of alcohol per dL of blood). Even though blood alcohol may be well below .04 percent, a pilot cannot fly sooner than 8 hours after drinking alcohol. Figure 17-8. Impairment scale with alcohol use. 17-15