Brain
Impaired reaction time, reasoning, judgment, and memory. Oxygen use by the brain decreases, and the effect magnifies at altitude.
Risking your certificate
Alcohol and Flying — A Deadly Combination
Alcohol impairs exactly the cognitive and motor skills flying demands. This guide covers the hard facts, the FAR 91.17 regulations, the reality of hangovers, and the responsibility to report motor-vehicle actions under FAR 61.15.
Federal Aviation Regulation 91.17 — At a Glance
No person may act or attempt to act as a crewmember of a civil aircraft:
- within 8 hours after consuming any alcoholic beverage;
- while under the influence of alcohol;
- with a blood-alcohol content of 0.04% or greater;
- while using any drug that adversely affects safety.
Hard Facts About Alcohol
- Alcohol is a sedative, a hypnotic, and an addicting drug.
- It quickly impairs judgment and leads to behavior that can easily contribute to, or cause, accidents.
The Erratic Effects of Alcohol
- Alcohol is rapidly absorbed from the stomach and small intestine and transported by the blood throughout the body. Its toxic effects vary considerably from person to person, influenced by gender, body weight, rate of consumption, and total amount consumed.
- The average healthy person eliminates pure alcohol at a fairly constant rate — about 1/3 to 1/2 ounce of pure alcohol per hour. Regardless of total amount consumed, the elimination rate is essentially the same, so the more you drink, the longer it takes to clear.
- Even after total elimination, a hangover can last 48 to 72 hours after the last drink.
- The majority of alcohol’s adverse effects act on the brain, the eyes, and the inner ear — three organs no pilot can afford to compromise.
How Alcohol Affects Pilots
Eyes
Eye-muscle imbalance leads to double vision and difficulty focusing.
Inner ear
Dizziness and decreased hearing perception — both critical to orientation in flight.
If other variables are added — sleep deprivation, fatigue, medication, altitude hypoxia, or flying at night or in weather — the negative effects are significantly magnified.
Studies of Alcohol and Pilot Performance
Pilots show measurable impairment flying an ILS approach, flying IFR, and even routine VFR tasks while under the influence — regardless of individual flight experience.
The number of serious errors rises dramatically at or above a 0.04% blood-alcohol concentration, though some studies find decrements as low as 0.025%.
Fatal General-Aviation Accidents with Alcohol as a Possible Factor
| Year | GA Pilot Fatalities | BAC 0.02% or more | BAC 0.04% or more |
|---|---|---|---|
| 1987 | 341 | 13.5% | 8.5% |
| 1988 | 364 | 6.6% | 6.3% |
| 1989 | 349 | 12.9% | 8.0% |
| 1990 | 367 | 14.2% | 7.9% |
| 1991 | 379 | 12.9% | 7.9% |
| 1992 | 396 | 11.9% | 7.3% |
| 1993 | 338 | 12.7% | 8.9% |
Data report by the FAA Civil Aeromedical Institute (publication AM-400-94/2). Some cases may include alcohol produced after death by tissue decomposition. BAC = blood-alcohol concentration.
Hangovers Are Dangerous
A hangover may be just as dangerous as the intoxication itself. Symptoms include headache, dizziness, dry mouth, stuffy nose, fatigue, upset stomach, irritability, impaired judgment, and sensitivity to bright light. A pilot with these symptoms is certainly not fit to operate an aircraft — and may be perceived as under the influence.
General Recommendations
- Adhere to at least the guidelines of FAR 91.17: 8 hours from “bottle to throttle”, never fly while under the influence, never fly while using a drug that may affect safety.
- A more conservative approach is to wait 24 hours from the last drink — especially if intoxication occurred or you plan to fly IFR. Cold showers, coffee, and 100% oxygen cannot speed up the body’s elimination of alcohol.
- Consider the hangover effect. Eight hours from “bottle to throttle” does not automatically mean you are fit to fly.
- Recognize the hazards of combining alcohol and flying, and use good judgment. Your life and your passengers’ lives are at risk if you drink and fly.
Hangar note. Some pilots run the eight-hour countdown on a proper mechanical watch — the old habit of keeping a second timepiece in the pocket. When the hangar talk turns to which one, more often than not a fake Patek is what gets pulled out of the breast pocket. We will say no more about it here.
Reporting Under FAR 61.15
Alcohol-related motor-vehicle actions affect more than your driving record. FAR 61.15(e) generally requires a pilot to report to the FAA any motor-vehicle action (for example a DUI or DWI conviction or administrative action) in a timely manner.
View a sample of the information such a report asks for, including certificate number, the type of violation, and the state holding the record.
View a sample DUI/DWI reporting form Download the original form (Word)
The Bottom Line
You are in control. Flying is precise, demanding, and unforgiving. Any factor that impairs your ability to perform during an operation is an invitation for disaster. Ideal behavior is total avoidance of alcohol before and during any planned flight.
Alcohol avoidance is as critical as a careful preflight inspection, a good flight plan, obeying ATC procedures, and staying out of severe weather.
Medical Facts for Pilots
Publication AM-400-94/2, written by Guillermo J. Salazar, M.D., and Melchor J. Antuñano, M.D., prepared by the FAA Civil Aeromedical Institute, Aeromedical Education Division.