Alcohol and drugs14 CFR 91.17 Alcohol or drugs
No person may act or attempt to act as a crewmember of a civil aircraft within 8 hours after drinking any alcoholic beverage, while under the influence of alcohol, while using any drug that affects their faculties in any way contrary to safety, or with an alcohol concentration of 0.04 or greater. Each of these is a separate limit.
By the ATIS Alerts team · Updated October 15, 2026 · Regulation text current as of October 14, 2026. A study aid based on the official regulation text, not legal advice or an FAA interpretation.
At a glance
- No acting as a crewmember within 8 hours after the consumption of any alcoholic beverage (a)(1).
- No acting as a crewmember while under the influence of alcohol (a)(2), or while using any drug that affects your faculties in any way contrary to safety (a)(3).
- No acting as a crewmember with an alcohol concentration of 0.04 or greater in a blood or breath specimen (a)(4).
- Except in an emergency, a pilot may not allow a person who appears to be intoxicated, or who shows signs of being under the influence of drugs, to be carried; a medical patient under proper care is excepted (b).
- Crewmembers must submit to certain law enforcement alcohol tests (c)(1) and furnish certain test results to the FAA on request (c)(2) and (d).
In plain English
Paragraph (a) lists four limits for any person who acts or attempts to act as a crewmember of a civil aircraft: no alcoholic beverage within the previous 8 hours, not under the influence of alcohol, not using any drug that affects the person's faculties in any way contrary to safety, and an alcohol concentration below 0.04. The rule defines alcohol concentration as grams of alcohol per deciliter of blood or grams of alcohol per 210 liters of breath.
Because the four limits are separate, meeting one does not satisfy the others. A person who waited 8 hours but is still under the influence of alcohol, or still has an alcohol concentration of 0.04 or greater, does not meet (a)(2) or (a)(4). The drug limit in (a)(3) is written broadly: it says any drug that affects the person's faculties in any way contrary to safety, and it does not list specific drugs.
Paragraph (b) covers passengers. Except in an emergency, no pilot of a civil aircraft may allow a person who appears to be intoxicated, or who demonstrates by manner or physical indications that the individual is under the influence of drugs, to be carried in that aircraft. A medical patient under proper care is excepted.
Paragraphs (c) through (e) cover testing. A crewmember must submit to a blood or breath alcohol test requested by a law enforcement officer who is authorized under State or local law to conduct it and who is investigating a suspected violation of State or local law governing the same or substantially similar conduct. When the FAA has a reasonable basis to believe a person violated the alcohol or drug limits, that person must, on request, furnish or authorize the release of the results of tests taken within 4 hours after acting or attempting to act as a crewmember. Under (e), that information may be evaluated in determining qualifications for any airman certificate or possible violations, and may be used as evidence in legal proceedings under the Federal Aviation Act of 1958.
Common mistakes
- Treating 8 hours as the whole rule. After 8 hours, the limits in (a)(2) and (a)(4) still apply.
- Thinking the rule covers only the pilot flying. It applies to any person acting or attempting to act as a crewmember (a).
- Assuming the drug limit covers only illegal drugs. Paragraph (a)(3) says any drug that affects the person's faculties in any way contrary to safety.
The official text
14 CFR 91.17 as published on the eCFR, current as of October 14, 2026.
(a) No person may act or attempt to act as a crewmember of a civil aircraft—
(1) Within 8 hours after the consumption of any alcoholic beverage;
(2) While under the influence of alcohol;
(3) While using any drug that affects the person's faculties in any way contrary to safety; or
(4) While having an alcohol concentration of 0.04 or greater in a blood or breath specimen. Alcohol concentration means grams of alcohol per deciliter of blood or grams of alcohol per 210 liters of breath.
(b) Except in an emergency, no pilot of a civil aircraft may allow a person who appears to be intoxicated or who demonstrates by manner or physical indications that the individual is under the influence of drugs (except a medical patient under proper care) to be carried in that aircraft.
(c) A crewmember shall do the following:
(1) On request of a law enforcement officer, submit to a test to indicate the alcohol concentration in the blood or breath, when—
(i) The law enforcement officer is authorized under State or local law to conduct the test or to have the test conducted; and
(ii) The law enforcement officer is requesting submission to the test to investigate a suspected violation of State or local law governing the same or substantially similar conduct prohibited by paragraph (a)(1), (a)(2), or (a)(4) of this section.
(2) Whenever the FAA has a reasonable basis to believe that a person may have violated paragraph (a)(1), (a)(2), or (a)(4) of this section, on request of the FAA, that person must furnish to the FAA the results, or authorize any clinic, hospital, or doctor, or other person to release to the FAA, the results of each test taken within 4 hours after acting or attempting to act as a crewmember that indicates an alcohol concentration in the blood or breath specimen.
(d) Whenever the Administrator has a reasonable basis to believe that a person may have violated paragraph (a)(3) of this section, that person shall, upon request by the Administrator, furnish the Administrator, or authorize any clinic, hospital, doctor, or other person to release to the Administrator, the results of each test taken within 4 hours after acting or attempting to act as a crewmember that indicates the presence of any drugs in the body.
(e) Any test information obtained by the Administrator under paragraph (c) or (d) of this section may be evaluated in determining a person's qualifications for any airman certificate or possible violations of this chapter and may be used as evidence in any legal proceeding under section 602, 609, or 901 of the Federal Aviation Act of 1958.
Test yourself
Practice questions from our free FAA written test prep that cite 14 CFR 91.17.
Recreational Pilot
No person may act as a crewmember of a civil aircraft within how many hours after consuming alcohol?
- A. 8 hours.
- B. 12 hours.
- C. 24 hours.
- D. 4 hours.
Show answer
A. 8 hours. Eight hours from bottle to throttle, and also below 0.04 percent blood alcohol concentration and not under the influence: all three conditions apply. Alcohol's effects on judgment and night vision outlast the legal window.
More Recreational Pilot practice →ATP Multiengine
No person may serve as a required flight crewmember with a blood alcohol concentration of:
- A. 0.04 percent or greater.
- B. 0.08 percent or greater.
- C. 0.10 percent or greater.
- D. any measurable amount.
Show answer
A. 0.04 percent or greater. The limit is 0.04 percent, in addition to the 8-hour bottle-to-throttle rule and the prohibition on being under the influence. Refusing a test, or testing at or above 0.04, is grounds for certificate action.
More ATP Multiengine practice →Basic Ground Instructor
Under 14 CFR 91.17, a person may not act as a crewmember of a civil aircraft:
- A. within 8 hours of consuming alcohol, while under its influence, or with a blood alcohol level of 0.04 percent or greater.
- B. within 12 hours of consuming any alcohol.
- C. within 24 hours of consuming alcohol, in any amount.
- D. with any measurable blood alcohol at all.
Show answer
A. within 8 hours of consuming alcohol, while under its influence, or with a blood alcohol level of 0.04 percent or greater. The regulatory floor is 8 hours bottle-to-throttle, no impairment, and under 0.04 BAC, and all three apply independently, so 9 hours after heavy drinking can still be illegal on the impairment or BAC prongs. Many pilots adopt a more conservative personal standard, but the tested numbers are these.
More Basic Ground Instructor practice →
Questions pilots ask
How long after drinking can a pilot fly?
Not within 8 hours after the consumption of any alcoholic beverage (91.17(a)(1)). The person also may not be under the influence of alcohol (a)(2) or have an alcohol concentration of 0.04 or greater (a)(4), so 8 hours alone may not be enough.
What is the blood alcohol limit for pilots?
No person may act or attempt to act as a crewmember with an alcohol concentration of 0.04 or greater in a blood or breath specimen (91.17(a)(4)).
Can I carry a passenger who is drunk?
Except in an emergency, no pilot of a civil aircraft may allow a person who appears to be intoxicated to be carried (91.17(b)). The same applies to a person who shows by manner or physical indications that they are under the influence of drugs, except a medical patient under proper care.
Does a pilot have to take an alcohol test if a police officer asks?
A crewmember must submit to a blood or breath alcohol test on request of a law enforcement officer who is authorized under State or local law to conduct it and who is investigating a suspected violation of State or local law governing the same or substantially similar conduct prohibited by (a)(1), (a)(2) or (a)(4) (91.17(c)(1)).