14 CFR Part 91 · Subpart A · General
14 CFR 91.17: Alcohol and drugs: the eight-hour rule
No one may act as a crewmember within 8 hours of drinking alcohol, while under its influence, with an alcohol concentration of 0.04 or more, or while using any drug that impairs them. Pilots also may not carry an intoxicated passenger, except in an emergency or a medical patient under care.
Section last amended December 30, 2016 · Text current as of October 15, 2026 · Also cited as FAR 91.17 · Read it on eCFR
14 CFR 91.17 in plain English
- Eight hours from the last drink to acting as a crewmember. (a)(1)
- Never while under the influence, whatever the time since the last drink. (a)(2)
- No drug that affects your faculties contrary to safety, prescription or not. (a)(3)
- Alcohol concentration must be below 0.04 grams per deciliter of blood or per 210 liters of breath. (a)(4)
- Do not carry a passenger who appears intoxicated or under the influence of drugs, except in an emergency or a medical patient under proper care. (b)
- Submit to a test when a law enforcement officer asks under state law, and give the FAA results of tests taken within 4 hours of flying when it has reason to ask. (c)
Common questions
- Is eight hours enough?
- Only if you are also no longer under the influence and below 0.04. All three limits in paragraph (a) apply, so eight hours is the minimum, not a guarantee.
- Does it cover cannabis that is legal in my state?
- Paragraph (a)(3) prohibits any drug that affects your faculties contrary to safety, and FAA medical standards treat marijuana as disqualifying regardless of state law.
Official text of 14 CFR 91.17
§ 91.17 Alcohol or drugs. Verbatim from the eCFR, current as of October 15, 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.