In Plain English
FAR 91.17 sets the rules for alcohol and drug use by crewmembers of civil aircraft. You may not act — or attempt to act — as a crewmember:
- Within 8 hours after drinking any alcoholic beverage (the "8 hours bottle-to-throttle" rule)
- While under the influence of alcohol
- While using any drug that affects your faculties contrary to safety
- With a blood alcohol concentration (BAC) of 0.04 or greater
Note that the 8-hour rule is a minimum — you can still be in violation if you're impaired or over 0.04 BAC even after 8 hours.
Except in an emergency, you also can't carry passengers who appear intoxicated or under the influence of drugs (medical patients under proper care are excepted).
If a law enforcement officer authorized under state or local law requests an alcohol test, you must submit. The FAA can also request your test results within 4 hours of acting as a crewmember if it suspects a violation. This information can be used to evaluate your airman certificate qualifications and as evidence in legal proceedings.
Why it matters: alcohol and drug impairment dramatically degrade judgment, reaction time, and coordination — and the FAA treats violations of 91.17 as among the most serious certificate actions.
Regulation Text
14 CFR § 91.17§ 91.17 Alcohol or drugs.
(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.
[Docket 18334, 54 FR 34292, Aug. 18, 1989, as amended by Amdt. 91-291, June 21, 2006]