[Skip to Content]
[Skip to Content Landing]
December 2, 1974

Effects of Marihuana on Flying Ability

Author Affiliations

University of California School of Medicine San Diego

JAMA. 1974;230(9):1258. doi:10.1001/jama.1974.03240090018013

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.


To the Editor.—  Since being informed of a number of instances in which pilots have flown aircraft while "high" on marihuana, we have studied the effects of marihuana intoxication on the ability of certified pilots to operate a general aviation model ATC-510 instrument flight simulator.Three professional and three private pilots were recruited. All had a history of smoking marihuana for several years and could currently be described as infrequent marihuana users. The pilots were familiarized with a specific flight sequence that included maneuvers typically encountered in instrument flight (straight and level flight, turns, three-dimensional maneuvering, radio navigation). After the pilots attained proficiency in "flying" the simulator and in the specific flight sequence, standardized marihuana (6.3 mg of Δ9 tetrahydrocannabinol) or a matched marihuana placebo (0.2 mg of Δ9 tetrahydrocannabinol), supplied by the National Institute of Drug Abuse, was smoked over a 10-minute period in a pipe, utilizing