Simulated flying performance after marihuana intoxication.

Abstract

Ten pilots smoked, in counterbalanced order on a double blind basis, a social dose of marihuana (.09 mg/kg delta-9-tetrahydrocannabinol) and a matched placebo after being trained to fly a specific flight sequence on an ATC-510 flight simulator. In contrast to placebo, marihuana caused a gross decrement in flying performance, with increased prevalence of major errors, minor errors, altitude deviations, heading deviations, and radio navigation errors. These effects of active marihuana persisted for at least 2 hr and generally had disappeared by 4 to 6 hr after marihuana administration.