A new report by the United States National Transportation Safety Board (NTSB) has found that more than half of pilots who died in aviation accidents had at least one drug in their system. Released on 14 May 2026, the study examined toxicology results from 930 fatal accidents involving pilots in US civil aviation between 2018 and 2022. The findings have prompted safety experts to call for stronger drug monitoring for private pilots across the country.
One result stands out: 52.8% of the 930 fatally injured pilots tested positive for at least one drug. The list included common prescription medicines, such as drugs for heart conditions or high cholesterol, as well as over-the-counter medications that can be bought without a doctor’s prescription. A positive toxicology result does not automatically prove that a drug caused a crash — a substance can be present in the body without affecting how a pilot performs. Even so, the NTSB considers the pattern alarming.
The agency is more worried about a group of substances it calls “potentially impairing” drugs — medicines that can reduce a person’s ability to concentrate, react quickly, or make sound decisions. These were detected in 28.6% of the pilots tested. The most common was diphenhydramine, a sedating antihistamine found in many allergy tablets and night-time cold and flu medicines. Many people take it without realising it can cause drowsiness and slow reaction times for hours afterwards.
The study also recorded a rise in illicit drug use. Detection of illicit drugs climbed to 7.4%, driven mainly by delta-9-THC, the main psychoactive chemical in cannabis. The NTSB noted that the trend has coincided with the legalisation of marijuana in a growing number of US states. Safety advocates are now urging clearer guidance on cannabis and aviation as more states continue to decriminalise or legalise its use.
One detail helps explain why the numbers may be so high. Almost all the accidents in the study involved small general aviation aircraft — private planes and light training aircraft — rather than large commercial airliners. Commercial airline pilots face strict medical testing and regular drug screening. Private pilots are subject to far less oversight, which means drug use can easily go undetected until something goes wrong.
The NTSB does not have the authority to create new laws, but its safety recommendations carry significant weight with regulators. The board is expected to call on the Federal Aviation Administration (FAA) to strengthen drug education programmes for general aviation pilots and improve awareness of how everyday medicines can affect flying performance. The NTSB has also said it will continue to monitor trends in pilot drug detection in future studies.
Key vocabulary:
- toxicology – the science of detecting drugs, alcohol, or poisons in the body, often used in accident investigations to check if substances were present
- potentially impairing – a classification used by the NTSB for drugs that may reduce a person’s ability to concentrate, react, or make decisions safely
- diphenhydramine – a sedating antihistamine found in many common allergy and cold medicines; it can cause drowsiness and slow reaction times
- delta-9-THC – the main psychoactive (mind-altering) chemical found in cannabis (marijuana)
CEFR Level B1-B2 / ICAO Level 4-5