This article is based on an official press release from the National Transportation Safety Board (NTSB).

NTSB Study Reveals Upward Trend in Drug Presence Among Fatally Injured Pilots

On May 14, 2026, the National Transportation Safety Board (NTSB) released a comprehensive safety research report detailing toxicology results from U.S. civil Incident accidents. The study, titled “2018–2022 Update to Drug Use Trends in Aviation,” analyzed data from 930 pilots who were fatally injured during that five-year period. According to the NTSB press release, the findings highlight a continuing, long-term upward trend in the detection of various medications and substances in aviation accidents.

The most striking statistic from the NTSB’s updated research is that more than half of the fatally injured pilots, 52.8%, tested positive for at least one drug of any type. Furthermore, 27.7% of the pilots tested positive for two or more drugs. While these figures encompass a wide range of substances, including common, non-impairing medications like cholesterol-lowering drugs and cardiovascular prescriptions, the data also points to a rise in the use of potentially impairing substances.

However, the NTSB strongly cautions against jumping to conclusions regarding crash causality. The agency emphasizes that the presence of a drug in post-mortem toxicology testing does not automatically establish that the pilot was impaired while flying, nor does it confirm that the substance contributed to the Accident.

Breaking Down the Toxicology Data

Potentially Impairing and Illicit Substances

While the overall 52.8% figure includes benign medications, the NTSB report isolates data concerning substances that pose a direct risk to aviation safety. According to the study, 28.6% of the fatally injured pilots tested positive for drugs classified as “potentially impairing.” This category encompasses certain prescription medications, controlled substances, illicit drugs, and over-the-counter (OTC) medications.

Notably, the most common potentially impairing substance detected was diphenhydramine. This active ingredient is widely available in over-the-counter allergy and cold medications, such as Benadryl and Unisom. Because it is easily accessible, pilots may underestimate its sedating effects, making it a persistent factor in aviation toxicology reports for over a decade.

In addition to OTC medications, the NTSB noted an increase in the detection of illicit drugs. The study found that 7.4% of the pilots tested positive for illicit substances, a rise driven primarily by the detection of delta-9-THC, the primary psychoactive chemical found in marijuana.

Professionalism and Certification Factors

The General Aviation Divide

The NTSB research highlights a clear demographic and operational divide regarding drug prevalence. The data indicates that drug presence is significantly lower among professional pilots operating under stricter regulatory oversight compared to those in general aviation.

According to the report, pilots conducting Part 135 operations, which include commuter and on-demand flights such as corporate charters and air taxis, exhibited a lower drug presence than pilots operating under Part 91 general aviation rules. Furthermore, pilots holding Airline Transport Pilot (ATP) and Commercial certificates had lower drug detection rates than those holding private, sport, or student certificates, or those flying without any certificate at all.

Medical certification also played a crucial role. The NTSB found that pilots holding an active Federal Aviation Administration (FAA) medical certificate had a lower rate of drug presence than those flying without one, underscoring the effectiveness of routine medical evaluations in the professional aviation sector.

Understanding the Findings: Presence vs. Impairment

AirPro News analysis

When analyzing the NTSB’s findings, we must draw a distinct line between “drug presence” and “active impairment.” Toxicology tests, particularly post-mortem examinations, detect inactive metabolites that can remain in blood or tissue long after a drug’s psychoactive or impairing effects have dissipated. This is especially true for substances like THC and certain long-lasting prescription medications.

The NTSB’s stated purpose for this study is to document trends and provide context for factors that may affect aviation Safety, rather than to assign direct causality to these drugs in specific crashes. However, the persistent presence of diphenhydramine highlights a critical gap in pilot education regarding self-medication.

The FAA maintains strict guidelines regarding over-the-counter medications. Because diphenhydramine has a long half-life and known sedating properties, the FAA advises that pilots must wait at least 60 hours, calculated as five times the drug’s half-life, after their last dose before resuming flying duties. The fact that this specific antihistamine remains the most detected potentially impairing drug suggests that many general aviation pilots are either unaware of the 60-hour rule or are failing to adhere to it.

Historically, the trend is moving in a concerning direction. The NTSB’s previous study covering 1990 to 2012 noted that the proportion of pilots testing positive for at least one drug increased from 10% in 1990 to 40% in 2012. The current leap to 52.8% for the 2018–2022 period indicates that the aviation Manufacturers, particularly the general aviation sector, requires renewed educational campaigns focused on the hidden dangers of common medications.

Frequently Asked Questions (FAQ)

Does a positive drug test mean the pilot caused the crash?

No. The NTSB explicitly states that a positive toxicology result indicates the presence of a drug or its metabolites in the pilot’s system, but it does not necessarily mean the pilot was impaired at the time of the crash or that the drug contributed to the accident.

What was the most common impairing drug found?

According to the NTSB study, the most common potentially impairing drug detected was diphenhydramine, an over-the-counter antihistamine commonly found in allergy and cold medications like Benadryl.

Are airline pilots testing positive at the same rate as private pilots?

No. The study found that professional pilots (those with ATP or Commercial certificates, and those flying Part 135 operations) had significantly lower rates of drug detection compared to general aviation pilots with lower-level certifications.

Sources:
National Transportation Safety Board (NTSB) Press Release: “NTSB Releases Study on Drug Presence Trends Among Fatally Injured Pilots”