Off-duty pilot pleads guilty after attempting to disable engines on flight while using psychedelic mushrooms

A former Alaska Airlines pilot pleaded guilty or no contest Friday to charges tied to an October 2023 incident in which he attempted to disable the engines of a Horizon Air passenger jet while off duty and after taking psychedelic mushrooms, court filings and statements show.

Joseph Emerson reached plea agreements with state and federal prosecutors, his attorney, Noah Horst, told the Associated Press. Horst said the deals were intended to allow Emerson to take accountability without serving additional jail time. Emerson also expressed regret for endangering passengers and harming the reputation of his profession, according to the attorney.

The incident occurred on an October flight that departed from Everett, Washington, bound for San Francisco. Investigators say Emerson, who was off duty but aboard the plane and in the cockpit, pulled handles that could have cut fuel to the engines. Flight crew members restrained him and the aircraft, carrying more than 80 people, diverted to Portland where it landed safely.

Multnomah County Deputy District Attorney Eric Pickard called Emerson's actions "reckless, selfish, and criminal" in a Friday statement. Federal and state authorities jointly handled the investigation, and the plea agreements resolve charges filed in both jurisdictions, the attorney for Emerson said.

Court records and prosecutors' statements said Emerson had taken psychedelic mushrooms before boarding. Psilocybin, the active compound in such mushrooms, is a hallucinogen that can cause altered perception, disorientation and impaired judgment. While it has been the subject of recent clinical research for certain psychiatric conditions, health experts caution that recreational use can produce unpredictable effects and impair decision-making.

The flight crew's response and the aircraft's diversion prevented injuries or damage to the airplane, officials said. Emergency procedures were followed after crew members identified and restrained the interfering individual, and local authorities took him into custody upon landing.

Emerson's plea resolves the criminal proceedings against him, but the agreements and filings did not specify further disciplinary actions that could be taken by his former employer or federal aviation regulators. Aviation authorities typically review incidents involving cockpit access and crew conduct, and separate administrative processes can include revocation or suspension of pilot certifications.

The episode drew attention to safety protocols around cockpit access and to the potential consequences of substance impairment in aviation settings. Federal and airline rules generally prohibit cockpit access by nonassigned crew during flight and bar crew members from reporting for duty while impaired by intoxicants.

Prosecutors said the plea would hold Emerson accountable for his actions without subjecting him to additional prison time. Defense counsel characterized the agreements as a way for Emerson to accept responsibility and move forward. Further court proceedings will determine any legal penalties spelled out in the plea deals and whether additional civil or administrative reviews will follow.

The case adds to broader public discussion about substance use, mental health and safety in high-responsibility professions, as researchers and regulators continue to assess the risks and potential therapeutic roles of substances such as psilocybin. Officials involved in the prosecution emphasized the seriousness of interfering with aircraft operations and urged that the incident be remembered for how narrowly it missed causing greater harm.