The most famous recent instance of an emergency landing due to a "biohazard" medical issue occurred on Delta Air Lines Flight 194 on September 1, 2023. The Airbus A350 was en route from Atlanta to Barcelona when it was forced to make a U-turn over central Virginia. The pilot reported to air traffic control that a passenger had suffered severe diarrhea "all the way through the airplane," creating a significant health and safety concern for those on board. The aircraft returned to Hartsfield-Jackson Atlanta International Airport, where it underwent a deep cleaning and disinfection process that lasted several hours. Passengers were eventually transferred to another aircraft and arrived in Spain with a delay of more than eight hours. This event remains a primary case study in 2026 for airline biohazard protocols and the logistical challenges of managing mid-flight medical emergencies.