What term is used for a passenger who cannot travel in a regular seat and must be accommodated horizontally?

The term for a passenger who cannot travel in a regular seat and must be accommodated horizontally is "Stretcher Passenger." This designation is used specifically in aviation to refer to individuals who, due to medical conditions, injuries, or specific health requirements, need to lie flat during their flight. Such passengers typically require specialized medical support and equipment, including a stretcher, to ensure their safety and comfort while traveling. Airlines must make special arrangements to transport these passengers, often involving additional personnel or equipment during boarding and disembarking.

Other terms like assisted traveler, medical passenger, or special needs passenger do exist within the context of travel assistance but do not specifically refer to the requirement to be accommodated in a horizontal position, which is unique to stretcher passengers.