Which category describes a passenger who is immobile and unable to sit on an aircraft seat?

The category that accurately describes a passenger who is immobile and unable to sit on an aircraft seat is the one referring to a passenger requiring a stretcher. This designation specifically pertains to individuals who cannot be seated in a traditional aircraft seat due to their medical condition or physical limitations, necessitating transportation on a stretcher for their safety and comfort during the flight.

Passengers requiring a stretcher are typically those with severe medical conditions or injuries that prevent them from sitting upright, making it essential for them to be accommodated in a lying-down position throughout the journey. This is crucial not only for their well-being but also for proper management of their medical needs during transport.

While other categories, such as passengers requiring a wheelchair or extra assistance, address mobility limitations, they imply that the individuals can still occupy a seat with some support, unlike those needing a stretcher who cannot sit at all.