航空救急
Air ambulance services in the United States can be operated by a variety of sources. Some services are hospital-operated, while others may be operated by Federal, State or local government; or through a variety of departments, including local or State police, the United States National Park Service, or fire departments. Such services may be operated directly by any of these EMS systems, or they may be contracted to a third-party provider, such as an aircraft charter company. In addition, it is not uncommon for U.S. military helicopters to be pressed into service providing air ambulance support. The vast distances covered by the U.S. mean that while helicopters may be the preferred form of service delivery for 'on-scene' emergencies, fixed wing aircraft, including small jets, are often used for transfers from rural hospitals to tertiary care sites. These aircraft are typically staffed by a mix of personnel including physicians, nurses, and paramedics, and in some cases, by all three. Publicly operated air ambulance service is supplemented by emergency and non-emergency air transport service, which may be provided by dedicated air ambulance companies, or by aircraft charter companies as a secondary business operation. 3