Aviation medicine is essentially a form of occupational medicine and flight surgeons are tasked with the responsibility of maintaining the military's strict medical standards, especially the even stricter standards that apply to those on flying, controlling or jump (airborne) status. In the U.S military, flight surgeons are trained to fill general public health and occupational and preventive medicine roles, and are only infrequently "surgeons" in an operating theater sense. Flight surgeons are typically rated aviators on flight status (i.e., they log flight hours in military aircraft as a crewmember), but are not required to be rated or licensed pilots, naval flight officers, or navigators/CSOs. They may be called upon to provide medical consultation as members of an investigation board into a military or NASA aviation or spaceflight mishap. Occasionally, they may serve to provide in-flight care to patients being evacuated via aeromedical evacuation, either fixed wing or rotary wing.