Flight surgeons are physicians (MDs or DOs) who serve as the primary care physicians for a variety of military aviation personnel on special duty status — e.g., pilots, Flight Officers, navigators/Combat Systems Officers, astronauts, missile combat crews, air traffic controllers, UAV operators and other aircrew members, both officer and enlisted. In the United States Department of Defense, the Army, Navy, and Air Force all train and utilize flight surgeons. In addition to serving as primary care for military members on special duty status and their families, the U.S. Department of Defense uses flight surgeons for a variety of other tasks.