Federal Aviation Administration
Under the U.S. Department of Transportation, the Federal Aviation Administration (FAA) is responsible for the safety of civilian flights. Beginning with the basic licensing of pilots, aircraft mechanics and flight attendants, its authority extends to operating the national air traffic control system. FAA issues "airworthiness certificates" for new aircraft types and major variations, and has the authority, in the case of a potential safety hazard, to ground all aircraft of the type under a certificate. FAA inspectors check on the mechanical safety of commercial aircraft, and conduct or monitor the physical qualifications of flight personnel. They have an active research program in aviation safety.
Accident investigation, to avoid conflict of interest, is under the independent National Transportation Safety Board. The FAA will participate in such investigations as a source of information, especially on air traffic control, just as the airline, the aircraft and engine manufacturers, and other interested parties contribute to investigations.
The FAA is the U.S. government technical representative to the United Nations International Civil Aviation Authority.
While the FAA, especially in supervision of airlines, is involved in airline security, the Transportation Safety Administration, in the U.S. Department of Homeland Security, is responsible for air marshals aboard aircraft, and the security screening of passengers. Most actual screening is done by contractors.