How the Federal Aviation Administration (FAA) Works

美国联邦航空局的安全是最重要的工作。FAA ensures that aircraft are safe to fly, that pilots and mechanics are qualified, and that the people and systems that regulate the flow of air traffic do so safely.

One big part of safety is making sure that planes don't run into each other when they are in the air. TheNational Airspace System(NAS) is a complex system made up of the people, equipment and systems that monitor every plane in the air over the United States and large parts of the world's oceans at any given moment. The NAS oversees both U.S. civilian and commercial aviation and provides traffic control for military craft flying over domestic airspace. This is a huge task - according to the FAA, an average of 50,000 flights use the NAS each day. In 2006, theAir Route Traffic Control Centers(ARTCCs) routed more than 46 million flights [source:FAA Administrator's Fact Book].

When an aircraft is at an airport, it is managed by anairport traffic control tower(ATCT). The ATCT is located at the airport and handles the departures and arrivals of aircraft at that particular airport. Large airports, such as Dallas-Fort Worth, may have more than one ATCT due to their size and volume of traffic.

Once the plane has departed and is five miles from the airport, the ATCT hands it off to localterminal radar approach control (TRACON)facilities. A TRACON is normally the "middleman," managing the airspace around major metropolitan areas, generally within a 30- to 50-mile radius and under 10,000 feet [source:FAA TRACON fact sheet]. Once the aircraft leaves that zone, the plane enters what the FAA calls "en route airspace," and the TRACON hands the aircraft off to the regional ARTCC. However, if the aircraft is small and stays below 10,000 feet throughout the flight, the TRACON handles the entire flight.

航线是空域管理的核心。在那里are 22 ARTCCs, each of which is responsible for an area of airspace defined by the FAA. Next, we'll learn how ARTCCs operate.

Photo Courtesy Federal Aviation Administration (FAA) Southern California TRACON at San Diego, California

Occasionally, an aircraft never leaves the airspace of a single control center, as is often the case with commuter flights. Usually, however, the aircraft's destination is in the jurisdiction of another ARTCC. In this case, the first ARTCC hands the aircraft off to the next ARTCC as it leaves the first ARTCC's airspace. The plane goes from one traffic control center to the next, until it reaches the boundaries of the destination ARTCC.

As an aircraft approaches its destination, the departure hand-off sequence is simply reversed. The regional ARTCC of the destination airport hands the aircraft off to the local TRACON, which guides the aircraft into the airport. As the aircraft prepares for final approach, the TRACON hands the aircraft off to the airport's ATCT. The ATCT guides the aircraft in for landing and tells it when it can go to the appropriate gate so the passengers can disembark.

In addition to the in-flight management provided by the facilities discussed above, the FAA operatesflight service stations(FSS), centers where pilots submit flight plans and receive information about the weather and any other conditions that might affect their flight. Each FSS broadcasts weather, emergency and navigation information and advisories, and coordinates search-and-rescue efforts.

In the next section, we will talk about how the FAA provides safety regulations and licensing.

Photo courtesyNASA Commercial space launches are primarily used to place communicationssatellitesin orbit.

The primary regulation of airspace occurs through the air traffic management system discussed in the previous section.Air traffic controllersfollow guidelines established by the FAA for everything from the distance between aircraft to theradio frequenciesthey use to communicate.

In the United States, the FAA is responsible forlicensing几乎所有有关航空航天,including commercial space operations. There are 10 commercial space launches planned for 2007 [source:FAA Administrator's Fact Book].

The aerospace areas licensed or certified by the FAA include:

• Personnel (pilots, instructors, engineers, mechanics, air traffic controllers)
• Aircraft
• Airlines
• Airports
• Air traffic management facilities
• Commercial air freight facilities
• Commercial space launch facilities
• Commercial space vehicles

To be licensed, a person, place or object must meet the requirements set forth by the FAA to operate according to the rules of that particular license. For example, a pilot may receive avisual flight rules(VFR) license that allows him to operate an aircraft flying under 18,000 feet (5 486.4 meters), but the lowerst cloud layer cannot be lower than 1,000 feet (304.8 meters) and visibility must be 3 miles (4.8 km) or better. Unless the pilot gets aninstrument flight rules(IFR) license, he may not pilot an aircraft flying above 3,000 feet or in reduced visibility.

FAA expects that there will be more than 230,000 active aircraft in the United States by 2009 and that the ARTCCs will be routing more than 50 million flights that year [source:FAA Administrator's Fact Book]. With so much traffic in the air, safety is a major concern. The FAA sets safety standards for all facets of aviation, from the equipment and structure of the aircraft to the amount of fatigue or stress that the pilot can endure in a work shift.

FAA has the authority togroundapilot, an aircraft or an entireairline如果觉得有合理怀疑,the ability of that entity to operate safely. "Grounding" means that a person or craft cannot fly until the FAA provides clearance to do so. For example, if an airline has a couple of planes that fail inspection, the FAA has the authority to ground the entire airline until the agency is assured that everything is in compliance.

Although the FAA ensures air travel safety, the agency does not look into the causes of plane crashes. TheNational Transportation Safety Board(NTSB) is the independent federal agency that investigates all transportation-related accidents. You can learn more about the NTSB in the articleHow Black Boxes Work.

According to theFAA Administrator's Fact Book, there were 616 aviation-related fatalities in the United States in 2005. Let's compare that to the other forms of transportation:

In 2005, even boating and train accidents claimed more lives than aircraft accidents. Statistically speaking, flying is safer than driving, yet most people who are afraid to fly don't think twice about hopping in their car or truck.

FAA is constantly researching, developing and implementing new programs, technologies and methods that will improve aviation. Of the organization's $8.4-billion budget for 2007, $130 million has been allocated for research and development [source:FAA Administrator's Fact Book]. The FAA even has several sub-organizations dedicated to research and development, such as theOffice of Aviation Research.

The key areas of FAA research include:

Photo courtesy Federal Aviation Administration (FAA) Host and Oceanic System Replacement (HOCSR)

• Aviation weather
• Navigation systems
• Aircraft noise pollution
• Airport security
• Energy conservation
• Aviation technology
• Satellite technology
• Surveillance systems
• Communications systems
• Landing systems
• Systems science
• Commercial space transportation

The photo above is an example of the type of research conducted by the FAA. In this photo, you see theHost and Oceanic System Replacement(HOCSR), a very powerful computer system used in the ARTCCs [source:FAA press release]. HOCSR is a development system used to field-test various programs designed to enhance the speed and safety of aircraft.

The main FAA research facility is theWilliam J. Hughes Technical Center, where around 150 research programs are in development at any given time. The center is also home to security initiatives including the Federal Air Marshal Program, the Transportation Security Laboratory andAviation Security Research and Development(AAR-500). A key part of AAR-500's mission is to anticipate future threats to U.S. aviation. As part of AAR-500, theAviation Security Laboratorydevelops preventative measures and countermeasures for such threats.

• Explosives and weapons detection
• Aircraft hardening
• Human factors
• Airport security technology integration

To improve safety and security for air travel passengers, the FAA, theJoint Planning and Development Office, and other agencies are currently upgrading the air traffic management system with satellite technology and advanced networking to improve air management control. The improved system will allow an increase in system capacity with fewer delays and bottlenecks. Check out the links below for comprehensive information on some of the FAA's research and development programs:

• National Aviation Research Plan
• Air Traffic Systems Development
• Airport Safety and Certification
• William J. Hughes Technical Center
• Office of Aviation Research

For more information on the FAA, aviation and airports, see the links on the following page.