How many atc centers are there

They must file flight plans and are serviced by the mainstream air traffic control system. Your flight, like every other commercial airline flight, follows a typical profile:. While you prepare for your flight by checking your bags and walking to the gate, your pilot inspects your plane and files a flight plan with the tower -- all IFR pilots must file a flight plan at least 30 minutes prior to pushing back from the gate.

Your pilot reviews the weather along the intended route, maps the route and files the plan. The flight plan includes:. In the tower, a controller called a flight data person reviews the weather and flight-plan information and enters the flight plan into the FAA host computer. The computer generates a flight progress strip that will be passed from controller to controller throughout your flight.

The flight progress strip contains all of the necessary data for tracking your plane during its flight and is constantly updated. Once the flight plan has been approved, the flight data person gives clearance to your pilot clearance delivery and passes the strip to the ground controller in the tower. The ground controller is responsible for all ground traffic, which includes aircraft taxiing from the gates to takeoff runways and from landing runways to the gates. When the ground controller determines that it is safe, he or she directs your pilot to push the plane back from the gate airline personnel operate the tugs that actually push the aircraft back and direct the plane out of the gate area.

As your plane taxis to the runway, the ground controller watches all of the airport's taxiways and uses ground radar to track all of the aircraft especially useful in bad weather , ensuring that your plane does not cross an active runway or interfere with ground vehicles. The ground controller talks with your pilot by radio and gives him instructions, such as which way to taxi and which runway to go to for takeoff. Once your plane reaches the designated takeoff runway, the ground controller passes the strip to the local controller.

The local controller in the tower watches the skies above the airfield and uses surface radar to track aircraft. He or she is responsible for maintaining safe distances between planes as they take off. The local controller gives your pilot final clearance for takeoff when it is deemed safe, and provides the new radio frequency for the departure controller.

Once clearance is given, your pilot must decide if it is safe to take off. If it is safe, he accelerates the plane down the runway. As you leave the ground, the local controller hands your plane off electronically to the departure controller at the TRACON facility that services your departure airport, but still monitors the plane until it is 5 miles from the airport.

Your pilot now talks with the departure controller. Once your plane takes off, your pilot activates a transponder device inside the aircraft. The transponder detects incoming radar signals and broadcasts an amplified, encoded radio signal in the direction of the detected radar wave.

The transponder signal provides the controller with your aircraft's flight number, altitude, airspeed and destination. A blip representing the airplane appears on the controller's radar screen with this information beside it.

The controller can now follow your plane. He or she uses radar to monitor the aircraft and must maintain safe distances between ascending aircraft. The departure controller gives instructions to your pilot heading, speed, rate of ascent to follow regular ascent corridors through the TRACON airspace.

The departure controller monitors your flight during ascent to the en route portion. Every time your plane gets passed between controllers, an updated flight progress slip gets printed and distributed to the new controller. The radar associate controller receives the flight-plan information anywhere from five to 30 minutes prior to your plane entering that sector.

The associate controller works with the radar controller in charge of that sector. The center controllers provide your pilot with updated weather and air-traffic information. They also give directions to your pilot regarding such aspects as speed and altitude to maintain a safe separation between aircraft within their sector.

They monitor your plane until it leaves their sector. Then they pass it off to another sector's controller. Another controller, called the radar hand-off controller , assists the radar and associate radar controllers during times of heavy traffic, watching the radar screen and helping to maintain smooth air-traffic flow.

While you are enjoying your meal, snack, in-flight movie or the view outside the window, your plane gets passed from sector to sector and center to center.

In each sector, center controllers radio instructions to the pilots. During most daylight hours there will always be a second person assigned to each sector whose function is principally communications and computer input.

While the Radar controller is talking to the aircraft, the D-Side Data controller is coordinating with all the surrounding sectors and facilities. For instance, an aircraft requests descent to another altitude. Early knowledge of how many aircraft and what pathways they are flying provide the sector controllers opportunity to mitigate problems before they arise.

Really busy sectors and times of day may necessitate a third controller who stands behind the other two providing another set of eyes. This person makes coordination calls as needed.

In addition to actively controlling the aircraft, controllers take PIREPS about flight conditions and weather reports and pass them to their Flight Data Assistants to be entered into the national weather service database. They coordinate non-control information with other air traffic facilities, such as parachute jumping activity to assure the appropriate sectors are aware of when and where this will take place.

During times of light traffic— such as during midnight shifts— one person may handle all the duties for several combined sectors. The Flight Data assistants determine which sectors or staff could be affected by the information and distribute it accordingly.

They also track flight planned proposal times of aircraft wanting to join the dance aloft. If projected volume exceeds established parameters, or if weather causes difficulties in certain areas, the Flow controllers initiate departure or arrival delays. The aircraft show up as small arrow like icons with data blocks appended. Controllers can extend a line forward along the route of the aircraft to see if it will conflict with other aircraft.

As the aircraft approaches the invisible boundary of Approach airspace, the computer screen starts flashing its data block on the display to alert the controller. Simultaneously the equipment at the sector receiving the aircraft will pick up the signal and flash to alert that controller of an incoming aircraft.

If no further coordination is required, the incoming sector controller keys the accept key and the outgoing sector controller instructs the pilot to change frequencies. If the sector controller sees a problem with the aircraft approaching his airspace he calls the controller currently handling the aircraft to have it put on an alternate heading or altitude before it enters his airspace.

Only after this change is made will the incoming controller accept the handoff. Fort Worth sees the aircraft handoff, but has traffic at FL Once Fort Worth sees the altitude information in the data block has been changed to reflect the new clearance altitude, they accept the handoff.

Fort Worth will allow the air carrier to continue the climb once the conflicting aircraft is no longer a factor. Similarly, when handing the aircraft off to an approach control, the data block will flash H for handoff plus the ID for that facility. The further ahead an action can be taken to avoid aircraft coming into conflict, the easier it is on the pilots.

For instance, if the computer shows a potential conflict miles from the conflict point, one or both aircraft may be asked to alter their heading by only five degrees, then be set on course once the required separation is achieved. Log In Sign In. Forgot password? Enter your account data and we will send you a link to reset your password.

Your password reset link appears to be invalid or expired. Log in Privacy Policy To use social login you have to agree with the storage and handling of your data by this website. Add to Collection Add new or search Public collection title. Private collection title. This is independent of ATC and it's designed to warn pilots and prevent midair collisions. There's also newer ATC technology, called NextGen, which uses both radar and satellite-based technology, " an "attempt to move the FAA out of 's methodology of aircraft separation.

Air traffic controllers are glued to a screen and never see the aircraft they're working with. It's true that air traffic controllers monitor radar screens to track aircraft. As aircraft fly over radar sites, the data from those radars is communicated digitally via telecommunications lines to controllers hundreds or even thousands of miles away. But Sully says that many people imagine that an ATC center is like something out of CSI , showing highly advanced graphic displays in real time.

The reality is that the technology in use today is older and is not yet as good as depicted in movies and television. It's a two-prong system: Radar controllers may be watching blips on a screen, but tower controllers, if the weather is good, are watching the actual aircraft.

Air traffic controllers, says Sully rely on good training and judgment and "good human performance. Automation will not do everything for us. As long as aircraft are safely landing and taking off, air traffic controllers have done their job. At larger airports, ATC is responsible for all movements and for making sure that not only aircraft but airport vehicles are doing what they are assigned to do on specific routes.