If you see movies about aircraft emergencies a large part of them has to do with ATC and in most movies they get the system completely wrong. In this article I will give you a brief description of how the ATC system works. To do this we will come up with a flight to follow.
Our flight will be American Airlines flight 1024 with service from KDFW to KABQ. The first thing to note is that this flight will be given a callsign that it will use to identify itself throughout the flight. In the case of American Airlines they just have the callsign American. Here are some other airline callsigns:
Southwest Airlines: Southwest British Airways: Speedbird Express Jet: Acey
Airlines are allowed to choose their callsign as long as it works with FAA regulations. Anyway, lets get back to our flight. American Airlines 1024 will identify itself as “American 1024” to ATC for the duration of the flight. One of the first things the pilots will do when they get to the aircraft is check the weather and file their get clearance for their flight plan. To check the weather they will use what is called ATIS which stands for Automatic Terminal Information service. When they tune the ATIS frequency into their radio they will get a short automated weather briefing and will also get information on things that are going on at the airport that could directly effect the flight like taxiway closures.
After or sometimes before getting the weather from ATIS they will get cleared for their flight plan using the clearance and delivery frequency. This is where the flight will get cleared to go to their destination using their filed flight plan. This normally does not take but a minute or two but pilots can receive allot of information upon getting their clearance.
Let’s fast-foreword 30 minutes and assume our aircraft has pushed back from the gate and that the engines have been started. The pilots will contact ground. Ground is in charge of all taxiing and and other operations that occur on the ground. Ground will tell the pilots which runway to taxi to and which taxiways to use to get there. The pilots will use charts or maps of the airport to find their way around and get to the runway.
Once the aircraft has made it to the hold short point (which is the area where the taxi way turns into the runway) they will tune and contact the tower frequency. The tower controllers manage traffic near the airport. The area the tower controllers are in charge of depends on the airport and many other factors. Tower will clear American 1024 for takeoff and the flight will be on its way. After leaving the tower airspace American 1024 will be handed off to Dallas departure who will keep aircraft separated and will allow the aircraft to climb.
After getting away from the busy Dallas airspace American 1024 will contact the center frequency who will assign altitudes headings and keep the thousands of aircraft in the air separated. The aircraft will move through the various sectors of the center airspace throughout cruise and descent. As the aircraft gets lower it will contact Albuquerque Approach who will give the aircraft an assigned approach to the airport. About 5-10 miles away from the airport American 1024 will be handed off to the tower in Albuquerque who will clear the flight to land. After landing the aircraft will be handed off to ground who will give the aircraft a taxi route to a gate specified by the airline. The ATC system keeps thousands of people safe at a time and is incredibly effective and efficient.