Fresh off International Air Traffic Controllers' Day, we thought we’d take a look into how air traffic control (ATC) actually works. There’s plenty to consider when it comes to the management of the complex processes involved.

Covering ground

Different regions have different names for the departments involved in air operations. For instance, United States airspace is divided up into 21 separate zones, and each is then split further into sectors. There are pockets of airspace in each zone that have a diameter of approximately 80 kilometers (50 miles). These are called Terminal Radar Approach Controls (TRACON).

Altogether, the Federal Aviation Administration (FAA) has formed the US air traffic control system around these divisions. As such, there are numerous workers within the process that are signed to specific zones.

So, the handling of aircraft departing and approaching particular airspace in the US is overseen by TRACON. However, all air traffic control is the responsibility of the Air Traffic Control System Command Center (ATCSCC). Additionally, the Air Route Traffic Control Centers (ARTCC) handle traffic within all the sectors of its center.

Despite the departments varying, the universal approach is similar. Departments work together to offer robust air traffic control.

Generally, prior to takeoff, carriers would submit a flight plan with ATC to ensure that every controller involved knows about the details of the complete journey. Subsequently, the pilots managing the aircraft at an airport will be in touch with local controllers in the tower. ATC would then look after the vessel while it is at the airport and give it the go-ahead to take off.

Close communication

Once in the air, the pilot would usually speak with another controller utilizing a radar screen to track the plane's progress through the airways system, which is dubbed as the sky's version of a freeway.

The United Kingdom’s Civil Aviation Authority (CAA) states:

“Each controller is responsible for aircraft in a set piece of airspace. When an aircraft is nearing the edge of their sector they will coordinate its handover to the next controller. This will continue through the aircraft’s journey until it is handed over to the controller at the destination airport. Most airliners are monitored by controllers using radar in airways and routes known as ‘controlled airspace’.

“The majority of airspace that is left is known as ‘uncontrolled’ and this is used by the military and recreational pilots. In this airspace some air traffic control services are provided, especially near airfields, but in much of the airspace it is the pilots’ responsibility to see and avoid each other.”

Get the latest aviation news straight to your inbox: Sign up for our newsletters today.

Safe and secure

Controllers use transponders, which deliver a response when they obtain a radio-frequency interrogation, to help identify planes on a radar spoke and additional collision avoidance devices. There have been many instances of ATC being quick to address emergencies, such as engine failure, to help pilots land without tragedy.

New Delhi Air Traffic Control
Photo: Getty Images

All in all, from the flight path to the runway, every factor is already decided beforehand, particularly when it comes to commercial flights. ATC ensures that pilots are sticking to the plan and will be in contact if an aircraft veers off the route.

The ultimate purpose is to avoid collisions and ensure a smooth flow of air traffic for a safe and seamless journey. Some airports go the extra mile and make ATC towers extra tall. After all, these buildings are designed to be high enough for controllers to have an optimal view of the airport environment.

Nonetheless, there has been an emerging trend of remote working in the field, with centers located airway from the airport using modern technology, including an array of cameras feeding information to controllers. ATC also has the potential to improve efficiency and, in turn, reduce emissions.

ATC has been an integral part of airline operations over the decades. Despite the ever-changing conditions of the industry, it will long remain the backbone of the industry.

What are your thoughts about how air traffic control works? What do you make of the overall systems across the globe? Let us know what you think in the comment section.

Source: CAA; IVAO