After hours of routine operations, an air traffic controller gets a radio call from a small aircraft whose cockpit indicators can’t confirm that the plane’s landing gear is prolonged for landing. The controller arranges for the pilot to fly low by the tower so the controller can visually check the plane’s landing gear. All appears well. “It looks like your gear is down,” the controller tells the pilot.

The controller calls for the airport fire trucks to be ready just in case, and the aircraft circles back to land safely. Scenarios like this play out often. In the air traffic control system, every part must meet the very best levels of safety, but not every part goes based on plan.

Contrast this with the still science-fiction vision of future artificial intelligence “pilots” flying autonomous aircraft, complete with an autonomous air traffic control system handling aircraft as easily as routers shuttling data packets on the web.

I’m an aerospace engineer who led a National Academies study ordered by Congress about air traffic controller staffing. Researchers are continually working on recent technologies that automate elements of the air traffic control system, but technology can execute only those functions which might be planned for during its design and so can’t modify standard procedures. As the scenario above illustrates, humans are prone to remain a obligatory central component of air traffic control for a very long time to return.

What air traffic controllers do

The Federal Aviation Administration’s fundamental guidance for the responsibility of air traffic controllers states: “The primary purpose of the air traffic control system is to stop a collision involving aircraft.” Air traffic controllers are also charged with providing “a secure, orderly and expeditious flow of air traffic” and other services supporting safety, akin to helping pilots avoid mountains and other hazardous terrain and unsafe weather, to the extent they’ll.

Air traffic controllers’ jobs vary. Tower controllers provide the local control that clears aircraft to take off and land, ensuring that they’re spaced safely apart. They also provide ground control, directing aircraft to taxi and notifying pilots of flight plans and potential safety concerns on that day before flight. Tower controllers are aided by some displays but mostly look outside from the towers and talk with pilots via radio. At larger airports staffed by FAA controllers, surface surveillance displays show controllers the aircraft and other vehicles on the bottom on the airfield.

This FAA animation explains the three basic components of the U.S. air traffic control system.

Approach and en route controllers, however, sit in front of huge displays in dark and quiet rooms. They communicate with pilots via radio. Their displays show aircraft locations on a map view with key features of the airspace boundaries and routes.

The 21 en route control centers within the U.S. manage traffic that’s between and above airports and thus typically flying at higher speeds and altitudes.

Controllers at approach control facilities transition departing aircraft from local control after takeoff up and into en route airspace. They similarly take arriving aircraft from en route airspace, line them up with the landing approach and hand them off to tower controllers.

A controller at each display manages all of the traffic inside a sector. Sectors can vary in size from just a few cubic miles, focused on sequencing aircraft landing at a busy airport, to en route sectors spanning greater than 30,000 cubic miles (125,045 cubic km) where and when there are few aircraft flying. If a sector gets busy, a second and even third controller might assist, or the sector is likely to be split into two, with one other display and controller team managing the second.

How technology might help

Air traffic controllers have a stressful job and are subject to fatigue and data overload. Public concern a couple of growing variety of close calls have put a highlight on aging technology and staffing shortages which have led to air traffic controllers working mandatory time beyond regulation. New technologies might help alleviate those issues.

The air traffic control system is incorporating recent technologies in several ways. The FAA’s NextGen air transportation system initiative is providing controllers with more – and more accurate – information.

Controllers’ displays originally showed only radar tracking. They now can tap into all the information known about each flight throughout the en route automation modernization system. This system integrates radar, automatic position reports from aircraft via automatic dependent surveillance-broadcast, weather reports, flight plans and flight histories.

Systems help alert controllers to potential conflicts between aircraft, or aircraft which might be too near high ground or structures, and supply suggestions to controllers to sequence aircraft into smooth traffic flows. In testimony to the U.S. Senate on Nov. 9, 2023, about airport safety, FAA Chief Operating Officer Timothy Arel said that the administration is developing or improving several air traffic control systems.

Researchers are using machine learning to research and predict facets of air traffic and air traffic control, including air traffic flow between cities and air traffic controller behavior.

How technology can complicate matters

New technology may also cause profound changes to air traffic control in the shape of recent sorts of aircraft. For example, current regulations mostly limit uncrewed aircraft to fly lower than 400 feet (122 meters) above ground and away from airports. These are drones utilized by first responders, news organizations, surveyors, delivery services and hobbyists.

NASA and the FAA are leading the event of a traffic control system for drones and other uncrewed aircraft.

However, some emerging uncrewed aircraft firms are proposing to fly in controlled airspace. Some plan to have their aircraft fly regular flight routes and interact normally with air traffic controllers via voice radio. These include Reliable Robotics and Xwing, that are individually working to automate the Cessna Caravan, a small cargo airplane.

Others are targeting recent business models, akin to advanced air mobility, the concept of small, highly automated electric aircraft – electric air taxis, for instance. These would require dramatically different routes and procedures for handling air traffic.

Expect the unexpected

An air traffic controller’s routine may be disrupted by an aircraft that requires special handling. This could range from an emergency to priority handling of medical flights or Air Force One. Controllers are given the responsibility and the pliability to adapt how they manage their airspace.

The requirements for the front line of air traffic control are a poor match for AI’s capabilities. People expect air traffic to proceed to be the safest complex, high-technology system ever. It achieves this standard by adhering to procedures when practical, which is something AI can do, and by adapting and exercising logic every time something unplanned occurs or a brand new operation is implemented – a notable weakness of today’s AI.

Indeed, it’s when conditions are the worst – when controllers determine how one can handle aircraft with severe problems, airport crises or widespread airspace closures because of security concerns or infrastructure failures – that controllers’ contributions to safety are the best.

Also, controllers don’t fly the aircraft. They communicate and interact with others to guide the aircraft, and so their responsibility is fundamentally to function a part of a team – one other notable weakness of AI.

As an engineer and designer, I’m most excited concerning the potential for AI to research the large data records of past air traffic operations in pursuit of, for instance, more efficient routes of flight. However, as a pilot, I’m glad to listen to a controller’s calm voice on the radio helping me land quickly and safely should I actually have an issue.

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