Ever wondered how planes smoothly navigate the skies and avoid mid-air collisions? The answer lies in the highly organised and sometimes secretive world of air traffic control (ATC).

Air traffic controllers are the unsung heroes of aviation, making sure thousands of flights operate safely every day. But what really goes on behind the radar screens? Let’s dive into some fascinating facts and secrets of air traffic control that you probably didn’t know.

1. Air Traffic Controllers Have Intense Training

Becoming an air traffic controller isn’t for the faint-hearted. The rigorous training can take between two and four years, involving classroom learning, simulations, and on-the-job experience. Controllers must have strong communication, multitasking, and problem-solving skills. They’re required to make quick decisions under pressure, and the stakes are high—mistakes could lead to catastrophic consequences.

In the UK and Ireland, trainees start by learning the basics of air traffic, radar systems, and radio communication. As they progress, they’re introduced to real-time simulations and eventually work in a live environment, always under supervision until fully certified.

2. They Speak a Secret Language

While you may hear pilots and air traffic controllers talking in English, they’re actually speaking a specialised, standardised aviation language designed to be clear and concise. ICAO Standard Phraseology, set by the International Civil Aviation Organization, ensures that everyone is on the same page, regardless of nationality or language barriers. For instance, the number 9 is pronounced as “niner” to avoid confusion with the word “five,” and “affirmative” is used instead of “yes” to ensure clarity.

Even the phonetic alphabet (Alpha, Bravo, Charlie) comes into play to spell out locations and other crucial information. Every word has been carefully chosen to prevent miscommunication in noisy or busy airspaces.

3. They Control Every Aspect of a Flight

From the moment your plane leaves the gate to the second it touches down at its destination, it’s under the supervision of multiple air traffic controllers. There are three main phases of control:

• Ground Control: These controllers manage aircraft movement on the airport’s taxiways and runways. They ensure that no planes collide on the ground and that take-offs are timed efficiently.
• Tower Control: Once a plane is ready for take-off, the tower controller gives clearance, monitors the plane’s climb, and hands it off to the next phase of control.
• En-Route Control: Also known as area control, these controllers handle aircraft while they are in the air between airports, monitoring hundreds of planes as they cruise at high altitudes, sometimes miles apart but only separated by a few seconds of timing.

This seamless handover between controllers ensures that each flight is constantly under watch, even if the passengers remain blissfully unaware.

4. There Are ‘Highways’ in the Sky

Just like motorways guide cars on the ground, planes follow specific flight paths called airways. These invisible “highways” in the sky are pre-defined routes that aircraft must follow, dictated by air traffic control to avoid congestion and maintain safe separation.

Depending on wind patterns, airspace restrictions, or traffic, controllers may instruct pilots to change their course, but planes generally stick to these airways for efficiency. Aircraft flying at different altitudes have designated levels to prevent mid-air collisions, and the airspace is divided into sectors, each managed by different controllers.

5. Air Traffic Controllers Use Redundancy for Safety

Air traffic control systems are built with multiple layers of redundancy to prevent failures. Controllers rely on radar systems, GPS, and radio communication to track planes. If one system fails, there are backups in place to ensure the controller remains in constant contact with pilots.

Even the power systems at control towers have backups. In case of a power outage, emergency generators are ready to kick in, ensuring that no flight is left unmonitored.

6. Fatigue is a Major Concern

Air traffic controllers work in highly stressful conditions, often for long hours. Mental fatigue can be dangerous, so regulations in many countries require controllers to work in shifts, with mandatory breaks to maintain sharp focus.

In Ireland and the UK, for example, controllers typically work for 90 minutes followed by a 30-minute break. This is strictly enforced to reduce the risk of errors caused by mental exhaustion.

7. “Ghost Flights” Are a Real Phenomenon

“Ghost flights” refer to planes that controllers can see on their radar screens but don’t actually exist. These glitches are caused by radar systems detecting echoes or other anomalies. While rare, controllers are trained to quickly recognise and dismiss these false alarms, ensuring that real planes receive the attention they need.

8. They Have a Cool-Headed Crisis Mode

When emergencies happen, air traffic controllers are trained to handle them with extreme precision. Whether it’s a technical malfunction, medical emergency, or bad weather, controllers must think quickly and clearly to guide the aircraft to safety. There are specific protocols for dealing with emergencies, and controllers are the key to ensuring pilots receive the information and support they need to manage the situation.