What is air traffic control – a controller’s perspective

Shailendra Pandaram – “Panda” to his teammates – has worked for Airways as an air traffic controller for 20 years. These days, he’s a team leader, managing Airways’ enroute controllers.
I’m an air traffic controller – so when I meet someone for the first time, a familiar blank look slips across their face. Only 350 people across this country are qualified to do this job, so it’s no wonder really.

Often, people think that I’m from the crew on the runway waving those ping pong paddles at the pilot.

Or that I’m that guy in the movies, leaping up and screaming at aircraft on my walkie talkie.

Sam - radar centreIt comes as a surprise, then, when they find out that my working environment is about as calm and serene as it gets – in fact it looks a bit more like this:

Do you want to know what air traffic control really is?

When it gets back to basics, air traffic control is about preventing collisions between aircraft. We do that – that’s our raison d'être, our lifeblood.

These days, however, we do more than just keep those aircraft a fair distance from each other. We have technologies that help us expedite the traffic flow and provide efficiencies on the tarmac and in the skies.

This is where it gets interesting. Those ears at the party prick up. Last time you boarded an aircraft, did you give any thought to the air traffic controller giving your flight clearance to depart?

Chances are we also cleared the way for your aircraft to arrive a few minutes early, or to ascend a little higher than planned to avoid that spot of turbulence.

An unspilt coffee? A few extra minutes with the kids? More than likely, your airline has kept your ticket prices at an affordable level because of the efficiencies brought about by effective air traffic control.

Less airborne holding and more direct flight paths mean reduced fuel burn and fewer CO2 emissions. Good for passengers, good for airlines and pretty good for our planet too.

Let me explain some of the intricacies of air traffic control

Think of the skies above us as an invisible motorway system, and aircraft as the cars on the road, with a series of air traffic controllers responsible for every stage of the journey.

My tower controller colleagues have the job of directing the aircraft out of the garage, through the city streets (and past the guy mowing the airfield grass, for instance) and onto the motorway. From their eagle perch at the top of the airport’s control tower, they have visibility of each aircraft movement, as well as radar imagery of approaching and departing aircraft.

The tower controller then hands the flight over to me. I’m a radar controller, based at Airways’ radar centre in suburban Christchurch. Using radar systems, I keep an eye on the aircraft and its proximity to other aircraft as they travel along that ‘motorway’. We divide this role up between three radar controllers – one handing the departing aircraft as it climbs, an area controller taking care of the aircraft ‘en route’, and another managing the descent towards the destination airport.

We also have Oceanic controllers, working out of our Auckland radar centre. They look after aircraft as they head out of (and into) New Zealand, and around the top of the North Island.

Take a look at who’s in control for each stage of flight.

Usually, aircraft fly on predetermined ‘tracks in the sky’. Airways has set these tracks using our very smart Performance Based Navigation technology.

That all sounds a bit simple, and there would be more cups of tea on the job if that was all there was to it.

Of course, there are things like adverse weather to keep us on our toes – and this is New Zealand, a long and narrow island nation, so we have plenty of weather, not to mention many significant mountain ranges.

So, as a radar controller, I guide the aircraft around these obstacles. If one aircraft needs to ascend to avoid a storm system, I also make sure that other aircraft in the vicinity correspondingly alter their course so they maintain their separation from it.

Once the flight reaches the zone around the destination airport, another tower controller takes over, guiding the aircraft in to land and to its gate.

How do we know just where that aircraft is?

Air traffic control is for aircraft flying in ‘controlled airspace’. Commercial aircraft, of course, fly in controlled airspace most of the time – that’s your route from Auckland to Wellington, for example, flown dozens of times a day by Air New Zealand and Jetstar.

There are thousands of other aircraft flying in the New Zealand skies every day. From medical personnel on a rescue helicopter to a farming couple popping up the coast to visit some friends, there are a wide variety of reasons for aircraft to be in the skies.

Flying in controlled airspace requires pilots to gain approval from air traffic control. Once in, our controllers become responsible for ensuring the aircraft is where it should be – sort of like an insurance policy.

It is not a requirement to log a flight plan with Airways when flying outside of controlled airspace, but we do recommend it. I think it’s a bit like travelling without insurance, providing that peace of mind that if something does go wrong, we’re looking out for you. Our Flight Service people take care of these flight plans – called Visual Flight Rules – it’s all about making sure that people are reassured and safe.

More than a sixth sense – using radar to track aircraft

These days, most of New Zealand has the benefit of radar air traffic control coverage. The radar system brings some excellent efficiency, allowing us to reduce aircraft separation to between three and five nautical miles. Reduced separation means more aircraft can fit into the airspace, which is especially valuable at our major airports.

Air traffic controllers are trained in both radar and procedural control.

Procedural approach systems require the controller to use flight progress strips to build a 3D picture in his or her mind. This is where the very specific requirements for this job become apparent – you need a very strong suite in spatial awareness to be able to do this. We apply the correct separation levels based on the aircraft’s position reports and altitude, gained from flight plans and from talking with the pilot in flight.

Regardless of whether we are using a radar or a procedural system, everything we do is backed up on paper based flight progress strips.

Before the beginning of the flight, the pilot informs air traffic control of the flight plan. This information is noted both on our computer system and on the flight progress strips, and any deviations in flight are replicated by writing on the strips.

Ensuring safety in the skies – contingencies for every circumstance

Flight progress strips are just one of the many contingencies we have in place. As I said earlier, safety is everything, and so we have backups for everything we do.

Obviously, we need our radar screens and all of our technical equipment to be available 24/7, so we have uninterrupted power supply systems in all of our air traffic control centres. There is no downtime in a power failure situation, and we have alternative feeds for all of our radars to make sure that we are not reliant on any one point of the system.

Each of our buildings has a contingency alternative, and we can immediately transfer to another centre if it comes to it, as we did during the Christchurch earthquake sequence.

Because of the intricacies of each air traffic control area, we can’t just switch staff around between towers or radar centres. It’s not as simple as calling in some temps – we operate on a licence system which is all approved by the International Civil Aviation Organisation (ICAO).

Only around 3% of the population have what it takes to become an air traffic controller, and training takes over two years after selection. It takes around six months for a controller to get ‘rated’ or certified to work on a particular airspace, so we have to ensure that we have sufficient staff available all of the time. As a very last resort in an emergency situation, we have the ability to cease all departing flights and bring all flying aircraft to the ground immediately and safely.

Did I mention the Queen?

As you can see, this is a challenging job with more than a little responsibility involved.

Planes don’t keep business hours, so there is middle of the night work, public holiday work, early in the morning work. And keeping my air traffic controller certification requires ongoing study, pilot-standard medicals, and certification reassessments after breaks of any more than a month.

But there is just something about it that makes me get up in the morning (or in the middle of the night).

Perhaps it was the time I goaded my colleague into standing to attention when he was controlling the Queen’s aircraft. Perhaps it was the buzz of guiding the Concorde out of New Zealand airspace. Or humming along while U2’s aircraft took off under my control.

We are a bunch of plane spotters, many of us with our own pilot’s licence, and we manage to conjure up a pretty amicable working environment. There is something about being a little bit invisible, being in the background, ensuring passengers are getting to their destinations safety.

We take our work very seriously, and the satisfaction of a job well done is instantaneous.