Safe skies

A look at the Winnipeg Area Control Centre

navcanFrom the moment your flight departs Winnipeg Richardson International Airport until it lands at its final destination, it is being tracked by a dedicated corps of air traffic controllers (ATC) working at control facilities across the country.

While many travellers are familiar with the control towers that stand tall over the country’s busiest airports, there is another type of facility that plays a key role in making sure aircraft keep moving safely and efficiently.

Enter the Winnipeg Area Control Centre (ACC), one of seven facilities in Canada responsible for large sections of airspace.

Unlike their fellow controllers located in control towers who have a direct view of runways and the airspace around the airport, these professionals do their job in an enclosed operations room – using powerful flight data processors, state-of-the art surveillance displays and communications systems to help keep aircraft moving on course and on time in a complex 24/7 operation.

The centre is run by experts that have completed an intensive training program that includes classroom, simulator and on-the-job training and takes roughly two years to complete.

navcan2The operations room
The operations room is dimmed and surprisingly quiet as approximately 20 controllers sit at consoles outfitted with several large screens that display aircraft targets, special operational information, weather information and a communications panel. The shift manager sits at the front of the room with screens monitoring the entire operations room and overseeing the airspace Winnipeg’s centre is responsible for – known as the Winnipeg Flight Information Region.

High altitude controllers line one wall, while low altitude controllers line the wall opposite them. Terminal controllers work on the far side of the room and the middle is filled with supervisors’ desks. It is a beehive of activity, but it is a quiet concentrated work environment.

Each controller is responsible for a sector of airspace and has been trained for that specific geographical location as well as an altitude range (high, low or terminal). As pilots pass through a sector of airspace, they are required to check in with the controller responsible for that airspace. This can include passenger airlines, cargo carriers, private operators, emergency services like medevac, and others.

Pilots count on the controller’s directions to fly safely and maintain a safe distance from other aircraft. Air traffic controllers also provide pilots with critical flight information, such as weather, information regarding turbulence, airport advisories and many other services. The controllers ensure aircraft separation by communicating via radio and data link commands.

High altitude air traffic control
navcan3These controllers are trained to work high altitude sectors – 29,000 feet and above. They use a computerized flight data system – CAATS (short for the Canadian Automated Air Traffic System) – and will speak over a radio frequency or use controller-pilot data link communications (CPDLC), which allows controllers and pilots to text each other.

Using these systems, controllers monitor flights in order to ensure a minimum distance of five nautical miles laterally or 1,000 feet vertically between aircraft. Controllers use their airspace knowledge, established procedures and conflict detection tools to identify if a change of course, altitude or speed is required to maintain the proper distance.

High altitude controllers also let pilots know about turbulence − how large of an area is affected and if they can make the ride more comfortable for passengers by climbing or descending. They will warn pilots if they should expect wake turbulence (air currents behind an aircraft much like the wake in the water behind a boat) from other planes or if they will need to avoid military airspace.

In addition to watching their own airspace, controllers work with controllers responsible for neighbouring airspace sectors. If they anticipate a possible conflict in their neighbour’s airspace they will work together to resolve it well in advance.

The greatest portion of high level traffic flies between 34,000 and 39,000 feet, a range filled mostly with airliners and cargo planes at cruising altitude. Using the plotted points of a flight plan, controllers employ the computer system to calculate each flight’s anticipated time of arrival at various points along their route, ensuring there are no overlaps with other aircraft.

Technology investment has led to improved service. Planes used to use actual “highways” flying from one waypoint to the next, mapped out in the sky and supported by a network of ground-based navigational aids. Today they plot courses with GPS to get more direct routes, which results in shorter flight times and fuel cost savings.

The EXCDS (Extended Computer Display System) uses electronic versions of paper flight strips which are displayed on a computer screen along with paper strips. Each flight strip – paper or digital – represents one aircraft. These strips contain all the data on the flight to allow the controller to plan separation and calculate estimates.

Low altitude sectors
Air traffic controllers working in low altitude sectors are trained to monitor flights below 29,000 feet. This traffic can include some commercial flights as they ascend to their cruising altitude, or descend to their destination as well as medevacs and emergency aircraft, providing this sector with a good mix of large and small traffic.

Low altitude sectors will include many aircraft using visual flight rules or VFR. Controllers will not normally speak with these aircraft, but will communicate with all planes operating with Instrument Flight Rules and advise them of any known VFR aircraft.

Winnipeg terminal air traffic controller
This can be one of the busiest sectors to work as these controllers are responsible for lining up flights in preparation for landing and sorting the flows to various destinations after their departures. They work a 35-mile radius surrounding the Winnipeg airport, stretching 55 miles to the west of the airport in order to provide service over Portage airport. Terminal controllers are trained to line up arrivals prior to handing them off to the tower, or in the case of departing aircraft, to take them over from the tower once the plane has reached 3,000 feet.

In this sector, controllers maintain a minimum separation standard between aircraft of three nautical miles and 1,000 feet. Arrival sequencing is determined based on the speed and location of incoming flights.

Controllers give pilots crucial information on landing/runway conditions, cloud ceiling levels, expected wake turbulence from other aircraft, weather, wind, altimeter readings and more. The sky surrounding the airport is set up in a grid with phantom arrival and departure gates that controllers will guide flights through to ensure separation. In order to ease coordination with the tower, the EXCDS program is used to seamlessly communicate between controllers.

The professionals at the Winnipeg area control centre are a great example of some of the dedicated and focused people working behind the scenes, to move a flight from departure to destination. Together, they play a key role delivering on NAV CANADA’s primary purpose – the safety of aircraft flying in Canadian airspace.

Special thanks to Terry Ferguson, Diana Kelly, Kim Grant, Matt Sharp, Dave Maclennan, and Gord Kempe of NAV CANADA.