Air navigation service providers (ANSP) in the UK and Canada later this month will start a joint trial of space-based surveillance of aircraft flying over the North Atlantic, a capability that will deliver immediate safety and capacity benefits for oceanic travel.

UK NATS will begin tracking aircraft over the eastern half of the North Atlantic the night of March 27, using the Aireon system of automatic dependent surveillance-broadcast (ADS-B) receivers carried by Iridium Next satellites. This will be the start of a joint operational trial with Nav Canada, which manages the western half of the oceanic airspace.

Using space-based ADS-B, controllers will receive vastly more frequent position updates from aircraft plying the oceanic airspace, allowing them to substantially reduce separations between aircraft on the current track system. Eventually, the track system may be eliminated.

“It’s exciting,” UK NATS operations director Juliet Kennedy told ATW. “Most people outside the industry don’t realize that you’re not surveilled (when flying) over the oceans. From a safety perspective, the ability to have almost real-time position data is exciting for us because we haven’t had it before.”

Nav Canada, UK NATS and the Irish Aviation Authority (IAA), which also participates in controlling North Atlantic traffic, are among partners in the Aireon joint venture, which in early February received control of its final ADS-B receiver payloads from Iridium. With the surveillance network completed, the UK and Canadian ANSPs plan to conduct a two-phased operational trial of the system through November 2020.

UK NATS will track aircraft from its Prestwick Oceanic Control Center; Nav Canada will do so from its Gander oceanic center.

UK NATS presently receives position updates from aircraft flying outside of radar coverage once every 14 min. by satellite-routed controller pilot data link communications. Pilots report their position by high-frequency radio to the IAA. With transponder-equipped aircraft broadcasting their position by ADS-B, UK NATS expects to receive position updates every 5-to-8 seconds.

With vastly improved situational awareness of air traffic, the ANSPs also will be able to close the gap enforced between aircraft by “procedural” separations from about 40 nm longitudinally within tracks to about 17 nm. Lateral separations between tracks will be reduced from 30 nm to 15-to-19 nm during the trial’s second phase, beginning six months from late March.

“Because it’s a big change and a significant reduction in separations, we want to make sure we get it right, which is why we we’re going to do it in two phases,” Kennedy said during an interview March 13 at the World ATM Congress in Madrid.

“ADS-B, giving us the data it gives us, not only makes (the airspace) safer, it will also unlock capacity,” she said. “Also, importantly, it gives the airlines the routes they want, the speeds they want. We think (ADS-B) will deliver on all sorts of fronts.

Bill Carey,