Suddenly I see…

Today, air traffic control officers (ATCOs) on each side of the North Atlantic can see the aircraft they are controlling as they fly between Europe and North America.

It is almost impossible to convey the huge significance of this boring and apparently obvious piece of information, because most people don’t know that – yesterday – the same ATCOs couldn’t see the aircraft they were responsible for. They never had been able to see them, because the machines were outside radar range.

When flying between North American and Europe, until now aircraft of all kinds have always been invisible to air traffic control from the time they were about 350km off the coast on either side.

Under yesterday’s system, ATCOs knew approximately where each aircraft was because the pilots reported their position, their height and an estimate for the next reporting point every 15min or so. This worked safely because aircraft were painstakingly released into their pre-cleared, one-way oceanic tracks at specific heights, time intervals, and speeds, so they would maintain separation vertically and horizontally.

That system is a well-tried air traffic management (ATM) technique known as procedural control, and most of the world will continue to control air traffic procedurally over almost all oceanic and wilderness areas for some years yet.

In fact only 30% of the earth’s surface has radar coverage enabling aircraft surveillance for air traffic management (ATM) purposes.

But now, a new global constellation of 66 low-earth-orbit smart satellites – launched over the last decade by satcoms company Iridium Communications – each carries a device that links aircraft ADS-B datalink signals to ATM centres. Aircraft-mounted ADS-B (automatic dependent surveillance – broadcast) streams information about the aircraft’s position, height and much more. This enables ATCOs to track the aircraft in real time, with a radar-like update rate of 8 seconds.

Here’s the history (this announcement should really be preceded by a trumpet fanfare!): US-headquartered communications technology company Aireon yesterday announced that its space-based air traffic surveillance system was switched on, and active surveillance trials involving ANSPs (air navigation service providers) Nav Canada and UK NATS have begun on the busy North Atlantic routes that each manages from its respective oceanic base either side of the sea.

Aireon CEO Don Thoma was able to boast that “For the first time in history, we can surveil all ADS-B-equipped aircraft anywhere on Earth.”

Well, it’s true that they are set up to do so, but not all the world’s ANSPs are ready for it yet. Those who are ready include Nav Canada and NATS, but also the Irish Aviation Authority, Italy’s Enav, and Denmark’s Naviair.

The European Aviation Safety Agency (EASA) is in the process of certificating the provision – by Aireon – of space-based surveillance over the whole continent. That will be another first: the provision of surveillance capability by an organisation that is not an ANSP nor the military.

Others will follow.