While ADS-B Out has been mandatory in certain U.S. airspace for two years, Canada opted to delay a similar mandate pending the outcome of trial runs, the first of which began in December.
While other factors (such as a certain coronavirus) may complicate cross-border air travel for some time to come, pilots of FAA-registered aircraft can cross ADS-B off that list until at least 2023.
Canada delayed its own mandate in late 2019, weeks before it would otherwise have taken effect. The delay was in response to lobbying by aviation stakeholders, including AOPA, which, in a letter also signed by many other groups concerned, noted at the time that Canada's space-based approach to airspace surveillance would "have a significant negative impact on Nav Canada's most cost-sensitive users."
The reason for that is diversity—antenna diversity. As aviation stakeholders noted in 2019, Canadian regulators had erroneously assumed that most (or all) general aviation aircraft had antennas mounted on the top and bottom of the aircraft, as required for installation of collision avoidance systems (TCAS II) used in commercial turbine transport aircraft—but not mandatory for aircraft with fewer than 30 passenger seats weighing less than 33,000 pounds that are operated outside of reduced vertical separation minimum airspace.
Canadian regulators, to their credit, pumped the brakes with respect to low-altitude operations, though Nav Canada did implement space-based ADS-B in 2019, working with Aireon to deploy a satellite surveillance solution covering North Atlantic airspace at or above 29,000 feet. A network of Aireon satellites receives 1090 MHz aircraft transmissions and relays the data to be displayed in air traffic control facilities, and the flight decks or ground control stations of other aircraft. (Some remotely piloted aircraft operators utilize ADS-B In for situational awareness.) Subsequently, the diversity portion of the coming mandate has been softened to allow for performance-based equipment that can communicate with the ground.
Using satellites instead of terrestrial radio receivers to monitor ADS-B transmissions reduces the infrastructure cost dramatically but presents problems for aircraft without top-mounted antennas and limits operators to using 1090MHz transponders. On the equipage side of the cost equation, lower-cost options for aircraft have also become available in recent years, including (though not necessarily limited to) tailBeaconX transponders from uAvionix. Technically, tailBeaconX does not have antenna diversity, but achieves the same functionality as a dual-antenna array mounted on the top and bottom of the aircraft with a dipole antenna of vertical fins extending from the device that also doubles as a rear position light. A certified version (tailBeaconX TSO) is listed on the company website for preorder at $2,499, with the supplemental type certificate and approved model list expected soon; the experimental version is listed as a backorder item at the same price.
Nav Canada began ADS-B trials to evaluate equipment and procedures, and gain additional operational experience and feedback from aviators on December 10, starting with the Montreal Flight Information Region, with the Edmonton (Alberta) FIR to follow soon. This marked the first fully realized use of ADS-B at lower altitudes, putting to a real-world test how well the space-based system can track aircraft at lower altitudes. It also created an opportunity for pilots to plan, file, and fly with the full benefits of ADS-B. Participation is optional, and largely automated, though pilots will need to input a flight identification number that matches exactly the aircraft identification in a filed flight plan, and have a 1090 MHz ADS-B transponder that is able to transmit to satellites, for their flight to generate data for the trial.
The voluntary nature is a reflection of the fact that Nav Canada and Transport Canada have focused attention more in recent years on the benefits than on the coming mandate, which is now on track to take effect in 2023 within Class A and B airspace, and be applied to Class C, D, and E airspace no sooner than 2026, according to a recent briefing document prepared by Nav Canada. The rulemaking process to establish equipment standards and update operational rules has not yet begun.
The benefits of ADS-B beyond shared situational awareness and more efficient use of airspace include dramatically speeding up the process of locating downed aircraft in remote areas, effectively taking the need for "search" out of "search and rescue."
Nav Canada noted in an August blog post that the transoceanic application of ADS-B (at and above 29,000 feet) has improved safety, with 2020 going down as the first year on record when no aircraft spent any amount of time in unprotected airspace. Prior to 2019, position updates from aircraft were separated by 14 minutes or more, meaning aircraft could deviate significantly from assigned altitude or expected course before air traffic controllers became aware. Since the space-based network went live, each flight's position, altitude, and speed have been updated on ATC screens about twice each second.