ADS-B with diversity required in Canada Class A

A coalition of aviation industry groups has been asking Transport Canada to delay a mandate for satellite-based ADS-B since 2022, noting that the policy amounts to a new equipage mandate for operators based in the United States, where ground-based ADS-B systems are used. The coalition, which also includes the General Aviation Manufacturers Association, Canadian Owners and Pilots Association, Garmin International, and the Canadian Business Aviation Association, noted that there was not enough time available to equip aircraft with antenna diversity (either dipole antennas or separate antennas on the top and bottom of an aircraft) required to report aircraft position and other data to the network via satellite. In addition, information about whether specific equipment could show compliance with the mandate has not been available to industry (it was only provided within the past few weeks).

Ben Girard, Nav Canada vice president and chief of operations, responded in 2022 by announcing the delay of the new ADS-B mandate until August 10 for Class A airspace, with the Class B airspace requirement to follow on May 16, 2024. “We recognize that supply chain issues may be impacting some of our customers in terms of their ability to acquire and install an appropriate ADS-B Out equipment in a timely fashion,” Girard wrote. “In recognition of the challenges that these customers are facing, the Canadian equipage mandate will be delayed to provide additional time to install an appropriate transponder.”

It is unclear how many aircraft have since been equipped with antenna diversity, and the coming Class B mandate raises an additional concern: Nav Canada will reportedly need to bring dozens of ground stations online around Toronto; Montreal; and Vancouver, British Columbia, because frequency interference makes satellite-based ADS-B information unreliable for traffic management in the most congested airspace. In light of this development, many are asking why the mandate is being implemented in the first place.

With the Class A mandate effective on August 10, Nav Canada created an online form for use by operators and pilots of aircraft unable to meet the new ADS-B requirements. Individuals may request an accommodation for a single flight, and the form advises submitting such requests at least three business days in advance, guidance amplified in an aeronautical information circular on the topic. The circular states that approvals will be based on three principles: safety, available air traffic control separation service, and impacts on other airspace users.

“Assessing ADS-B accommodation requests will be a manual process and will take time for each flight,” Nav Canada wrote, noting the agency “will need to assess alternative surveillance means for each flight and determine if all the affected air traffic control specialties will be able to adequately handle the procedural-separation needs of unequipped aircraft on requested routes and altitudes.”

The circular notes that a 90-day “transition period” will be granted through November 8, to allow aircraft operators to “acclimate,” and noncompliant aircraft will not be subject to aviation occurrence reports that could otherwise lead to enforcement action. “During this 90-day period, [Nav Canada] will evaluate the removal of certain automation filters that may have previously prevented some ADS-B equipped aircraft from being visible to controllers below FL290.”

AOPA Director of Airspace, Air Traffic, and Security Jim McClay said the coalition continues to support the safety benefits of ADS-B implementation, broadly, but continues to urge the Canadian government to improve its coordination with industry and to reconsider the scope of the mandate, particularly when it comes to other airspace classes that could be subject to the same mandate, though not before 2026.