Despite objections by U.S. and Canadian general and business aviation user and avionics associations, Nav Canada is not budging on its requirement for ADS-B diversity antenna configurations, meaning antennas mounted on the top and the bottom of aircraft. The mandate is effective beginning Jan. 1, 2021.
Nav Canada, the company that operates the nation’s ATC system, claims these antenna configurations are needed to improve ADS-B reception and performance, as well as support five-nm aircraft separation using ADS-B. However, in a letter to Nav Canada, AEA, AOPA, CBAA, GAMA, NBAA, Garmin and four other organizations contend that the cost to equip small aircraft with diversity is “significant and installations of this type of system are rare.”
In its response, Nav Canada noted that it is not implementing the requirement below 12,500 feet, where it says the majority of small general aviation aircraft fly. Furthermore, the mandate will provide “our affected customers with the efficiency and safety benefits to justify the expense they will incur to upgrade their avionics to meet the performance requirements,” Nav Canada said, adding that the requirement “will harmonize with U.S. and European ADS-B Out mandates.”
The requirement to be equipped with diversity antenna systems will be implemented in two phases. Phase 1 starts Jan. 1, 2021, in Class A airspace between FL180 and FL600, and in Class E Airspace above FL600; Phase 2 starts on Jan. 1, 2022, in Class B airspace between 12,500 feet and FL180.
Nav Canada is also considering a Phase 3 that would broaden the mandate to Class C and D airspace around specific airports. Nav Canada said it plans additional stakeholder consultations and that if there is a Phase 3, it would not be implemented before January 2023.