Canada 5G Aviation Mitigation Measures Face Phased Sunset by 2028

Transport Canada has announced a phased plan to sunset 5G aviation mitigation measures, shifting responsibility for radio altimeter safety from spectrum providers to aircraft operators. While telecom operators have voluntarily extended existing protections through June 30, 2026, complete removal of all spectrum mitigations is scheduled for Jan. 1, 2028.

According to Civil Aviation Safety Alerts (CASA) 2025-05 and 2025-14, the first major phase began Jan. 1, 2026, when nationwide reduced power levels based on antenna uptilt and exclusion zones around 35 protected airports were removed. Only reduced power at runway ends in the 3800 MHz band remains, via specific elevation masks. The shift represents a transition from a "shield the airports" model to a "harden the airplanes" approach. Transport Canada is urging operators to retrofit fleets to meet radio altimeter tolerant standards, referencing Airworthiness Directives CF-2024-14 and CF-2024-15. The agency is leveraging the FAA's Radio Altimeter Tolerant standard but has stated it does not intend to impose a broad-based retrofit mandate — operators must determine necessary upgrades based on their specific fleet and operational requirements.

Industry groups including the National Airlines Council of Canada have warned that non-tolerant aircraft may face significant operational restrictions, including the inability to conduct CAT II/III instrument landings, autolands, or use Head-up Guidance Systems in low-visibility conditions. The DHC-8-401/402 Airworthiness Directive CF-2025-55 further underscores that as mitigation sunset dates approach, aircraft operating in Canadian airspace must be configured as tolerant to avoid dispatch and landing performance restrictions. The move broadly aligns Canada with the U.S. C-band regulatory environment, though Ottawa diverges from Washington by stopping short of a mandatory fleet-wide retrofit. Pilots are encouraged to report any radio altimeter disturbances via official reporting forms to assist regulators in monitoring the transition. For a detailed technical overview, see the Radio altimeter and 5G interference overview.