Operators: Transport Canada Updates 5G Interference Risk Mitigations

July 8, 2026

Transport Canada (TC) recently issued new guidance on managing interference risk between 5G signals and aircraft radio altimeters (RadAlt). The update, published in Civil Aviation Safety Alert (CASA) No. 2026-08, follows a new, voluntary agreement between Canada’s major telecom service providers.

Certain regulatory 5G spectrum mitigations – including reduced fundamental emissions power levels based on antenna uptilt above the horizon nationwide and exclusion/protection zones at 35 initially protected airports – were planned to sunset in January 2026.

A voluntary agreement extended those mitigations through June 30, and major telecom service providers have since reached an agreement to implement a set of voluntary 5G mitigations after that date, in consultation with TC; Innovation, Science and Economic Development Canada (ISED); and key aviation industry stakeholders.

Mitigation measures that went into effect July 1 include the following:

Mitigations for the 3450-3900 MHz band:

• Base stations keep cross-polarized antennas with equal power distribution
• A stricter spurious emissions limit (-42 dBm/MHz, tightened from -30 dBm/MHz)

Mitigations for the 3650-3900 MHz band:

• Coordination with TC and ISED for tall base stations (>70m) near 245 airports
• A new National Effective Isotropic Radiated Power (EIRP) power mask for base stations in the 3650–3900 MHz band

The participating telecom service providers agreed to these mitigations through Dec. 31, 2027, with TC and ISED reviewing effectiveness of the measures in January 2027 and July 2027, then determining whether the measures can be lifted or should be extended beyond Jan. 1, 2028.

TC encourages all operators to retrofit their aircraft to meet RadAlt tolerance requirements in accordance with Airworthiness Directives CF-2024 (for fixed-wing aircraft) and CF-2024-15 (for rotorcraft). Non-tolerant aircraft may face more restrictive operating limitations in Canadian airspace.

Operators should also report any RadAlt disturbance/interference immediately, using the Radio Altimeter Disturbance/Interference Report form. TC reminds operators these reports are non-punitive.