EASA AD CF-2025-31
Navigation — Radio Altimeter System — Introduction of a Radio Frequency Filter to Decrease Risk of Interference from 5G C-Band Wireless Telecommunication Service on the Radio Altimeter System When Operating in Canada
Summary
Airworthiness Directive CF-2025-31 titled 'Navigation — Radio Altimeter System — Introduction of a Radio Frequency Filter to Decrease Risk of Interference from 5G C-Band Wireless Telecommunication Service on the Radio Altimeter System When Operating in Canada' mandates modifications for MHI RJ Aviation ULC aeroplanes, including models CL-600-2B19, CL-600-2C10, CL-600-2C11, CL-600-2D15, CL-600-2D24, and CL-600-2E25. The directive addresses potential interference risks to radio altimeters caused by 5G C-Band wireless telecommunication services in Canada. It requires installation of radio frequency filters on radio altimeters to mitigate these risks.
What Changed
This new Airworthiness Directive introduces the mandatory installation of radio frequency bandpass filters on operational radio altimeters of affected MHI RJ Aviation ULC aircraft to reduce interference from 5G C-Band signals. It specifies different service bulletins for various aircraft models and provides compliance options for aircraft with dual radio altimeters. The directive is an interim action anticipating further regulatory updates due to evolving 5G spectrum usage.
Why It Matters
This directive is critical for aviation safety as interference from 5G C-Band wireless services can impair radio altimeter performance, potentially affecting critical flight systems and alerts. Operators and maintenance organizations must ensure compliance to avoid operational restrictions and maintain airworthiness. The directive also prepares stakeholders for future changes in spectrum management that could impact radio altimeter reliability.
What To Do
Operators of affected MHI RJ Aviation ULC aircraft must install the specified radio frequency filters on their radio altimeters by January 1, 2026, or before the next flight in Canada for certain models. Compliance involves following the instructions in the relevant MHIRJ service bulletins approved by Transport Canada. Aircraft with dual radio altimeters have specific installation and deactivation options to remain compliant.