Navigation — 5G C-Band wireless Broadband Interference with Radio Altimeter System when operating in the contiguous United States of America (U.S.) airspace
- Published
- Effective
- Replaces
- CF-2023-46
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of DHC-8-401 and DHC-8-402 aircraft must comply with operational limitations within 60 days of the directive's effective date, including increased landing distances and prohibitions on certain flap and propeller RPM configurations. They must install specified cockpit labels and brief flight crews on new procedures. Within four months, aircraft must be modified per approved service bulletins to achieve Radio Altimeter Tolerant status, which will terminate the interim restrictions.
Summary
Airworthiness Directive CF-2025-43 issued by Transport Canada addresses interference from 5G C-Band wireless broadband signals affecting the radio altimeter systems on De Havilland Aircraft of Canada Limited DHC-8-401 and DHC-8-402 aeroplanes operating in contiguous U.S. airspace. The directive mandates specific operational limitations and modifications to mitigate erroneous radio altitude data caused by 5G interference. It requires affected aircraft to be configured as Radio Altimeter Tolerant (RAT) aeroplanes to ensure safe operations.
What changed
This new Airworthiness Directive introduces operational restrictions and corrective actions for DHC-8-401 and DHC-8-402 aircraft to mitigate 5G C-Band interference with radio altimeters. It prohibits certain flight operations without RAT configuration, mandates installation of cockpit labels, briefing of flight crews, and prohibits dispatch under specific Minimum Equipment List items. The directive also requires modification of the aircraft within four months to terminate these restrictions.
Why it matters
The directive is critical for aviation professionals as 5G interference can cause erroneous radio altitude readings, increasing pilot workload and potentially compromising landing safety due to delayed weight-on-wheels signals and braking performance. Operators and maintenance teams must ensure compliance to avoid unsafe flight conditions and regulatory penalties. It impacts flight planning, aircraft dispatch, and maintenance scheduling for affected De Havilland DHC-8 models.
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