Cellular 5G interference with radio altimeters remains a hot topic

The rollout of 5G telecommunications and the potential interference with aircraft operations remains a hot topic. The FAA, through a 2-Nov-2021 ‘Special Airworthiness Information Bulletin: Risk of Potential Adverse Effects on Radio Altimeters’ provides information to the aviation community and requests information to “…assess the need for mitigation beyond the recommended action in this SAIB.”

“This Special Airworthiness Information Bulletin (SAIB) informs aircraft manufacturers, radio altimeter manufacturers, operators, and pilots of the planned deployment of wireless broadband networks in the 3700-3980 MHz bands, which is scheduled to begin on December 5, 2021 in the 3700-3800 MHz bands. This SAIB recommends that radio altimeter manufacturers, aircraft manufacturers, and operators voluntarily provide to federal authorities specific information related to altimeter design and functionality, specifics on deployment and usage of radio altimeters in aircraft, and that they test and assess their equipment in conjunction with federal authorities…”

The FAA document is accessible through this link, AIR-21-18. The RTCA independent study on the 5G interference topic is available as well.