Nov. 4, 2021
A coalition of aviation groups, including NBAA, has called on the Federal Communications Commission (FCC) to address industry concerns about the imminent rollout of expanded 5G telecommunications networks, as the FAA recently issued a Special Airworthiness Information Bulletin (SAIB) cautioning manufacturers and operators of their potential hazardous effects to radar (or radio) altimeter accuracy.
On Dec. 5, wireless broadband networks in the 3700-3980 MHz bands will launch in dozens of U.S. cities. Also referred to as the C-band, those frequencies are adjacent to those used by radar altimeters in commercial aircraft and helicopters, including many business aircraft.
In the SAIB released Nov. 2, the FAA recommends that aircraft and radar altimeter 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.”
Further mitigations beyond the scope of the SAIB may be needed, the agency added, including the possibility of an airworthiness directive.
NBAA has long worked to ensure the integrity of vital aviation safety systems as 5G networks take hold. Also on Nov. 2, the association joined with 20 other stakeholders in submitting an ex parte letter to FCC Secretary Marlene Dortch, petitioning the agency to address industry concerns the FCC’s approval of the new 5G networks does not fully account for potential interference to radar altimeter accuracy.
“The lack of necessary data in the FCC public record for the Aviation Community to make data-driven decisions on air safety further reinforces the need for direct discussions between the Commission, the FAA, 5G interests and the aviation industry,” reads the coalition letter. “Such an assessment cannot rely on the typical values or non-specific estimates that have been provided for some of the 5G parameters in the public record, and instead must use precise parameters, such as regulatory limits or license conditions that can be assured to accurately define all operations.”
Without such steps, the coalition added, the FCC risks “fail[ing] to protect the public, aircraft passengers and crew from harm while also hurting our nation’s economic viability.”
Heidi Williams, NBAA’s director of air traffic services and infrastructure, emphasized the industry supports making spectrum available to next-generation wireless communications technologies. “However, the FAA shares our concerns these new technologies may compromise the integrity of important aviation safety systems unless proper mitigations are implemented,” she said.