NBAA Collaborating with Industry on Solutions, Timelines for FAA’s Proposed New Radio Altimeter Equipment Requirement

Jan. 16, 2026

NBAA is working with industry stakeholders to ensure both the FAA and FCC understand the challenges with the upcoming FCC spectrum auction and associated impacts on aviation.

The FAA recently published a Notice of Proposed Rulemaking (NPRM), which would require aircraft equipped with radio altimeters to meet specific performance requirements.

“The timelines proposed will be challenging in light of solutions that haven’t yet come to market,” said Heidi Williams, NBAA vice president of air traffic services and infrastructure. “Achieving the proposed rule’s objectives, on any timeline, will require continued collaboration between industry stakeholders, the FAA and standards organizations. It is even more critical that, as we undergo standards development efforts with organizations like RTCA, those standards and the final rule language align.”

This NPRM affects the existing U.S.-registered aircraft fleet and all new aircraft equipped with radio altimeters, whether equipped by regulation or voluntarily. The new radio altimeters must withstand interference from wireless signals in neighboring spectrum bands while providing accurate altitude readings to both pilots and integrated aircraft safety systems.

The proposed rule is the result of the 2025 One Big Beautiful Bill Act, which reinstituted the Federal Communications Commission’s (FCC’s) action authority and directed the agency to complete a system of competitive bidding of the Upper C-band, which includes not less than 100 megahertz in the 3.98-4.2 gigahertz band.

That auction process is scheduled to occur in 2027.

The FCC recently published a companion NPRM to expand next-generation wireless services in the 3.7-4.2 gigahertz band by making as much as 180, and at least 100, megahertz of the Upper C-band available for terrestrial wireless flexible use.

The FAA predicts initial compliance dates to be between 2029 and 2032, with full compliance required two years later. All Part 121 and part 129 aircraft with 30 or more passenger seats or payload capacity of more than 7,500 pounds equipped with a radio altimeter must comply with the minimum performance requirements by the date the FCC authorizes wireless services in the Upper C-band.

All other aircraft equipped with radio altimeters would be required to comply with the same minimum performance requirements two years later.

“We are concerned with the expansive nature of the proposed rule and the associated timelines but will continue to collaborate and work toward solutions that ensure aviation operations remain resilient,” said Williams.

Comments on the proposed rule are due March 9.