The Federal Aviation Administration (FAA) published a final rule establishing the Requirements for Interference-Tolerant Radio Altimeter Systems. This regulation ensures that aviation operations remain safe and reliable as the Federal Communications Commission (FCC) prepares to allocate spectrum for terrestrial wireless use.
The rule supports the FCC’s July 2026 Report and Order, which makes 160 megahertz of the Upper C-band available for flexible use. To protect against interference from wireless signals in neighboring bands, new regulations require radio altimeters to withstand such signals and continue providing accurate altitude readings to pilots and integrated aircraft safety systems.
The FAA set specific compliance deadlines based on the aircraft’s operating rules. Aircraft equipped with radio altimeters operating under 14 CFR Part 121, and those operating under 14 CFR Part 129 with 30 or more passenger seats or a payload capacity exceeding 7,500 pounds, must meet these minimum performance requirements by December 30, 2030. This deadline occurs before the FCC authorizes the use of the Upper C-band for new wireless services.
All other aircraft equipped with radio altimeters required to comply with 14 CFR Part 91 must meet the same standards by October 31, 2034. This broader group includes aircraft operating under 14 CFR Parts 125, 133, 135, 136, 137, and 194. It also covers all other aircraft operating under 14 CFR Part 129 that were not subject to the initial 2030 deadline.
The rule affects 14 CFR Parts 91, 121, and 129. It was published under Docket No. FAA-2025-5666, Amendment Nos. 91-384, 121-396 and 129-56. The regulation became effective on September 29, 2026.
Summary written for CheckAero from the official document. It is not legal advice; read the full text before acting.