The FAA on January 7, 2026 issued a proposed rulemaking that would require all radio altimeter systems to meet specific minimum performance standards, per the agency's filing as summarized in Eckert Seamans' January 2026 aviation regulatory update. If adopted, the rule would turn the ad-hoc fixes that followed the 5G rollout of 2022 into a standing airworthiness benchmark for every aircraft type carrying the equipment.
This article publishes information, not regulatory advice; operators and certificate holders should rely on the Federal Register text and their own certification specialists.
Why are radio altimeters back on the regulatory agenda?
Radio altimeters measure height above terrain by timing a radio signal bounced off the ground, and they feed autopilots, terrain warning systems, and Category II/III low-visibility approaches. When wireless carriers switched on C-band 5G service near U.S. airports in January 2022, the FAA worried that out-of-band emissions could confuse those receivers, and it imposed buffer zones around runways until operators proved their fleets' altimeters could tolerate the environment.
That episode was handled through temporary directives and equipment substitutions rather than a permanent performance rule. The January 7 proposal closes that gap: instead of case-by-case waivers, manufacturers would have to show a common minimum standard of rejection of interference before the equipment is approved.
The equipment itself is universal. Every commercial jet built for instrument flying carries at least one radio altimeter, and widebodies typically carry several, feeding redundant channels that must agree before an autopilot will fly an automatic landing. That ubiquity is why the FAA chose a performance rule over a type-specific fix: one standard covers the whole installed base, from current-production narrowbodies to older widebodies that will fly for another two decades.
Related stories: FAA Moves to Lift 53-Year Ban on Supersonic Flight Over U.S. Land · Boeing Out-Delivered Airbus in Q1 2026 for the First Time Since the MAX Crisis.
What changes for airlines and travelers?
For carriers, the practical effect is a certification baseline rather than a retrofit order — the proposal governs performance standards for the systems, not an immediate fleet-wide modification. Operators would see the standard applied through type design and future equipment approvals. For travelers, the significance is stability: the approach restrictions that made some bad-weather landings more discretionary in 2022 would rest on certified-altimeter performance instead of blanket distance limits.
What happens next
The proposal enters the standard comment cycle, and the final rule's timing will depend on the docket. Travelers tracking low-visibility operations should watch the Federal Register docket; this page will re-verify details against the published text before any follow-up coverage.