- The FAA issued a final rule requiring 5G-tolerant radio altimeters for all U.S.-operating aircraft.
- Major scheduled air carriers must complete fleet equipment upgrades by December 30, 2030.
- Smaller aviation operators have until October 31, 2034 to meet the new safety standards.
The Federal Aviation Administration issued a final rule July 24 requiring aircraft operating in the United States to use radio altimeter systems that can withstand interference from 5G wireless signals. The FAA final rule creates a permanent equipment standard after years of conflict between aviation and telecommunications companies.
The regulation, titled “Requirements for Interference-Tolerant Radio Altimeter Systems,” appeared in the Federal Register on July 31. It targets signals in the Upper C-band, the 3.98–4.2 GHz range used for 5G services near radio altimeter frequencies.
Free toolDS-160 Form Filling Online Helper Tool
Airlines must retrofit their fleets by different deadlines. Large scheduled carriers face the earlier date, while smaller commercial and general aviation operators receive additional time.
The mandate covers about 58,500 radio altimeter units across the U.S. aviation fleet. Regulators estimate that replacing or upgrading them will cost the industry more than $4.49 billion.
The equipment protects aircraft during their most demanding phases of flight. Radio altimeters directly measure an aircraft’s distance from the ground.
Major carriers face a 2030 deadline
Scheduled air carriers operating under Part 121 and large foreign airliners operating under Part 129 must comply by December 30, 2030. Those operators will need to plan upgrades across fleets that rely on radio altimeter readings during approaches, landings and other low-altitude operations.
All other aircraft equipped with radio altimeters have until October 31, 2034. That category includes aircraft operating under Part 91 and Part 135, among others.
| Operator category | Compliance deadline |
|---|---|
| Scheduled air carriers, Part 121 | December 30, 2030 |
| Large foreign airliners, Part 129 | December 30, 2030 |
| Other aircraft equipped with radio altimeters, including Part 91 and Part 135 | October 31, 2034 |
The longer timetable gives smaller operators more time to replace equipment. Their per-aircraft costs may range from $40,000 to $120,000 unless they qualify for financial assistance.
The altimeter feeds several automated safety systems
An aircraft’s radio altimeter is the only sensor that directly measures the distance between the aircraft and the ground. Its readings support automatic landing systems, Ground Proximity Warning Systems, Terrain Awareness and Warning Systems, and wind shear detection.
Those systems can become unreliable if nearby 5G transmitters interfere with altimeter signals. The risk is greatest during low-visibility approaches, when crews and automated systems have less room to correct inaccurate information.
The 2022 5G rollout produced foggy-morning delays and flight cancellations tied to interference concerns. The new requirement is intended to prevent those disruptions as aircraft receive upgraded equipment.
Auction proceeds will help fund the upgrades
An FCC-managed rebate program will offset some costs for domestic operators. The program uses proceeds from 5G spectrum auctions to help pay for compliant equipment.
Congress restored the FCC’s authority to conduct those auctions through the One Big Beautiful Bill Act, signed July 4, 2025. The legislation made 160 megahertz of spectrum available for 5G use and established the funding framework for the aviation safety upgrades.
The rule therefore connects two federal priorities: expanding wireless capacity and ensuring aircraft can operate safely near the new signals. Operators still must meet the FAA’s equipment requirements by the deadlines assigned to their aircraft category.
Operators must replace or upgrade thousands of units
The retrofit effort will involve either replacing existing radio altimeters or upgrading them so they can tolerate interference. The total estimate covers aircraft throughout the U.S. fleet, rather than only passenger jets.
Small operators face the later deadline but may encounter higher costs per aircraft because upgrades are spread across smaller fleets. The rebate program could reduce those expenses for eligible domestic operators.
The agency’s rule follows a dispute that lasted years as aviation officials, airlines and telecommunications companies worked around the risk posed by adjacent-band transmissions. The final standard moves the industry away from temporary measures and toward equipment designed for the radio environment created by expanded 5G service.
The first compliance date arrives on December 30, 2030. Operators covered by Part 121 and Part 129 will have to complete their fleet planning before then, while the remaining aircraft category has until October 31, 2034.
