On July 22, 2026, the Federal Communications Commission voted to adopt rules for auctioning a large block of Upper C-band spectrum to wireless carriers. The decision revives a fight that grounded flights in early 2022: the same airwaves sit close to the frequencies aircraft radio altimeters use.
The FCC says its order (FCC 26-46) will free up 160 megahertz of mid-band spectrum, about 60 percent more than Congress required, with the auction due by mid-2027. The measure passed with Chairman Brendan Carr and Commissioner Olivia Trusty in support, while Commissioner Anna Gomez approved in part and dissented in part.
What the FCC actually approved
The Commission did not simply hand the band to carriers. According to the FCC, the order sets out-of-band emission limits, antenna height restrictions, and base station power limits designed to protect altimeter operations in the neighboring 4.2 to 4.4 GHz band.
The FCC also said it established rebates to help the aviation sector retrofit and upgrade those altimeters, and aligned its clearing timeline with the FAA’s forthcoming radio altimeter requirements. In other words, the wireless rollout and the aircraft fix are meant to move in step.
Why a phone auction touches aviation
A radio altimeter is not the standard barometric altimeter pilots read for cruise altitude. It bounces a radio signal off the ground to measure exact height in the final feet of a landing, and it feeds automatic landing systems used in poor visibility.
Those altimeters operate just above the C-band frequencies carriers want. Aviation groups first flagged the overlap in 2015, warning that strong 5G signals near a runway could produce false altitude readings during the most critical phase of flight.
The concern is not theoretical. In January 2022, AT&T and Verizon delayed switching on C-band service near dozens of US airports after carriers warned of mass cancellations, and some foreign airlines, including Emirates and Japan Airlines, pulled US flights. Operators then agreed to buffer zones and a phased retrofit.
The lasting fix is to make the altimeters themselves tougher. The FAA, which has been reworking how it oversees aircraft certification, has been preparing a requirement for interference-tolerant radio altimeters. Under its earlier proposal roughly 58,600 units would need upgrading or replacement at an estimated cost near $4.5 billion.
Under that proposal, airliners flown under Part 121 and large foreign-registered jets would have to comply first, tied to when the FCC authorizes the new services, with smaller operators given roughly two more years. The airlines that never finished retrofitting after 2022 now face a firm deadline.
The FAA is expected to issue its final radio altimeter rule in the days after the FCC vote, timed to the Commission’s action.
2015
First warnings. Aviation groups flag the overlap between planned C-band 5G and the 4.2 to 4.4 GHz altimeter band.
January 2022
Flights disrupted. AT&T and Verizon delay 5G near US airports after airlines warn of cancellations; some foreign carriers cut US service.
July 2023
Retrofit deadline. A voluntary agreement gives carriers time to fit interference-tolerant altimeters.
July 22, 2026
FCC votes. The Commission adopts rules to auction 160 MHz of Upper C-band, with altimeter safeguards and retrofit rebates.
Expected shortly after
FAA rule. The FAA is set to finalize its interference-tolerant radio altimeter requirement, aligned to the FCC timeline.
Why it matters
The 2022 standoff paused a 5G rollout to protect aircraft. This time the regulators sequenced the two: carriers get their spectrum, but only alongside power limits near runways and a hard altimeter-upgrade deadline for airlines.
Still to come
The FCC has set the auction rules, but the spectrum has not been sold and the FAA’s final altimeter rule was not yet published at the time of the vote. The exact compliance dates depend on both.
Sources and references used for research and fact-checking.