A Southwest commercial aircraft flies past a cell phone tower as it approaches to land at John Wayne Airport in Santa Ana, California U.S. January 18, 2022.
A Southwest commercial aircraft flies past a cell phone tower as it approaches to land at John Wayne Airport in Santa Ana, California U.S. January 18, 2022. Reuters / Mike Blake

The Federal Aviation Administration said Friday that Verizon Communications and AT&T have voluntarily agreed to delay some C-Band 5G usage until July 2023 as air carriers work to retrofit airplanes to ensure they will not face interference.

The two carriers agreed in January to delay through July 5 switching on some wireless towers and depowering others near airports. Verizon said Friday the new agreement will allow it to "lift the voluntary limitations on our 5G network deployment around airports in a staged approach over the coming months meaning even more consumers and businesses will benefit from the tremendous capabilities of 5G technology."

AT&T said with the FAA it had "developed a more tailored approach to controlling signal strength around runways that allows us to activate more towers and increase signal strength." AT&T added that it had voluntarily "chosen in good faith to implement these more tailored precautionary measures so that airlines have additional time to retrofit equipment."

Concerns that the 5G service could interfere with airplane altimeters, which give data on a plane's height above the ground and are crucial for bad-weather landing, led to disruptions at some U.S. airports earlier this year.

In recent months, the Federal Aviation Administration has been urging airlines to complete retrofits of some airplane radio altimeters.

Acting FAA Administrator Billy Nolen on Wednesday urged the chief executives of major U.S. airlines to move quickly to address risks from a 5G wireless rollout by installing filters on radio altimeters, in a bid to avoid potential disruptions at key airports from next month.

Airlines for America, an industry trade group representing American Airlines, Delta Air Lines, United Airlines and others, said at an FAA meeting Friday they learned "the vast majority" of members fleet of 4,800 total aircraft "would need to be retrofitted by July 2023" and raised questions if that is feasible. "Given that the FAA has not even approved solutions nor have manufacturers manufactured these products for most of this fleet, it is not at all clear that carriers can meet what appears to be an arbitrary deadline."

The FAA said Friday "filters and replacement units for the mainline commercial fleet should be available on a schedule that would permit the work to be largely completed by July 2023. After that time, the wireless companies expect to operate their networks in urban areas with minimal restrictions."

Airlines CEOs on Jan. 17 had warned of an impending "catastrophic" aviation crisis that could have grounded almost all traffic because of the 5G deployment.