5G Truce Expected to Avert Many—but Not All—Flight Disruptions

Transportation officials, to secure another standstill from wireless companies technically under another agency’s purview, agreed to “not seek or demand any further delays,” according to a term sheet reviewed by The Wall Street Journal. The deal with Transportation Secretary Pete Buttigieg and FAA chief Steve Dickson also requires that the telecom companies limit their cellular signals near airports for six months, incorporating the carriers’ earlier proposals.

While aviation industry and government officials view 5G travel disruptions as unavoidable, they say the extent of any flight restrictions will depend on continued cooperation in behind-the-scenes work among air-safety regulators, telecom companies’ spectrum experts and aerospace manufacturers’ engineers.

The goal is to carve out buffer zones around certain U.S. airports to satisfy FAA safety concerns while also allowing cellphone providers to roll out faster service to as many customers as possible. The FAA is concerned that the new cellular signals could interfere with key cockpit safety systems. U.S. wireless executives have disputed those claims while acknowledging the need to avoid disrupting air traffic.

“We felt that it was the right thing to do for the flying public, which includes our customers and all of us, to give the FAA a little time to work out its issues with the aviation community and therefore avoid further inconveniencing passengers with additional flight delays,” Verizon VZ 1.03% Chief Executive Hans Vestberg wrote Tuesday in a note to employees.

Verizon and AT&T on Monday agreed to the two-week delay that Mr. Buttigieg had sought after previously declining the request. The last-minute brinkmanship included a decision by the FAA to move ahead with potentially major flight restrictions to take effect on Wednesday, and an airline trade group’s threat to seek an emergency court order, according to people familiar with the matter. The FAA and trade group both held off in the end.

President Biden praised the deal Tuesday, saying in a statement: “This agreement ensures that there will be no disruptions to air operations over the next two weeks and puts us on track to substantially reduce disruptions to air operations when AT&T and Verizon launch 5G.”

The FAA has said it is worried about potential interference with radar altimeters, which measure the distance between aircraft and the ground.

As part of the agreement, the FAA will propose up to 50 priority airports that will be subject to specific wireless-company limits to 5G signals for six months. The negotiations have focused on the size of the protective buffer zones, among other engineering details, people familiar with the matter said.

The telecom companies also will provide the FAA information about where and how they will deploy the new 5G service in the first half of the year, according to the term sheet. Meanwhile, the FAA will work to validate airports and certain radar altimeters are safe, potentially reducing disruptions, while aerospace manufacturers conduct additional testing.

“It’s not a problem that will be solved in two weeks,” said Eric Fanning, CEO of the Aerospace Industries Association. “But an important part of this agreement is to share information, which allows for more effective testing.”

Some AT&T and Verizon customers already have started seeing 5G icons on their smartphones, indicating that their provider has improved their internet service using the latest technical standards. Both companies had planned to enhance that fifth-generation service early this winter using the wireless licenses they acquired last year.

Verizon spent about $53 billion on licenses and other payments to secure the airwaves, more than any other carrier, and is depending on them to keep its cellphone customers satisfied. It also plans to use them to beam home internet service into some residential areas where cable broadband is unavailable or too expensive. The wireless company said Tuesday that turning on the new signals later this month will cover 100 million people with access to speeds up to 10 times faster than existing 4G service.

The agreement for the latest delay began taking shape late Sunday. After the telecom companies rejected U.S. transportation officials’ initial request, Mr. Buttigieg called their CEOs late Sunday, according to people familiar with the conversations.

Mr. Buttigieg conveyed that air-safety regulators would agree to six months of limited wireless signals under rules similar to those the carriers proposed roughly modeled after France’s approach—provided that carriers keep the service offline for another two weeks, these people said.

AT&T’s CEO told Mr. Buttigieg that the terms sounded reasonable, some of these people said. The company told an airline trade group on Monday that it would agree to a two-week pause, people familiar with the matter said.

By Monday, the FAA was preparing to issue about 1,300 official notices that would include restrictions on pilots landing in bad weather starting on Wednesday, people familiar with the matter said. The limits would further add to recent U.S. travel woes: flight cancellations and delays due to pandemic-related staffing issues and winter weather.

Airlines for America, a trade group representing major U.S. passenger and cargo carriers, was preparing to ask a federal court in Washington to block the 5G expansion, people familiar with the matter said. But Biden administration officials asked the trade group to hold off while talks continued with Verizon, according to aviation industry and government officials.

Meanwhile, aviation groups made a public-relations push. They highlighted the dire predictions for air-traffic disruptions and called on the White House to intervene.

As Monday evening wore on, the airline trade group agreed to hold back its litigation, according to aviation and government officials. Later that evening, Verizon joined AT&T and announced it had agreed to wait another two weeks.

Write to Andrew Tangel at Andrew.Tangel@wsj.com and Drew FitzGerald at andrew.fitzgerald@wsj.com